Biology: Membrane Transport and Osmosis
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Questions and Answers

Which of the following is NOT a characteristic of the plasma membrane?

  • It is permeable to all types of molecules. (correct)
  • It is semi-permeable.
  • It is impermeable to charged molecules.
  • It is selectively permeable.
  • What is the primary function of osmosis?

  • To generate energy
  • To regulate temperature
  • To synthesize proteins
  • To equalize the concentration of a solution (correct)
  • What type of transport does not require energy?

  • Active transport
  • Endocytosis
  • Passive transport (correct)
  • Facilitated diffusion
  • What is the name of the proteins that allow passive movement of solutes through the membrane?

    <p>Channel proteins</p> Signup and view all the answers

    What is the term for the movement of water through a semi-permeable membrane to equalize the concentration of a solution?

    <p>Osmosis</p> Signup and view all the answers

    What is the term for the movement of molecules from an area of higher concentration to an area of lower concentration?

    <p>Diffusion</p> Signup and view all the answers

    What is the term for the proteins that allow specific substances to pass through the membrane?

    <p>Carrier proteins</p> Signup and view all the answers

    What is the term for the movement of molecules through a membrane with the assistance of transport proteins?

    <p>Facilitated diffusion</p> Signup and view all the answers

    What is the main function of biological membranes in terms of water movement?

    <p>To act as a barrier for water movement</p> Signup and view all the answers

    What is the term for the ability of a biological membrane to allow certain molecules to pass through while keeping others out?

    <p>Selective permeability</p> Signup and view all the answers

    What is the function of the phosphate group in the phospholipid bilayer?

    <p>To interact with the watery environment</p> Signup and view all the answers

    What is the result of a cell being placed in a hypotonic solution?

    <p>The cell will swell</p> Signup and view all the answers

    What is the role of membrane transport proteins in biological membranes?

    <p>To control the movement of substances into and out of cells</p> Signup and view all the answers

    What is the term for the process by which cells regulate the amount of water in their surroundings?

    <p>Osmoregulation</p> Signup and view all the answers

    What is the function of the lipid tails in the phospholipid bilayer?

    <p>To remain water-resistant</p> Signup and view all the answers

    What is the role of cell adhesion in biological membranes?

    <p>To facilitate the interaction between cells</p> Signup and view all the answers

    What is the main function of aquaporin proteins?

    <p>To form pores that allow passage of movement of water by osmosis</p> Signup and view all the answers

    What is the purpose of Na+/K+-ATPase pumps?

    <p>To move 3 Na+ out and 2 K+ into the cell</p> Signup and view all the answers

    What is the term for the movement of molecules from an area of high concentration to an area of low concentration?

    <p>Passive transport</p> Signup and view all the answers

    What is the name of the process by which cells take in material from outside the cell?

    <p>Endocytosis</p> Signup and view all the answers

    What is the term for a solution that has the same osmotic pressure as the cell?

    <p>Isotonic</p> Signup and view all the answers

    What is the term for a solution that has a higher osmotic pressure than the cell?

    <p>Hypertonic</p> Signup and view all the answers

    What is the purpose of intravenous fluid therapy?

    <p>To maintain the body's electrolyte balance</p> Signup and view all the answers

    What is the term for the accumulation of excess water in the tissues?

    <p>Oedema</p> Signup and view all the answers

    What is the term for the movement of water out of a cell?

    <p>Cytolysis</p> Signup and view all the answers

    What is the term for a carrier protein that binds to multiple molecules and transports them across the cell membrane?

    <p>Symporter</p> Signup and view all the answers

    What is the primary purpose of receptors in cell signaling?

    <p>To bind to the signal or ligand and produce a response</p> Signup and view all the answers

    What is the role of second messengers in cell signaling?

    <p>To transmit signals from receptors to effector proteins</p> Signup and view all the answers

    What is the primary function of intercellular signaling?

    <p>To communicate between cells</p> Signup and view all the answers

    What is the term for the communication between cells?

    <p>Intercellular signaling</p> Signup and view all the answers

    What is the primary function of receptors in intercellular signaling?

    <p>To bind to the signal or ligand and produce a response</p> Signup and view all the answers

    What is the term for the process by which cells respond to changes in their environment?

    <p>Cell signaling</p> Signup and view all the answers

    What is the primary function of intracellular signaling?

    <p>To respond to changes in the cell's environment</p> Signup and view all the answers

    What is the term for the proteins that enable cell-cell communication?

    <p>Receptors</p> Signup and view all the answers

    What type of signaling involves a special structure called a synapse?

    <p>Synaptic signalling</p> Signup and view all the answers

    What type of molecule is secreted by the target cell in autocrine signalling?

    <p>Prostaglandin</p> Signup and view all the answers

    What is the main difference between autocrine, paracrine, and endocrine signalling?

    <p>Distance of signal transmission</p> Signup and view all the answers

    What is the function of the synapse in synaptic signalling?

    <p>To transmit the signal</p> Signup and view all the answers

    How do cells respond to signals in autocrine signalling?

    <p>By secreting signal molecules</p> Signup and view all the answers

    What type of signalling occurs between neuron cell and effector cells?

    <p>Synaptic signalling</p> Signup and view all the answers

    What is the primary function of gap junctions in cell-to-cell communication?

    <p>To allow direct transfer of ions or small molecules between cells</p> Signup and view all the answers

    What is the characteristic of lipophilic hormone molecules?

    <p>They are lipophilic and bind to intracellular receptors</p> Signup and view all the answers

    What is the primary function of paracrine signaling?

    <p>To allow local signaling between adjacent cells without entering the blood circulation</p> Signup and view all the answers

    What is the characteristic of autocrine signaling?

    <p>Signaling within a single cell</p> Signup and view all the answers

    What is the primary function of connexons in gap junctions?

    <p>To form a hydrophilic channel that allows direct communication between cells</p> Signup and view all the answers

    What is the characteristic of hydrophilic hormone molecules?

    <p>They are hydrophilic and bind to surface receptors</p> Signup and view all the answers

    What is the primary function of endocrine signaling?

    <p>To produce hormones that travel through the blood stream to distant cells</p> Signup and view all the answers

    What is the characteristic of direct signaling?

    <p>Signaling between adjacent cells through gap junctions</p> Signup and view all the answers

    What is the primary function of the coagulation cascade?

    <p>To form a fibrin clot</p> Signup and view all the answers

    What is the result of an imbalance in the coagulation and fibrinolytic cascades?

    <p>Either excessive clotting or excessive bleeding occurs</p> Signup and view all the answers

    What is the primary function of the fibrinolytic cascade?

    <p>To break down fibrin clots</p> Signup and view all the answers

    What are the four necessary steps for hemostasis to be achieved?

    <p>Reflex vasoconstriction, initial platelet plug, coagulation cascade, fibrin stabilisation</p> Signup and view all the answers

    What is the purpose of the kinin cascade?

    <p>To regulate inflammation</p> Signup and view all the answers

    What is the primary function of the complement cascade?

    <p>To regulate inflammation</p> Signup and view all the answers

    What is the result of the coagulation cascade?

    <p>A stable fibrin clot</p> Signup and view all the answers

    What is the primary function of the plasma proteinase cascades?

    <p>To form a fibrin clot</p> Signup and view all the answers

    What is the primary response of platelets when they come into contact with extravascular material?

    <p>They change shape, degranulate, and aggregate</p> Signup and view all the answers

    What is the main function of tissue factor in secondary haemostasis?

    <p>To activate the extrinsic coagulation cascade</p> Signup and view all the answers

    What is the end result of the coagulation cascade?

    <p>The formation of a solid permanent plug</p> Signup and view all the answers

    What is the role of thrombomodulin in counter-regulatory mechanisms?

    <p>To inhibit the coagulation cascade</p> Signup and view all the answers

    What is the primary function of t-PA in counter-regulatory mechanisms?

    <p>To generate fibrinolytic plasmin</p> Signup and view all the answers

    What is the ultimate goal of counter-regulatory mechanisms?

    <p>To restrict the haemostatic plug to the site of injury</p> Signup and view all the answers

    What is the relationship between the coagulation cascade and the fibrinolytic cascade?

    <p>They are complementary</p> Signup and view all the answers

    What is the net result of the counter-regulatory mechanisms?

    <p>Restricted coagulation</p> Signup and view all the answers

    What is the primary function of platelet adhesion and activation in primary haemostasis?

    <p>To form a temporary primary haemostatic plug</p> Signup and view all the answers

    Which of the following proteins is involved in the fibrinolytic cascade?

    <p>Plasmin</p> Signup and view all the answers

    What is the primary function of the coagulation cascade?

    <p>To form a blood clot</p> Signup and view all the answers

    What is the primary function of the kinin cascade?

    <p>To regulate blood pressure</p> Signup and view all the answers

    What is the primary function of the complement cascade?

    <p>To release inflammatory mediators</p> Signup and view all the answers

    What is the primary function of albumin in plasma?

    <p>To transport proteins and hormones</p> Signup and view all the answers

    What is the primary function of the fibrinolytic cascade?

    <p>To break down fibrin clots</p> Signup and view all the answers

    What is the primary function of endothelin release in primary haemostasis?

    <p>To cause vasoconstriction</p> Signup and view all the answers

    What is the primary function of the action potential?

    <p>To generate electrical signals in response to stimuli</p> Signup and view all the answers

    What is the primary function of the resting membrane potential?

    <p>To maintain the electrical potential difference between the inside and outside of the cell</p> Signup and view all the answers

    What is the role of neurotransmitters in nerve conduction?

    <p>To convert electrical signals to chemical signals across the synapse</p> Signup and view all the answers

    What is the primary function of the synapse?

    <p>To allow for communication between cells through the release of neurotransmitters</p> Signup and view all the answers

    What determines the conduction velocity of nerve impulses?

    <p>The diameter of the axon</p> Signup and view all the answers

    What is the primary function of membrane potential in nerve conduction?

    <p>To maintain the electrical potential difference between the inside and outside of the cell</p> Signup and view all the answers

    What is the primary function of the voltage-gated Na+ channels in action potential generation?

    <p>To depolarize the cell membrane</p> Signup and view all the answers

    What is the primary function of the voltage-gated K+ channels during action potential generation?

    <p>To repolarize the cell membrane</p> Signup and view all the answers

    What is the primary function of the Na+/K+ pump during the resting state of the neuron?

    <p>To maintain the resting membrane potential</p> Signup and view all the answers

    What is the primary function of the synapse in synaptic signaling?

    <p>To allow communication between neurons or between neurons and effectors</p> Signup and view all the answers

    What is the primary function of myelin in nerve conduction?

    <p>To increase the nerve conduction velocity</p> Signup and view all the answers

    What is the primary function of the refractory period during action potential generation?

    <p>To allow the neuron to respond to subsequent stimuli</p> Signup and view all the answers

    What is the primary function of the axon in nerve conduction?

    <p>To propagate the action potential</p> Signup and view all the answers

    What is the primary function of the Ranvier nodes in nerve conduction?

    <p>To propagate the action potential</p> Signup and view all the answers

    What is the primary function of neurotransmitters in the synapse?

    <p>To transmit signals from a neuron to another neuron or target cell across a synapse</p> Signup and view all the answers

    What is the result of the influx of Na+ ions in the action potential?

    <p>Depolarization</p> Signup and view all the answers

    Which type of nerve fibers are responsible for transmitting sharp, localized pain?

    <p>Aδ fibers</p> Signup and view all the answers

    What is the mechanism of action of local anesthetics?

    <p>Blocking the influx of Na+ ions</p> Signup and view all the answers

    What is the primary function of excitatory neurotransmitters?

    <p>To increase the likelihood of the postsynaptic neuron firing</p> Signup and view all the answers

    What is the role of γ-aminobutyric acid (GABA) in the synapse?

    <p>To decrease the likelihood of the postsynaptic neuron firing</p> Signup and view all the answers

    What is the primary function of the synapse?

    <p>To transmit signals from one neuron to another or to a target cell</p> Signup and view all the answers

    What is the result of the binding of lignocaine to voltage-gated Na+ channels?

    <p>Blockade of the influx of Na+ ions</p> Signup and view all the answers

    What is the site of collagen maturation?

    <p>Extracellularly</p> Signup and view all the answers

    What is the characteristic of elastin that allows it to act like a 'rubber band'?

    <p>Hydrophobic uncoiling domains</p> Signup and view all the answers

    What is the main cause of oral submucosal fibrosis?

    <p>Chronic consumption of areca nut</p> Signup and view all the answers

    What is the primary function of glycosaminoglycans in the extracellular matrix?

    <p>Attract and trap water</p> Signup and view all the answers

    What is the characteristic of proteoglycans?

    <p>Long, unbranched polysaccharides</p> Signup and view all the answers

    What is the result of the strong negative charge of glycosaminoglycans?

    <p>Attraction and trapping of water</p> Signup and view all the answers

    What is the significance of proteoglycans and glycosaminoglycans in the extracellular matrix?

    <p>Maintain tissue hydration and pressure</p> Signup and view all the answers

    What is the characteristic of elastin that allows it to function like collagen?

    <p>Hydrophobic uncoiling domains</p> Signup and view all the answers

    Which of the following glycosaminoglycans is not sulphated?

    <p>Hyaluronic acid</p> Signup and view all the answers

    What is the primary function of proteoglycans in the extracellular matrix?

    <p>To regulate a wide range of biological activities</p> Signup and view all the answers

    What is the characteristic of hyaluronic acid that makes it a 'goo' molecule?

    <p>Its extremely long chains</p> Signup and view all the answers

    What is the primary location of heparan sulphate synthesis?

    <p>Golgi apparatus</p> Signup and view all the answers

    What is the primary function of proteoglycans in the extracellular matrix, besides regulating biological activities?

    <p>To act as the 'filler' of ECM space</p> Signup and view all the answers

    What is the primary difference between hyaluronic acid and heparan sulphate?

    <p>Their sulphation levels</p> Signup and view all the answers

    What is the primary function of Matrix Metalloproteinases (MMPs)?

    <p>To break down extracellular matrix proteins</p> Signup and view all the answers

    What is the main difference between Loose Connective Tissue and Dense Connective Tissue?

    <p>The arrangement of collagen fibers</p> Signup and view all the answers

    What is the function of Hyaluronidase?

    <p>To break down hyaluronic acid</p> Signup and view all the answers

    What is the primary function of Tendons?

    <p>To connect bones to muscles</p> Signup and view all the answers

    What is the main component of the extracellular matrix in Bone?

    <p>Calcified collagen</p> Signup and view all the answers

    What is the function of Osteoclasts in Bone Remodeling?

    <p>To break down bone matrix</p> Signup and view all the answers

    What is the primary function of Adipose Tissue?

    <p>To store energy in the form of triglycerides</p> Signup and view all the answers

    What is the main component of the extracellular matrix in Connective Tissue?

    <p>Collagen</p> Signup and view all the answers

    What is the function of Serine Proteinases?

    <p>To break down extracellular matrix proteins</p> Signup and view all the answers

    What is the primary function of Connective Tissue?

    <p>To provide structural support to organs</p> Signup and view all the answers

    What is a characteristic of epithelial cells?

    <p>They are tightly bound together.</p> Signup and view all the answers

    What is a function of epithelial cells in the small intestine?

    <p>Absorption of nutrients</p> Signup and view all the answers

    What is a characteristic of the transformation zone in the vagina to cervix?

    <p>It is vulnerable to HPV invasion and subsequent immortalisation of cervical epithelial cells</p> Signup and view all the answers

    What is a function of epithelial cells in the lung alveolus?

    <p>Gas exchange</p> Signup and view all the answers

    What is a function of epithelial cells in the kidneys?

    <p>Excretion of waste products</p> Signup and view all the answers

    What is a characteristic of epithelial cells in general?

    <p>They have distinct polarity</p> Signup and view all the answers

    What is the characteristic of the Stratified squamous epithelial tissue?

    <p>It has multiple layers of cells with the apical surface exposed to a cavity or the outside environment.</p> Signup and view all the answers

    What is the role of desmosomes in epithelial tissue?

    <p>To anchor intermediate filaments to the cell membrane</p> Signup and view all the answers

    What is the function of hemidesmosomes in epithelial tissue?

    <p>To anchor cells to the basement membrane</p> Signup and view all the answers

    What type of epithelial tissue is present in the skin?

    <p>Squamous</p> Signup and view all the answers

    What is the characteristic of pseudostratified epithelial tissue?

    <p>It appears stratified but all cells are in contact with the basement membrane.</p> Signup and view all the answers

    What is the function of the basement membrane in epithelial tissue?

    <p>To separate the epithelium from the underlying connective tissue</p> Signup and view all the answers

    What type of epithelial tissue is present in the intestines?

    <p>Columnar</p> Signup and view all the answers

    What is the function of keratin intermediate filaments in epithelial tissue?

    <p>To provide mechanical strength to the tissue</p> Signup and view all the answers

    What covers the outside of the body and invaginations of the gastrointestinal, respiratory, renal, and reproductive systems?

    <p>Epithelial tissue</p> Signup and view all the answers

    What is the primary characteristic of epithelial cells that allows them to serve structural and endocrine functions?

    <p>Specialization</p> Signup and view all the answers

    What type of filaments are present in epithelial cells?

    <p>Keratin</p> Signup and view all the answers

    What is the function of epithelial cells in the skin?

    <p>To regulate water loss</p> Signup and view all the answers

    What is the characteristic of epithelial cells that allows them to be tightly packed together?

    <p>Cell adhesion</p> Signup and view all the answers

    What is the main difference between skin and buccal epithelia?

    <p>Location</p> Signup and view all the answers

    What is the function of epithelial cells in the respiratory system?

    <p>To facilitate gas exchange</p> Signup and view all the answers

    What is the primary function of epithelial cells in the body?

    <p>To line and cover body surfaces</p> Signup and view all the answers

    What percentage of the genome consists of non-coding DNA?

    <p>98%</p> Signup and view all the answers

    What is the term for the complete set of chromosomes in a cell?

    <p>Karyotype</p> Signup and view all the answers

    What is the primary function of histone proteins?

    <p>To form chromatin with DNA</p> Signup and view all the answers

    What is the approximate number of base pairs of DNA in a human cell?

    <p>3.0 x 10^9</p> Signup and view all the answers

    What is the term for the center of a chromosome?

    <p>Centromere</p> Signup and view all the answers

    What is the term for the end of a chromosome?

    <p>Telomere</p> Signup and view all the answers

    What is the function of RNA polymerase in transcription?

    <p>To form RNA from DNA template</p> Signup and view all the answers

    What is the result of a silent mutation?

    <p>A codon that still codes for the same amino acid</p> Signup and view all the answers

    What is the genetic code?

    <p>A dictionary that links RNA sequence to an amino acid</p> Signup and view all the answers

    What is the function of microRNA?

    <p>To regulate gene expression</p> Signup and view all the answers

    What is the function of tRNA?

    <p>To bring amino acids to the ribosome during translation</p> Signup and view all the answers

    What is the result of a missense mutation?

    <p>A codon that codes for a different amino acid</p> Signup and view all the answers

    What is the function of rRNA?

    <p>To form the ribosome</p> Signup and view all the answers

    What base is present in RNA but not in DNA?

    <p>U</p> Signup and view all the answers

    What is the correct sequence of genetic information flow during cell growth and replication?

    <p>DNA → RNA → Protein</p> Signup and view all the answers

    What is the process of synthesizing RNA from DNA called?

    <p>Transcription</p> Signup and view all the answers

    What is the main difference between prokaryotes and eukaryotes in terms of gene transcription?

    <p>Eukaryotes have separate mRNA molecules for each gene, while prokaryotes have multiple genes on one mRNA</p> Signup and view all the answers

    What is the result of the central dogma?

    <p>The creation of proteins from RNA</p> Signup and view all the answers

    What is the term for the synthesis of proteins from RNA?

    <p>Translation</p> Signup and view all the answers

    What is the characteristic of RNA molecules compared to DNA molecules?

    <p>RNA molecules are shorter than DNA molecules</p> Signup and view all the answers

    What is the term for the process of creating RNA from DNA?

    <p>Transcription</p> Signup and view all the answers

    What is the result of the flow of genetic information during cell growth and replication?

    <p>The creation of gene products</p> Signup and view all the answers

    What is the primary function of the somites in embryonic development?

    <p>Development of muscle, bone and cartilage</p> Signup and view all the answers

    At what stage of development do the pharyngeal arches begin to form?

    <p>Day 22</p> Signup and view all the answers

    What is the purpose of the pharyngeal pouches in embryonic development?

    <p>Separation of the arches</p> Signup and view all the answers

    What is the relationship between the pharyngeal arches and the pharyngeal grooves?

    <p>Pharyngeal arches form on the endodermal side, while pharyngeal grooves form on the ectodermal side</p> Signup and view all the answers

    What is the characteristic of the pharyngeal arches?

    <p>Contain muscle, cartilage, and cranial nerves</p> Signup and view all the answers

    What is the significance of the hindlimb and forelimb buds in embryonic development?

    <p>They will eventually develop into the limbs</p> Signup and view all the answers

    Which of the following muscles develop from the first pharyngeal arch?

    <p>Masticatory muscles and anterior belly of digastric</p> Signup and view all the answers

    What is the origin of the cartilage and bone in the pharyngeal arches?

    <p>Neural crest cells</p> Signup and view all the answers

    Which of the following cranial nerves develop from the first pharyngeal arch?

    <p>Trigeminal nerve</p> Signup and view all the answers

    What is the result of the failure of fusion of the maxillary process and the mandibular process?

    <p>Unilateral cleft lip</p> Signup and view all the answers

    What is the name of the process by which the frontonasal process forms the nasal septum and the nasal pits?

    <p>Facial development</p> Signup and view all the answers

    Which of the following structures develop from the fourth pharyngeal arch?

    <p>Larynx</p> Signup and view all the answers

    What is the name of the process by which the palatal shelves elevate and fuse to form the hard palate?

    <p>Palate development</p> Signup and view all the answers

    What is the result of the failure of fusion of the medial nasal processes?

    <p>Median cleft lip</p> Signup and view all the answers

    Which of the following structures develop from the second pharyngeal arch?

    <p>Stapes</p> Signup and view all the answers

    What is the name of the process by which the somites develop into the muscles of the pharynx?

    <p>Somite development</p> Signup and view all the answers

    What is the approximate time frame when the mid-palatal suture ossifies?

    <p>12-14 years</p> Signup and view all the answers

    What is the ratio of males to females in the occurrence of cleft lip with cleft palate?

    <p>2:1</p> Signup and view all the answers

    What is the term for the failure of fusion of the palatal shelves with the tectal ridge?

    <p>Cleft palate</p> Signup and view all the answers

    What is the name of the type of cleft that involves the hard or soft palate, but appears intact with muscle and bone deficits?

    <p>Submucous cleft</p> Signup and view all the answers

    What is the approximate frequency of occurrence of cleft lip with cleft palate?

    <p>1 in 1600</p> Signup and view all the answers

    What is the process by which the epithelial cells undergo transformation to allow the fusion of the processes?

    <p>Epithelial mesenchymal transformation</p> Signup and view all the answers

    What is the term for the cleft that occurs anterior to the incisive foramen?

    <p>Cleft involving primary palate</p> Signup and view all the answers

    What is the ratio of males to females in the occurrence of cleft palate?

    <p>1:2</p> Signup and view all the answers

    What is the approximate time frame when the maxilla forms through intramembranous ossification?

    <p>8 weeks of intrauterine life</p> Signup and view all the answers

    What is the term for the type of cleft that occurs posterior to the incisive foramen?

    <p>Cleft involving secondary palate</p> Signup and view all the answers

    What is the primary driver of tooth eruption according to the study?

    <p>Bite forces sensed by dental follicles</p> Signup and view all the answers

    What type of analysis was used to study tooth eruption in the study?

    <p>Finite element analysis</p> Signup and view all the answers

    What is the title of the journal where the study was published?

    <p>PLoS One</p> Signup and view all the answers

    Who is the author of the study?

    <p>Prof Hans Zoellner</p> Signup and view all the answers

    What is the year of publication of the study?

    <p>2013</p> Signup and view all the answers

    What is the volume number of the journal where the study was published?

    <p>8</p> Signup and view all the answers

    What is the first stage of tooth development?

    <p>Initiation Stage</p> Signup and view all the answers

    What is the function of the dental lamina in tooth development?

    <p>It provides a pathway for the growth of the tooth</p> Signup and view all the answers

    What is the structure that forms in the Bud Stage of tooth development?

    <p>Bud</p> Signup and view all the answers

    What is the term for the structure that forms in the Early Bell Stage of tooth development?

    <p>Enamel organ</p> Signup and view all the answers

    What is the structure that forms in the Late Bell Stage of tooth development?

    <p>Cervical loop</p> Signup and view all the answers

    What is the term for the process by which the root of the tooth forms?

    <p>Root formation</p> Signup and view all the answers

    What is the term for the cells that form the dentine of the tooth?

    <p>Odontoblasts</p> Signup and view all the answers

    What is the structure that forms in the Root Formation Stage of tooth development?

    <p>Hertwig’s Epithelial Root Sheath</p> Signup and view all the answers

    What is the term for the cells that form the cementum of the tooth?

    <p>Cementoblasts</p> Signup and view all the answers

    What is the term for the cells that remain in the periodontal ligament after tooth development?

    <p>Rests of Malassez</p> Signup and view all the answers

    What forms the connection between the tooth and the surrounding bone tissue?

    <p>Periodontal Ligament</p> Signup and view all the answers

    What is the stage of tooth development where the enamel epithelium is reduced?

    <p>Late Bell Stage</p> Signup and view all the answers

    What is the term for the junction between the dentine and enamel?

    <p>Dentine-Enamel Junction (DEJ)</p> Signup and view all the answers

    What is the type of dentine that forms first?

    <p>Primary Dentine</p> Signup and view all the answers

    What is the function of the ameloblasts?

    <p>To produce enamel</p> Signup and view all the answers

    What is the term for the layer of cells that forms the outer layer of the enamel organ?

    <p>Outer Enamel Epithelium</p> Signup and view all the answers

    What is the term for the strands of collagen that form the dental lamina?

    <p>Back-Growth of Dental Lamina</p> Signup and view all the answers

    What is the name of the process by which the dental pulp is formed?

    <p>Dental Pulp Formation</p> Signup and view all the answers

    What is a characteristic of bacteria?

    <p>They have a cell wall containing peptidoglycan.</p> Signup and view all the answers

    What is an example of a disease caused by bacteria?

    <p>All of the above</p> Signup and view all the answers

    What is a characteristic of fungi?

    <p>They are a diverse group with 90,000 identified species.</p> Signup and view all the answers

    What type of organisms are Porphymonas gingivalis?

    <p>Bacteria</p> Signup and view all the answers

    What is a characteristic of prokaryotes?

    <p>They are single-celled.</p> Signup and view all the answers

    What is a common habitat of bacteria?

    <p>Ubiquitous in the environment and on humans</p> Signup and view all the answers

    What is a role of fungi in the human body?

    <p>They can cause oral thrush</p> Signup and view all the answers

    What is a characteristic of Gram-stain of coliforms?

    <p>They have parallel sides and rounded ends</p> Signup and view all the answers

    What is the percentage of worlds oxygen produced by algae and cyanobacteria?

    <p>50%</p> Signup and view all the answers

    Which of the following is a human disease caused by a protist?

    <p>Malaria</p> Signup and view all the answers

    What is the simplest form of a virus?

    <p>Protein + Nucleic acid</p> Signup and view all the answers

    What type of disease is caused by viroids?

    <p>Plant diseases</p> Signup and view all the answers

    What is the term for infectious proteins?

    <p>Prions</p> Signup and view all the answers

    Which of the following is not a characteristic of viruses?

    <p>They are living entities</p> Signup and view all the answers

    What is the main difference between archaea and bacteria?

    <p>Cell wall composition</p> Signup and view all the answers

    Why is it important to know about different microorganisms?

    <p>To understand the importance of microorganisms in the environment</p> Signup and view all the answers

    What is the first requirement of Koch's postulates?

    <p>The micro-organism must be present in every disease and absent in every health case</p> Signup and view all the answers

    What is a characteristic of Archea and Bacteria?

    <p>They are prokaryotes</p> Signup and view all the answers

    Which of the following is NOT a reservoir of microbes?

    <p>Atmosphere</p> Signup and view all the answers

    What is the characteristic that distinguishes cellular from acellular microbes?

    <p>Cellular structure</p> Signup and view all the answers

    Which of the following microorganisms can cause disease?

    <p>All of the above</p> Signup and view all the answers

    What is a function of microbes?

    <p>They make life possible</p> Signup and view all the answers

    What is an example of a zoonosis?

    <p>Rabies</p> Signup and view all the answers

    Which of the following is an example of a fungus?

    <p>Slime moulds</p> Signup and view all the answers

    What is the term for the movement of water through a semi-permeable membrane to equalize the concentration of a solution?

    <p>Osmosis</p> Signup and view all the answers

    What is the term for a microbe that can cause disease in humans?

    <p>Pathogen</p> Signup and view all the answers

    What is the definition of micro-organisms?

    <p>Organisms that are less than 1mm in diameter</p> Signup and view all the answers

    What is a characteristic of viruses?

    <p>They are acellular</p> Signup and view all the answers

    Which of the following is an example of a protist?

    <p>Algae</p> Signup and view all the answers

    Which of the following is an example of an acellular microbe?

    <p>Virus</p> Signup and view all the answers

    Who is the presenter of the introduction to microbes course?

    <p>Prof Vitali Sintchenko</p> Signup and view all the answers

    What is the main function of Koch's postulates?

    <p>To identify the cause of a disease</p> Signup and view all the answers

    What is the name of the textbook that covers bacterial morphology and nomenclature?

    <p>Eds: Joanne Willey, Linda Sherwood, Chris Woolverton</p> Signup and view all the answers

    What is one of the learning objectives of the introduction to microbes course?

    <p>To detail the different classes of micro-organisms</p> Signup and view all the answers

    What is the topic of lecture 4 in the course?

    <p>Host microbe interaction</p> Signup and view all the answers

    Why are micro-organisms important?

    <p>They are involved in human disease</p> Signup and view all the answers

    What is the name of the textbook that covers oral microbiology?

    <p>Oral Microbiology</p> Signup and view all the answers

    Who originally developed the introduction to microbes course?

    <p>Dr Christina Adler</p> Signup and view all the answers

    What is the primary function of the Linnaean naming convention?

    <p>To determine the genus and species of an organism</p> Signup and view all the answers

    What is the characteristic of Streptococcus species?

    <p>They are spherical in shape</p> Signup and view all the answers

    What is the purpose of a phylogenetic tree?

    <p>To represent the evolutionary relationships between organisms</p> Signup and view all the answers

    What is the difference between genus and species?

    <p>Species refers to a collection of strains, while genus refers to a group of species</p> Signup and view all the answers

    What is the characteristic of diplococci?

    <p>They are spherical in shape and occur in pairs</p> Signup and view all the answers

    What is the primary function of genomic similarity in bacterial classification?

    <p>To classify bacteria based on their DNA sequences</p> Signup and view all the answers

    What is the characteristic of staphylococci?

    <p>They are spherical in shape and occur in clusters</p> Signup and view all the answers

    What is the primary function of a phylogenetic tree in bacterial classification?

    <p>To represent the evolutionary relationships between bacteria</p> Signup and view all the answers

    What is the characteristic of Bacteroidetes?

    <p>Gram negative and rod shaped</p> Signup and view all the answers

    Which of the following bacteria is associated with disease?

    <p>Both A and B</p> Signup and view all the answers

    What type of bacteria does not have a cell wall?

    <p>Some bacteria</p> Signup and view all the answers

    What is the significance of Gram staining?

    <p>It is used to classify bacteria based on the composition of their cell walls</p> Signup and view all the answers

    What is the significance of the shape of bacteria?

    <p>It is used to classify bacteria based on their shape, such as rods, cocci, or spirilla</p> Signup and view all the answers

    What is the significance of respiration in bacterial classification?

    <p>It is used to classify bacteria based on their metabolic capabilities</p> Signup and view all the answers

    What is the significance of the nomenclature of bacteria?

    <p>It is used to identify and classify bacteria using a universal system</p> Signup and view all the answers

    What is the significance of historical criteria in bacterial classification?

    <p>It is used to classify bacteria based on their Gram stain reaction and shape</p> Signup and view all the answers

    What is the primary purpose of Gram staining in microbiology?

    <p>To distinguish between Gram-positive and Gram-negative bacteria</p> Signup and view all the answers

    What is the term for the spiral-shaped bacteria?

    <p>Spirochaetes</p> Signup and view all the answers

    Which of the following is an example of bacterial arrangement?

    <p>Clumps</p> Signup and view all the answers

    What is the purpose of a phylogenetic tree in microbiology?

    <p>To understand the evolutionary relationships between organisms</p> Signup and view all the answers

    Who is credited with developing the system of naming organisms?

    <p>Carl Linnaeus</p> Signup and view all the answers

    What is the term for the round or spherical bacteria?

    <p>Cocci</p> Signup and view all the answers

    Why is it important to focus on bacteria in oral health?

    <p>They are numerically the most dominant cells in the oral cavity</p> Signup and view all the answers

    What is the term for the movement of molecules from an area of higher concentration to an area of lower concentration?

    <p>Diffusion</p> Signup and view all the answers

    What type of bacteria growth is allowed by semi-solid media?

    <p>Microaerophilic</p> Signup and view all the answers

    What is the purpose of measuring optical density at 600 nm?

    <p>To quantify bacterial growth</p> Signup and view all the answers

    What is the advantage of using solid media for bacterial growth?

    <p>Allows for the isolation of single colonies</p> Signup and view all the answers

    What is the purpose of serial dilution and plating on agar?

    <p>To enumerate colony-forming units</p> Signup and view all the answers

    What is the purpose of qPCR in bacterial quantification?

    <p>To quantify bacterial growth</p> Signup and view all the answers

    What is the advantage of using liquid media for bacterial growth?

    <p>Allows for uniformed growth until nutrient limitation</p> Signup and view all the answers

    What is the primary way bacteria grow and replicate?

    <p>By binary fission</p> Signup and view all the answers

    What is the optimal temperature for bacterial growth?

    <p>37oC</p> Signup and view all the answers

    What type of bacteria requires oxygen for growth?

    <p>Strict aerobes</p> Signup and view all the answers

    What is the purpose of additives in culture media?

    <p>To enrich or inhibit certain bacteria</p> Signup and view all the answers

    What is the difference between defined and complex culture media?

    <p>Defined media has an exact composition, while complex media has an unknown composition</p> Signup and view all the answers

    What type of bacteria prefers oxygen for growth, but can grow without it?

    <p>Facultative aerobes</p> Signup and view all the answers

    What is the purpose of culture media in a laboratory?

    <p>To provide a substance that supports the growth of bacteria</p> Signup and view all the answers

    What type of bacteria cannot grow in the presence of oxygen?

    <p>Strict anaerobes</p> Signup and view all the answers

    What is the primary characteristic of the Lag phase in a bacterial growth curve?

    <p>Bacteria are adapting to new environment and replicating chromosomes</p> Signup and view all the answers

    In the oral environment, which phase corresponds to the period of fasting in between meals?

    <p>Stationary phase</p> Signup and view all the answers

    What is the primary characteristic of the Exponential phase in a bacterial growth curve?

    <p>Cells are growing and dividing maximally</p> Signup and view all the answers

    What is the primary characteristic of the Death phase in a bacterial growth curve?

    <p>Cells stop growing and die even when supplied with new medium</p> Signup and view all the answers

    In the oral environment, which phase corresponds to the period immediately after a meal?

    <p>Lag phase</p> Signup and view all the answers

    What is the primary characteristic of the Stationary phase in a bacterial growth curve?

    <p>Cell numbers stop increasing and DNA replication is arrested</p> Signup and view all the answers

    In the oral environment, which phase corresponds to the period when bacteria are susceptible to antimicrobials?

    <p>Stationary phase</p> Signup and view all the answers

    What is the primary function of the proteins produced during the Stationary phase?

    <p>To enhance cell survival during starvation</p> Signup and view all the answers

    What is the term for a state of infection that results in no damage to the host?

    <p>Commensalism</p> Signup and view all the answers

    What is the term for the collection of microorganisms that share our body space?

    <p>Microbiome</p> Signup and view all the answers

    What is the term for the relationship between two organisms where both benefit?

    <p>Mutualism</p> Signup and view all the answers

    What is the term for the acquisition of microorganisms by the host?

    <p>Colonization</p> Signup and view all the answers

    What is the term for an organism that consists of a host and its microbiome?

    <p>Holobiont</p> Signup and view all the answers

    Why are commensal microorganisms beneficial to humans?

    <p>They protect us from foreign substances and pathogens</p> Signup and view all the answers

    What is the approximate ratio of microbial cells to human cells in the human body?

    <p>10^4:10^3</p> Signup and view all the answers

    Where are commensal microorganisms typically found in the human body?

    <p>Skin, oral, respiratory, and gastrointestinal tracts</p> Signup and view all the answers

    What is the primary function of the human microbiome?

    <p>To protect the host against pathogens and provide nutrients</p> Signup and view all the answers

    What is unique about the 16S ribosomal RNA sequencing?

    <p>It has a slow rate of evolution and is highly-conserved between bacteria and archaea</p> Signup and view all the answers

    What is the difference between culture-dependent and culture-independent methods?

    <p>Culture-dependent methods require culturing, while culture-independent methods do not</p> Signup and view all the answers

    What is the goal of shotgun metagenomics?

    <p>To sequence every nucleic acid within a given sample</p> Signup and view all the answers

    What is a characteristic of the human microbiome?

    <p>It has a huge diversity in composition</p> Signup and view all the answers

    What is a limitation of traditional microbiology techniques?

    <p>Most microorganisms cannot be cultured</p> Signup and view all the answers

    What can metagenomics be used for?

    <p>Insights into population dynamics</p> Signup and view all the answers

    What is a characteristic of the skin microbiota?

    <p>High salt content</p> Signup and view all the answers

    What is a function of bacteria on the skin?

    <p>Producing body odour</p> Signup and view all the answers

    Where can metagenomics be applied?

    <p>Host microbiome</p> Signup and view all the answers

    What can be characterised using metagenomics?

    <p>All of the above</p> Signup and view all the answers

    What is the environment like on the superficial skin?

    <p>Slightly acidic</p> Signup and view all the answers

    What is the term used to describe the relationship between humans and microbes?

    <p>Holobionts</p> Signup and view all the answers

    What is the effect of the microbiome on caloric absorption in mice?

    <p>Increases caloric absorption</p> Signup and view all the answers

    What is an example of a disease caused by microbiome dysbiosis?

    <p>All of the above</p> Signup and view all the answers

    What is the term used to describe the state of the microbiome when it is out of balance?

    <p>Dysbiosis</p> Signup and view all the answers

    What is the characteristic of the microbiome across the human body?

    <p>It is diverse and in flux</p> Signup and view all the answers

    What is the effect of a germ-free diet on mice?

    <p>They gain less weight</p> Signup and view all the answers

    What is the role of microbes in the body?

    <p>They can be either beneficial or harmful</p> Signup and view all the answers

    What is the term used to describe the relationship between the microbiome and fat storage?

    <p>Environmental factor</p> Signup and view all the answers

    In which part of the gut does the highest diversity of microbiota exist?

    <p>Large intestine</p> Signup and view all the answers

    What is one of the symbiotic relationships of the gut microbiota?

    <p>Produce biotin and vitamin K</p> Signup and view all the answers

    What is a characteristic of the oral microbiota after tooth eruption?

    <p>Increase in anaerobes</p> Signup and view all the answers

    What is the relationship between the oral microbiota and taste perception?

    <p>The oral microbiota alters taste perception</p> Signup and view all the answers

    What is the result of changes to the oral microbiota on human health?

    <p>Decreased blood pressure</p> Signup and view all the answers

    What is the characteristic of the stomach microbiota?

    <p>Highly acidic with few viable bacteria</p> Signup and view all the answers

    What is the role of the gut microbiota in preventing pathogen colonization?

    <p>They compete with pathogens for nutrients</p> Signup and view all the answers

    What is the characteristic of the small intestine microbiota?

    <p>Highly acidic with few viable bacteria</p> Signup and view all the answers

    What is the term used to describe the symbiotic relationship between humans and microorganisms?

    <p>Holobiont</p> Signup and view all the answers

    What is the main characteristic of the stomach in terms of gut microbiota?

    <p>Highly acidic with few viable bacteria</p> Signup and view all the answers

    Which of the following is an example of dysbiosis?

    <p>All of the above</p> Signup and view all the answers

    What is the role of the gut microbiota in the large intestine?

    <p>To prevent pathogens from colonizing and absorb nutrients</p> Signup and view all the answers

    What is the factor that regulates fat storage, according to Bäckhed et al.?

    <p>Microbiota</p> Signup and view all the answers

    When does the mouth become colonized with microbiota?

    <p>Soon after birth</p> Signup and view all the answers

    Which of the following is NOT a characteristic of the microbiome?

    <p>Constant and unchanging</p> Signup and view all the answers

    What is the role of the oral microbiota in taste perception?

    <p>To alter taste perception</p> Signup and view all the answers

    What is the result of having a germ-free (GF) versus conventional mice, when fed the same diet?

    <p>GF mice gain less weight</p> Signup and view all the answers

    What is the term used to describe the state of balance and stability in the body's internal environment?

    <p>Homeostasis</p> Signup and view all the answers

    What is the characteristic of the small intestine in terms of gut microbiota?

    <p>Acidic with bile juices and few viable bacteria</p> Signup and view all the answers

    What is the term used to describe the community of microorganisms that inhabit the human body?

    <p>Microbiome</p> Signup and view all the answers

    What is the role of the gut microbiota in the large intestine?

    <p>To prevent pathogens from colonizing and absorb nutrients</p> Signup and view all the answers

    What is the characteristic of the large intestine in terms of gut microbiota?

    <p>Highly diverse with 10^12 cells/gram stool</p> Signup and view all the answers

    What is an example of a dental condition caused by microbiome dysbiosis?

    <p>All of the above</p> Signup and view all the answers

    What is the result of changes to the oral microbiota?

    <p>Modulation of nitric oxide homeostasis and blood pressure</p> Signup and view all the answers

    What is the term for the state of infection that results in no damage to the host?

    <p>Commensalism</p> Signup and view all the answers

    What is the term for the collection of microorganisms that live within and on the human body?

    <p>Microbiome</p> Signup and view all the answers

    What is the term for the relationship between the host and microbe where both benefit?

    <p>Mutualism</p> Signup and view all the answers

    What is the approximate ratio of microbial cells to human cells in the human body?

    <p>10^14:10^13</p> Signup and view all the answers

    What is the term for the acquisition of micro-organisms by the host?

    <p>Colonization</p> Signup and view all the answers

    What is the term for the beneficial tasks performed by the microbiome?

    <p>Protection from foreign substances and pathogens</p> Signup and view all the answers

    What is the term for the collection of microbial cells that live on the skin and in the oral, respiratory and gastrointestinal tracts?

    <p>Commensals</p> Signup and view all the answers

    What is the term for the host and its associated microbiome?

    <p>Holobiont</p> Signup and view all the answers

    What can metagenomics be used for?

    <p>Insights into population dynamics</p> Signup and view all the answers

    What characterizes the environment on superficial skin?

    <p>High salt, low water content, and inhibitory substances</p> Signup and view all the answers

    What is a result of bacterial degradation of skin oil?

    <p>Body odor</p> Signup and view all the answers

    What can be characterized through the use of metagenomics?

    <p>Microbial communities, including DNA and/or RNA from bacteria, viruses, fungi, and the host</p> Signup and view all the answers

    What is a feature of the respiratory microbiota?

    <p>High bacterial diversity in the lungs</p> Signup and view all the answers

    What can be analyzed through metagenomics?

    <p>Extended characterization of the microbial community, including subtyping, AMR genes, and virulence genes</p> Signup and view all the answers

    What is one of the functions of the microbiome?

    <p>To protect the host against pathogens</p> Signup and view all the answers

    What is characteristic of the 16S rRNA gene?

    <p>It is highly conserved between bacteria and archaea</p> Signup and view all the answers

    What is the main difference between culturable and non-culturable microorganisms?

    <p>Culturable microorganisms can be grown on a petri dish, while non-culturable microorganisms cannot</p> Signup and view all the answers

    What is shotgun metagenomics?

    <p>A method for sequencing every nucleic acid within a given sample</p> Signup and view all the answers

    What is the main advantage of using culture-independent methods in microbiome research?

    <p>They provide a more accurate view of microbial diversity</p> Signup and view all the answers

    At what stage of life is the microbiome typically acquired?

    <p>During the first year of life</p> Signup and view all the answers

    What is a common early coloniser in dental plaque?

    <p>Streptococci</p> Signup and view all the answers

    What is a disadvantage of living in a biofilm?

    <p>Slower diffusion of nutrients</p> Signup and view all the answers

    What is a mechanism by which bacteria exchange DNA to tolerate acidic conditions?

    <p>Horizontal gene transfer</p> Signup and view all the answers

    What is a protein toxin produced by bacteria that can help prevent URT infections?

    <p>Bacteriocins</p> Signup and view all the answers

    Why do chemicals tend to concentrate in biofilms?

    <p>Due to the structure of the biofilm</p> Signup and view all the answers

    What is a characteristic of bacteria that produce bacteriocins?

    <p>They produce narrow-spectrum antimicrobial proteins</p> Signup and view all the answers

    What is an advantage of living in a biofilm?

    <p>Increased resistance to environmental stress</p> Signup and view all the answers

    What is the physiology of the oral biofilm a reflection of?

    <p>The activity of the entire microbial community</p> Signup and view all the answers

    At six months, what is the significant event that influences the oral microbiome?

    <p>Tooth emergence</p> Signup and view all the answers

    What is the primary advantage of biofilm formation in the oral cavity?

    <p>Increased diversity of nutrients for the microbial community</p> Signup and view all the answers

    Which bacteria are increasingly abundant during the period of tooth emergence?

    <p>Fusobacterium, Lactobacillus, Neissera, Gemella, and Haemophillius</p> Signup and view all the answers

    What is the primary factor influencing the development of the oral microbiome during childhood?

    <p>Postnatal factors</p> Signup and view all the answers

    What is the result of an imbalance in the oral microbiome during childhood?

    <p>All of the above</p> Signup and view all the answers

    What is the primary role of the oral microbiome in maintaining oral health?

    <p>Maintaining a balance of commensal bacteria</p> Signup and view all the answers

    What is the primary source of bacteria in the infant oral microbiome during the first 6 months?

    <p>Precolostrum from mothers</p> Signup and view all the answers

    What is the effect of breastfeeding on the oral microbiome of infants?

    <p>Increases the abundance of Veillonella species</p> Signup and view all the answers

    What is the primary advantage of living in a biofilm for oral microorganisms?

    <p>Enhanced adherence to oral surfaces</p> Signup and view all the answers

    What is the primary factor influencing the development of the oral microbiome during early childhood?

    <p>Early feeding practices</p> Signup and view all the answers

    What is the primary role of Streptococcus species in the oral microbiome?

    <p>Production of lactate</p> Signup and view all the answers

    What is the primary mechanism of antibiotic resistance in oral biofilms?

    <p>Biofilm-mediated protection</p> Signup and view all the answers

    What is the primary consequence of an imbalance in the oral microbiome?

    <p>Increased susceptibility to oral infections</p> Signup and view all the answers

    What is the primary function of Veillonella species in the oral microbiome?

    <p>Utilization of lactate</p> Signup and view all the answers

    What is the primary function of neutrophils in the immune system?

    <p>To kill bacteria and make pus</p> Signup and view all the answers

    What is the process called when phagocytic cells move towards the source of bacterial products?

    <p>Chemotaxis</p> Signup and view all the answers

    What is the role of the complement system in phagocytosis?

    <p>To coat microorganisms for recognition by phagocytic cells</p> Signup and view all the answers

    What is the term for the coating of microorganisms to facilitate phagocytosis?

    <p>Opsonization</p> Signup and view all the answers

    What is the role of Toll-like receptors in immunity?

    <p>To recognize bacterial products</p> Signup and view all the answers

    What is the primary function of Eosinophils?

    <p>To contribute to allergy</p> Signup and view all the answers

    What is the process called when neutrophils move towards the source of bacterial products?

    <p>Chemotaxis</p> Signup and view all the answers

    What is the term for the sugar polymer that is a component of the bacterial cell wall?

    <p>Peptidoglycan</p> Signup and view all the answers

    What is the primary function of phagocytosis?

    <p>To capture and digest foreign particles</p> Signup and view all the answers

    What is the role of opsonins in the immune system?

    <p>To attach to microbes and increase phagocytosis</p> Signup and view all the answers

    What is the function of chemokines in the immune system?

    <p>To attract macrophages and neutrophils to infected tissues</p> Signup and view all the answers

    What is the result of defective neutrophil function?

    <p>Microbial accumulation and inflammation</p> Signup and view all the answers

    Which of the following cells primarily produce myeloperoxidase?

    <p>Neutrophils, monocytes, and macrophages</p> Signup and view all the answers

    What is the term for the process by which cells take in material from outside the cell?

    <p>Phagocytosis</p> Signup and view all the answers

    What is the primary function of the oxygen-independent pathway in phagocytosis?

    <p>Degradation of ingested pathogens using lysosomal enzymes</p> Signup and view all the answers

    Which type of cell is responsible for presenting antigens to T-cells?

    <p>All of the above</p> Signup and view all the answers

    What is the primary function of chemokines in the immune response?

    <p>Recruitment of immune cells to the site of infection</p> Signup and view all the answers

    Which toxin produced by Porphyromonas gingivalis corrupts adhesion complexes, allowing access of microbial products to the underlying tissue?

    <p>Toxin with structural similarity to intercellular adhesion molecules</p> Signup and view all the answers

    What is the primary function of neutrophils in the immune response?

    <p>Phagocytosis and killing of microbes</p> Signup and view all the answers

    What is the result of activating toll-like receptors (TLRs) in the immune response?

    <p>Production of cytokines and activation of immune responses</p> Signup and view all the answers

    What type of antigens do MHC class I molecules display?

    <p>Self-antigens</p> Signup and view all the answers

    What is the primary function of MHC class I and II molecules?

    <p>Presenting antigens to T-cells</p> Signup and view all the answers

    Which type of immune response involves the activation of T-cells that recognize antigens displayed on MHC molecules?

    <p>Adaptive immune response</p> Signup and view all the answers

    What is the role of CD28 in T-cell activation?

    <p>It provides co-stimulation to T-cells</p> Signup and view all the answers

    What is the primary function of CTLA-4 in T-cell activation?

    <p>It limits T-cell expansion</p> Signup and view all the answers

    What is the role of IL-2 in T-cell activation?

    <p>It promotes T-cell proliferation</p> Signup and view all the answers

    What determines the specificity of adaptive immune responses?

    <p>Recognition of specific epitopes</p> Signup and view all the answers

    What is the primary function of dendritic cells in adaptive immunity?

    <p>Presentation of antigens to T-cells</p> Signup and view all the answers

    What is the primary function of dendritic cells in the immune response?

    <p>To process and present antigens to T-cells</p> Signup and view all the answers

    What is the main difference between MHC Class I and MHC Class II?

    <p>MHC Class I is expressed on all nucleated cells, while MHC Class II is expressed only on antigen-presenting cells</p> Signup and view all the answers

    What is the primary function of the innate immune response?

    <p>To reduce the pathogen load and prevent infection</p> Signup and view all the answers

    What is the role of antigen-presenting cells in the adaptive immune response?

    <p>To process and present antigens to T-cells</p> Signup and view all the answers

    What is the main characteristic of acquired immunity?

    <p>Provides long-term immunity against specific pathogens</p> Signup and view all the answers

    What is the role of MHC molecules in antigen presentation?

    <p>To present antigens to T-cells</p> Signup and view all the answers

    What type of antigens require T cell 'help'?

    <p>Soluble proteins</p> Signup and view all the answers

    What is the primary function of adaptive immunity?

    <p>To provide long-term immunity against specific pathogens</p> Signup and view all the answers

    What is unique about B cell receptors (BCRs)?

    <p>They recognize antigens in their native unprocessed forms</p> Signup and view all the answers

    What is the role of dendritic cells in the initiation of the adaptive immune response?

    <p>To process and present antigens to T-cells</p> Signup and view all the answers

    What is the result of mass apoptosis of lymphocytes in the absence of antigen presentation?

    <p>Self-limitation</p> Signup and view all the answers

    What is the function of CD40 in antigen recognition?

    <p>Costimulatory molecule</p> Signup and view all the answers

    What type of antibodies are produced by B1 cells?

    <p>IgM</p> Signup and view all the answers

    What is the result of affinity maturation?

    <p>Decrease in the dissociation constant (Kd)</p> Signup and view all the answers

    What is the primary function of the muscles of facial expression?

    <p>To allow for facial movements and expressions</p> Signup and view all the answers

    Which bone makes up the majority of the skull?

    <p>Cranial bone</p> Signup and view all the answers

    What is the primary function of the trigeminal nerve in the head and neck?

    <p>To enable sensation in the face and head</p> Signup and view all the answers

    What is the term for the joint that connects the mandible to the skull?

    <p>Temporomandibular joint (TMJ)</p> Signup and view all the answers

    What is the primary function of the muscles of mastication?

    <p>To facilitate the movement of the jaw for eating and speaking</p> Signup and view all the answers

    What is the term for the study of the structure and organization of the nervous system?

    <p>Neuroanatomy</p> Signup and view all the answers

    What is the primary function of the salivary glands in the head and neck?

    <p>To produce saliva for digestion and oral health</p> Signup and view all the answers

    What is the term for the anatomical landmarks of the oral cavity relevant to local anesthesia?

    <p>Anatomical landmarks for local anesthesia</p> Signup and view all the answers

    What is the primary aim of the Head and Neck Anatomy course for Oral Health Therapists?

    <p>To understand the anatomy of the head and neck</p> Signup and view all the answers

    Why do Oral Health Therapists need to know anatomy?

    <p>To understand the anatomy of the head and neck</p> Signup and view all the answers

    What is the significance of the lithograph from Joseph Maclise’s “The circulatory system” (1844)?

    <p>It shows the anatomy of the circulatory system</p> Signup and view all the answers

    Who presented the lecture on Head and Neck Anatomy?

    <p>Dr Filip Vujovic DDS, PhD</p> Signup and view all the answers

    What is the topic of the lecture presented by Dr Filip Vujovic DDS, PhD?

    <p>Anatomy of the Head and Neck</p> Signup and view all the answers

    What is the main goal of the Head and Neck Anatomy course?

    <p>To understand the anatomy of the head and neck</p> Signup and view all the answers

    Which of the following is NOT a topic covered in the Head and Neck Anatomy course?

    <p>Anatomy of the limbs</p> Signup and view all the answers

    What is the significance of the Copyright Regulation WARNING?

    <p>It indicates that the material is protected by copyright</p> Signup and view all the answers

    What is the term for the movement of the head towards the shoulder?

    <p>Lateral flexion</p> Signup and view all the answers

    What is the term for the movement of the jaw superiorly or inferiorly?

    <p>Elevation and depression</p> Signup and view all the answers

    What is the movement of the head away from the midline called?

    <p>Abduction</p> Signup and view all the answers

    What is the term for the movement of the jaw forward and backward?

    <p>Protraction and retraction</p> Signup and view all the answers

    What is the term for the movement of the head to one side, away from the midline?

    <p>Rotation</p> Signup and view all the answers

    What is the term for the movement of a body part towards the midline?

    <p>Adduction</p> Signup and view all the answers

    What is the function of the lingual papilla on the dorsal surface of the tongue?

    <p>Taste buds</p> Signup and view all the answers

    Which muscle deviates the tongue to the side and pulls the tip downwards?

    <p>Inferior longitudinal muscle</p> Signup and view all the answers

    What is the term for the folds of mucous membrane on the ventral surface of the tongue?

    <p>Fimbriated folds</p> Signup and view all the answers

    Which extrinsic tongue muscle lifts the tongue upwards?

    <p>Palatoglossus</p> Signup and view all the answers

    What is the name of the groove on the dorsal surface of the tongue that separates the oral and pharyngeal parts?

    <p>Sulcus terminalis</p> Signup and view all the answers

    Which part of the tongue is firmly attached to the hyoid bone via the genioglossus and geniohyoid muscles?

    <p>Root</p> Signup and view all the answers

    What is the name of the bony structure that forms the hard palate?

    <p>Palatine bone</p> Signup and view all the answers

    Which intrinsic tongue muscle narrows the tongue and pulls it towards the floor of the mouth?

    <p>Transverse muscle</p> Signup and view all the answers

    What is the term for the mucous membrane on the ventral surface of the tongue?

    <p>Oral mucosa</p> Signup and view all the answers

    Which extrinsic tongue muscle protrudes the tongue and moves it from side to side?

    <p>Genioglossus</p> Signup and view all the answers

    What is the main function of the tensor palati muscle?

    <p>Tightens the palate and pulls the auditory tube open</p> Signup and view all the answers

    What is the palatine aponeurosis?

    <p>A thin, firm, fibrous sheet formed by the expanded tendon of the tensor palati muscle</p> Signup and view all the answers

    What type of tissues are found in the soft palate?

    <p>Muscles, aponeuroses, and fat</p> Signup and view all the answers

    How many paired palatal muscles are there?

    <p>5</p> Signup and view all the answers

    What is the function of the levator palati muscle?

    <p>Lifts the palate up and back</p> Signup and view all the answers

    Which of the following muscles is NOT a palatal muscle?

    <p>Genioglossus</p> Signup and view all the answers

    What is the function of the orbicularis oris muscle?

    <p>To move the lips during speech</p> Signup and view all the answers

    Which of the following bones forms the cheek?

    <p>All of the above</p> Signup and view all the answers

    What is the name of the fold that forms the lips?

    <p>Musculo-fibrous fold</p> Signup and view all the answers

    What is the function of the buccinator muscle?

    <p>To compress the cheek against the teeth</p> Signup and view all the answers

    What is the colour of the gingiva?

    <p>Light coral pink to heavily pigmented</p> Signup and view all the answers

    What is the name of the gland located in the cheek?

    <p>Parotid gland</p> Signup and view all the answers

    What is the name of the zone where the lip skin meets the mucous membrane?

    <p>Vermillion</p> Signup and view all the answers

    What is the function of the masseter muscle?

    <p>To elevate the mandible during eating</p> Signup and view all the answers

    What is the name of the arch that forms the posterior border of the oral cavity proper?

    <p>Palatopharyngeal arch</p> Signup and view all the answers

    What is the function of the gingiva?

    <p>To cover the alveolar processes of the maxilla and mandible</p> Signup and view all the answers

    What is the term for the depression in the sphenoid bone that accommodates the pituitary gland?

    <p>Hypophyseal fossa</p> Signup and view all the answers

    Which of the following bones forms the floor of the posterior cranial fossa?

    <p>Occipital bone</p> Signup and view all the answers

    What is the function of the pterygoid plates?

    <p>Muscle attachment</p> Signup and view all the answers

    Which of the following features is NOT associated with the sphenoid bone?

    <p>Mandible</p> Signup and view all the answers

    What is the term for the region formed by the occipital bone and petrous temporal bone?

    <p>Posterior cranial fossa</p> Signup and view all the answers

    What is the term for the bony structure that extends from the sphenoid bone to the basilar process of the occipital bone?

    <p>Clivus</p> Signup and view all the answers

    What is the type of joint that connects most of the bones in the skull?

    <p>Fibrous joint</p> Signup and view all the answers

    Which of the following bones is NOT a part of the facial skull?

    <p>Occipital</p> Signup and view all the answers

    What is the term for the bony extensions from the body of a bone that articulate with other cranial bones or serve as attachments for muscles or ligaments?

    <p>Processes</p> Signup and view all the answers

    How many bones form the skull?

    <p>22</p> Signup and view all the answers

    What is the term for a bony bump or elevation overlying a deep structure?

    <p>Eminence</p> Signup and view all the answers

    Which of the following bones is paired?

    <p>Maxilla</p> Signup and view all the answers

    What is the name of the joint that is an exception to the non-moveable suture joints?

    <p>Temporomandibular Joint (TMJ)</p> Signup and view all the answers

    Which of the following bones is single?

    <p>Vomer</p> Signup and view all the answers

    What is the primary function of the intervertebral disc in the vertebral spine?

    <p>To reduce stress of impact and allow movement</p> Signup and view all the answers

    Which of the following bones forms the floor of the anterior cranial fossa?

    <p>Frontal bone</p> Signup and view all the answers

    What is the function of the cribriform plate in the ethmoid bone?

    <p>To transmit olfactory nerve filaments</p> Signup and view all the answers

    What is the name of the bony crest that projects superiorly from the cribriform plate in the ethmoid bone?

    <p>Crista galli</p> Signup and view all the answers

    Which of the following cranial fossae contains the pituitary gland?

    <p>Middle cranial fossa</p> Signup and view all the answers

    Which of the following bones forms the posterior boundary of the middle cranial fossa?

    <p>Petrous temporal bone</p> Signup and view all the answers

    What is the function of the ethmoidal air cells in the ethmoid bone?

    <p>To produce mucus in the nasal cavity</p> Signup and view all the answers

    Which of the following cranial bones forms the roof of the cranium?

    <p>Calvarium</p> Signup and view all the answers

    What forms the dorsum and apex of the nose?

    <p>Three main cartilages</p> Signup and view all the answers

    What are the nasal bones?

    <p>Paired, thin, and form the roof of the nasal cavity</p> Signup and view all the answers

    How many bones form the floor, roof, and lateral wall of the nasal cavity?

    <p>8 bones</p> Signup and view all the answers

    What is the composition of the nasal septum?

    <p>Cartilaginous anteriorly and bony posteriorly</p> Signup and view all the answers

    What is the location of the alveolar process with teeth?

    <p>In the oral cavity</p> Signup and view all the answers

    What is the root of the nose formed by?

    <p>Three bones</p> Signup and view all the answers

    Which of the following bones make up the nasal cavity?

    <p>Nasal, Vomer, and Concha</p> Signup and view all the answers

    Which of the following bones are part of the orbit?

    <p>Zygomatic, Maxillary, and Lacrimal bones</p> Signup and view all the answers

    Which of the following bones make up the oral cavity?

    <p>Maxilla, Mandible, and Palatine bone</p> Signup and view all the answers

    Which of the following bones is NOT a part of the facial skeleton?

    <p>Occipital bone</p> Signup and view all the answers

    What is the name of the bone that forms the floor of the orbit?

    <p>Maxillary bone</p> Signup and view all the answers

    Which of the following bones is responsible for forming the nasal septum?

    <p>Vomer bone</p> Signup and view all the answers

    Which of the following bones is NOT a part of the paranasal sinuses?

    <p>Mandible bone</p> Signup and view all the answers

    What is the name of the bone that forms the roof of the nasal cavity?

    <p>Frontal bone</p> Signup and view all the answers

    What is the primary function of the zygomatic bone in the facial structure?

    <p>Forming the infraorbital margin</p> Signup and view all the answers

    Which of the following bones forms the medial wall of the orbit?

    <p>Lacrimal bone</p> Signup and view all the answers

    What is the name of the process by which the maxilla bone articulates with other bones in the face?

    <p>Articulation</p> Signup and view all the answers

    Which of the following bones is NOT a part of the nasal cavity?

    <p>Mandible</p> Signup and view all the answers

    What is the name of the bony structure that forms the inferior margin of the orbit?

    <p>Infraorbital margin</p> Signup and view all the answers

    Which of the following bones contributes to the formation of the oral cavity?

    <p>Mandible</p> Signup and view all the answers

    What is the term for the bony structure that forms the superior and middle nasal conchae?

    <p>Ethmoid bone</p> Signup and view all the answers

    Which of the following bones is a paired bone that forms the lateral wall of the orbit?

    <p>Zygomatic bone</p> Signup and view all the answers

    Which of the following muscles is responsible for facial expression of sadness?

    <p>Depressor anguli oris</p> Signup and view all the answers

    Which of the following is NOT a levator muscle of the face?

    <p>Buccinator</p> Signup and view all the answers

    What is the origin of the zygomaticus major muscle?

    <p>Zygomatic bone</p> Signup and view all the answers

    Which of the following muscles is involved in the action of frowning?

    <p>Procerus</p> Signup and view all the answers

    What is the insertion of the levator labii superioris muscle?

    <p>Skin and muscles of the upper lip</p> Signup and view all the answers

    Which of the following facial movements is NOT a function of the buccinator muscle?

    <p>Elevation of the corner of the mouth</p> Signup and view all the answers

    What is the primary function of the muscles of facial expression?

    <p>Facilitating speech and facial expressions</p> Signup and view all the answers

    What is the characteristic of muscles of facial expression in terms of their origin and insertion?

    <p>They originate from bone and insert into skin</p> Signup and view all the answers

    Which of the following muscles are involved in facial expression?

    <p>Scalp/forehead/eyebrows muscles</p> Signup and view all the answers

    What is the type of muscle that makes up the muscles of facial expression?

    <p>Skeletal muscle</p> Signup and view all the answers

    Which of the following is NOT a category of muscles in the head and neck region?

    <p>Intercostal</p> Signup and view all the answers

    What is the primary function of the muscles of the eyes in facial expression?

    <p>Creating facial expressions</p> Signup and view all the answers

    Which muscle is responsible for the action of frowning?

    <p>Procerus</p> Signup and view all the answers

    Which of the following muscles is NOT a paired muscle of facial expression?

    <p>Orbicularis oris</p> Signup and view all the answers

    What is the origin of the frontal belly of the occipitofrontalis muscle?

    <p>Epicranial aponeurosis</p> Signup and view all the answers

    What is the action of the occipitofrontalis muscle?

    <p>Surprise</p> Signup and view all the answers

    Which muscle is responsible for the action of raising the eyebrows?

    <p>Frontal belly of occipitofrontalis</p> Signup and view all the answers

    What is the insertion of the corrugator supercilli muscle?

    <p>Skin of the eyebrow</p> Signup and view all the answers

    Which muscle is responsible for the action of depressing the eyebrows?

    <p>Procerus</p> Signup and view all the answers

    What is the function of the epicranial aponeurosis?

    <p>It forms the third layer of the scalp</p> Signup and view all the answers

    Which muscle is responsible for rotating the head to the opposite side?

    <p>Sternocleidomastoid</p> Signup and view all the answers

    What is the name of the triangle bounded by the sternocleidomastoid muscle, the trapezius muscle, and the clavicle?

    <p>Posterior triangle</p> Signup and view all the answers

    Which bone forms the lower jaw?

    <p>Mandible</p> Signup and view all the answers

    What is the function of the digastric muscle?

    <p>Elevation of the hyoid bone</p> Signup and view all the answers

    Which muscle is responsible for scapular rotation?

    <p>Trapezius</p> Signup and view all the answers

    What is the name of the muscle that originates from the mastoid process and inserts into the occipital bone?

    <p>Sternocleidomastoid</p> Signup and view all the answers

    Which muscle is responsible for elevating the hyoid bone and the floor of the mouth?

    <p>Digastric</p> Signup and view all the answers

    Which triangle is bounded by the posterior border of the sternocleidomastoid muscle and the anterior border of the trapezius muscle?

    <p>Occipital triangle</p> Signup and view all the answers

    Which muscle does not belong to the infrahyoid muscles group?

    <p>Mylohyoid</p> Signup and view all the answers

    What is the primary function of the Sternocleidomastoid muscle?

    <p>To tilt and rotate the head</p> Signup and view all the answers

    What is the location of the splenius capitus muscle?

    <p>Floor of the posterior triangle</p> Signup and view all the answers

    What are the Triangles of the Neck used to describe?

    <p>The location of key features in the neck</p> Signup and view all the answers

    Which of the following muscles is not a suprahyoid muscle?

    <p>Thyrohyoid</p> Signup and view all the answers

    What is the main function of the trapezius muscle?

    <p>To elevate the scapula</p> Signup and view all the answers

    What is the name of the bone that the Sternocleidomastoid muscle attaches to?

    <p>Mastoid process</p> Signup and view all the answers

    What is the function of the Trapezius muscle?

    <p>To move the shoulder and scapula</p> Signup and view all the answers

    Which muscle forms the border between the anterior and posterior triangles of the neck?

    <p>Sternocleidomastoid</p> Signup and view all the answers

    Which of the following muscles is not a muscle of the posterior triangle?

    <p>Digastric</p> Signup and view all the answers

    Which of the following muscles is not involved in the movement of the mandible?

    <p>Sternocleidomastoid</p> Signup and view all the answers

    What is the location of the infrahyoid muscles?

    <p>Inferior surface of the hyoid bone</p> Signup and view all the answers

    What is the name of the muscle that attaches to the ligamentum nuchae?

    <p>Trapezius</p> Signup and view all the answers

    Which muscle is responsible for elevating the hyoid bone?

    <p>Mylohyoid</p> Signup and view all the answers

    What is the location of the Parotid duct?

    <p>Lateral to the mandible</p> Signup and view all the answers

    What is the name of the muscle that attaches to the external occipital protuberance?

    <p>Trapezius</p> Signup and view all the answers

    Study Notes

    Biological Membranes

    • Biological membranes are barriers that control the movement of substances into and out of cells
    • They regulate the composition within individual cells and control the flow of information between cells
    • Membranes capture and release energy, are involved in cell adhesion, and synthesize steroids

    Structure and Function of Plasma Membrane

    • Plasma membrane is a bi-layer of phospholipids with a phosphate group (head) and two chains of fatty acids (lipid tails)
    • The head is hydrophilic (water-loving) and the tail is hydrophobic (water-fearing), making the membrane amphipathic
    • The membrane is selectively permeable, allowing some molecules to pass through while keeping others out
    • It is permeable to lipid-soluble substances (e.g., O2) and impermeable to charged molecules (e.g., ions)

    Body Fluid Balance and Distribution

    • The movement of water in the body needs to be controlled to prevent swelling and dehydration
    • Body fluids are distributed among intracellular fluid (~25 L), interstitial fluid (~12 L), plasma (~3 L), and extracellular fluid (ECF = plasma + interstitial fluid)

    Osmosis and Water Movement

    • Osmosis is the movement of water through a semi-permeable membrane to equalize the concentration of a solution
    • Osmotic pressure (OP) is created by a concentration difference of dissolved substances between two sides of a bio-membrane
    • Hydrostatic pressure can stop the movement of water
    • The size of solute particles does not influence osmosis

    Transport Across Biological Membranes

    • Passive movement follows the concentration gradient and does not require energy
    • Active transport moves substances against the concentration gradient and requires energy
    • Diffusion and facilitated diffusion are types of passive movement
    • Carrier proteins and pumps are involved in active transport

    Membrane Transport Proteins

    • Channels allow passive movement of solutes through the membrane
    • Aquaporins are small integral membrane proteins that form pores for water movement by osmosis
    • Pumps catalyze the hydrolysis of ATP to ADP and use energy for active transport
    • Carriers/transporters bind specific molecules and transfer them across the membrane

    Cellular Transport

    • Exocytosis is the process of exporting material from the cell through vesicles
    • Endocytosis is the reverse of exocytosis, taking in material into the cell
    • White blood cells use endocytosis to engulf bacteria and viruses

    Osmosis and Fluid Balance

    • Isotonic solutions have the same concentration of dissolved substances as the cell interior
    • Hypotonic solutions have a lower concentration of dissolved substances than the cell interior, causing water to move into the cell
    • Hypertonic solutions have a higher concentration of dissolved substances than the cell interior, causing water to move out of the cell
    • Osmosis is important in intravenous fluid therapy to maintain body fluid and electrolyte balance

    Intercellular Signaling

    • Cells need receptors and signaling systems to respond to changes in their immediate environment, communicate with other cells, and coordinate cellular functions.
    • Intercellular signaling involves communication between cells, while intracellular signaling occurs within cells, responding to extracellular and intracellular stimuli.

    Types of Signaling

    • Direct Signaling: Direct cell-to-cell signaling through gap junctions, allowing electrical signal transduction and the transfer of ions or small molecules between cells.
    • Chemical Signaling: Signaling by secreted molecules, including:
      • Endocrine Signaling: Hormones produced by endocrine glands, traveling through the bloodstream to distant cells, and received by surface or intracellular receptors.
      • Paracrine Signaling: Signals similar to hormones, but not entering the bloodstream, and traveling to nearby cells, with the gradient of signal molecules determining the outcome.
      • Autocrine Signaling: Signal molecules secreted by the target cell, such as prostaglandins, with the key difference being that the target cell is also the signaling cell.

    Gap Junctions

    • Allow direct communication between cells through the transfer of ions or small molecules.
    • Composed of connexons, which are transmembrane proteins forming a 3 nm thin hydrophilic channel.
    • Facilitate direct communication between cells, enabling the transfer of signaling molecules such as ATP, cAMP, IP3, Na+, K+, and Ca2+.

    Second Messengers

    • Produced in response to signal binding, causing a cellular response.
    • Some signals can cross the membrane and bind to receptors in the cytoplasm.

    Coagulation Cascade

    • A series of enzyme reactions that lead to the formation of a blood clot, involving plasma proteinase cascades
    • Types of cascades: Coagulation (forms fibrin), Fibrinolytic (degrades fibrin), Complement (inflammation), Kinin (inflammation)

    Blood Functions

    • Delivers plasma-borne substances to tissues
    • Removes waste, delivers oxygen, and carries heat
    • Delivers defensive leukocytes to tissues
    • Aids hemostasis in case of blood vessel injury
    • Coagulation and Fibrinolytic cascades ensure balance between clotting and bleeding

    Hemostasis

    • Requires: Reflex Vasoconstriction, Initial Platelet plug, Coagulation cascade, and Fibrin stabilisation
    • Platelets:
      • Activated by contact with extravascular material
      • Adhesion to surface, activation, degranulation, and aggregation
    • Secondary haemostasis:
      • Exposure of tissue factor (TF) binds Factor VII, activating Extrinsic Coagulation Cascade
      • Thrombin converts soluble fibrinogen to insoluble fibrin
      • Thrombin recruits further platelets, forming a solid permanent plug

    Counter-Regulatory Mechanisms

    • Fibrinolytic cascade: Tissue plasminogen activator (t-PA) generates plasmin, degrading fibrin
    • Thrombomodulin interferes with the coagulation cascade
    • Mechanisms restrict inappropriate extension of the haemostatic plug beyond the site of injury

    Plasma Proteins

    • Albumin: the major protein (50% of all plasma protein, 4% w/v), transport protein
    • Other proteins: Clotting Cascade, Fibrinolytic Cascade, Kinin cascade, Complement cascade, Antibodies/anti-microbials, Hormones, Inflammatory mediators

    Proteinase Cascades

    • Involved in proteolysis, breakdown of proteins into smaller polypeptides
    • Inactive proteinase substrates are activated by proteinase activity, leading to amplification of an initially small signal

    Normal Haemostasis

      1. Transient arteriolar vasoconstriction: Reflex neurogenic stimulation, Endothelin release
      1. Primary haemostasis: Platelet adhesion and activation, platelet flattening, release of secretary granules, recruitment of additional platelets

    Action Potential

    • Depolarization of the cell membrane occurs when the membrane potential becomes less negative and more positive (+30mV)
    • This is due to the opening of voltage-gated Na+ channels, allowing an influx of Na+ ions
    • The membrane is approximately 600 times more permeable to Na+ ions
    • Local depolarization of the cell membrane causes the spread of depolarization down the axon, but it decays with distance

    Voltage-Gated Na+ Channels

    • These channels are ion-selective, only allowing Na+ ions to pass through
    • They are controlled by a voltage sensor that responds to the level of the membrane potential
    • Normally, these channels are closed, but they open when prompted by a gating agent (voltage above the threshold)

    Action Potential Phases

    • Phase I: Depolarization
    • Phase II: Repolarization (inactivation of voltage-gated Na+ channels, opening of voltage-gated K+ channels, and K+ efflux)
    • Phase III: Hyperpolarization and return to Resting Membrane Potential (RMP)

    Propagation of Action Potential

    • Sequential opening, inactivation, and closing of Na+ and K+ voltage-gated channels cause depolarization and repolarization of the cell membrane
    • After an action potential, there is a refractory period when the membrane is hyperpolarized and not as excitable

    Speed of Action Potential Propagation

    • Axon resistance affects the speed of propagation (larger diameter = less resistance, myelin provides additional insulation)
    • Action potentials are only produced in the exposed spaces of Ranvier's nodes
    • Current spreads under myelin, but unmyelinated nerve has slower conduction due to current leak

    Synaptic Signaling

    • A special case of paracrine signaling that involves a special structure (synapse)
    • Only occurs between cells with a synapse (communication between neurons or between neuron and effector cells)

    Neurotransmission

    • Biological active chemicals (neurotransmitters) that transmit signals from a neuron to another neuron or target cell across a synapse
    • Excitatory neurotransmitters (e.g., Acetylcholine, Noradrenaline, Glutamate) cause influx of Na+ and depolarization
    • Inhibitory neurotransmitters (e.g., GABA, Glycine) cause influx of Cl- and hyperpolarization

    Importance of Action Potential and Neurotransmitters

    • Understanding action potential and neurotransmitters is crucial for health professionals in managing pain and other conditions

    Pain Management

    • tooth pain is transmitted through Aδ fibers (myelinated, fast, sharp pain) and C fibers (unmyelinated, slow, burning sensation)

    Local Anaesthesia

    • Local anaesthetic (e.g., lignocaine) reversibly prevents transmission of the nerve impulse in the region to which it is applied
    • Lignocaine binds to voltage-gated Na+ channels in the peripheral nerve cell membrane and blocks the influx of Na+

    Recap

    • Action potential is a brief reversal of electric polarization of the cell membrane
    • Controlled by movement of ions across the cell membrane
    • Important for communication between cells

    Hyaluronic Acid

    • Formed at the cell surface by an enzyme complex
    • Not sulphated
    • Extremely long chains
    • Acts as a scaffold, binding many proteoglycans
    • Known as the 'goo' molecule
    • A major component of the Extracellular Matrix (ECM), especially abundant in synovial fluid

    Heparan Sulphate

    • Components manufactured in the Golgi
    • Similar to hyaluronic acid, except highly sulphated
    • Regulates a wide range of biological activities, including angiogenesis, blood coagulation, and cellular signalling

    Proteoglycans

    • Consist of a protein core with attached Glycosaminoglycans (GAGs), excluding hyaluronic acid
    • Can form non-covalent complexes with hyaluronic acid
    • Known as the 'filler' of ECM space
    • The major biological function of proteoglycans derives from the physicochemical characteristics of GAGs

    Collagen

    • Synthesized intracellularly and matured extracellularly
    • A major component of the ECM

    Elastin

    • Similar to collagen
    • Hydrophobic uncoiling domains, giving it a 'rubber band' property

    Glycosaminoglycans (GAGs)

    • Also known as mucopolysaccharides
    • Long, unbranched polysaccharides
    • All repeating disaccharide units, consisting of an amino sugar and a uronic acid
    • Strongly negatively charged, often sulphated and carboxyl groups
    • Attract and trap water by strong charge and trapping cations, providing hydration and swelling pressure to withstand compression forces

    ECM turnover

    • Permits remodeling and adaptation to function
    • Synthesis balanced by degradation
    • Degradation by enzymes, such as hyaluronidase, metalloproteinases, and serine proteinases

    Connective Tissue

    • Joins tissues together
    • Usually has blood vessels
    • Cells are separated from each other
    • Extracellular matrix (ECM) consists of collagen, elastin, glycosaminoglycans, and hyaluronic acid
    • Supports the organs and other special tissues
    • Fills in spaces
    • Supports the epithelium (lamina propria)

    Types of Connective Tissue

    • Loose collagenous connective tissue
    • Dense collagenous connective tissue
    • Elastic tissue
    • Bone
    • Cartilage (no blood vessels)
    • Adipose tissue (fat)
    • Blood

    Loose Connective Tissue

    • Has blood vessels, elastin fibers, and fibroblasts
    • Example: small intestinal mesentery

    Dense Connective Tissue

    • Tendon is a good example
    • Has neatly arranged collagen fibers
    • Macroscopically, tendons are white/opaque because they have very few blood vessels
    • Very similar to scar tissue in appearance and structure

    Tendons

    • Join muscles and bones together
    • Sometimes form between tissue masses and organs
    • Lots of collagen fibers, making them hard and rope-like

    Adipose Tissue

    • Special connective tissue
    • Triglyceride/H2O store
    • Structural, especially in hands, soles, orbit, and resist starvation
    • Body contour, influencing sexual morphology

    Bone

    • Highly vascular
    • Calcified collagen
    • Internal structure optimized to resist forces (Wolf's Law)
    • Soft tissue (marrow) in spaces

    Bone Remodeling

    • Always a surface process
    • Key cells involved: osteoblasts, osteocytes, and osteoclasts

    Epithelial Tissues

    • Epithelial cells are tightly bound together and rest on a basement membrane with distinct polarity.
    • They have no vascular supply, and nutrients are delivered by diffusion and mitosis.

    Characteristics of Epithelial Cells

    • They renew continuously by mitosis.
    • They have structural and functional polarity.
    • They are avascular, meaning they have no direct blood supply.

    Roles of Epithelia

    • Protection (skin)
    • Absorption (small and large intestine)
    • Transport of material at the surface (mediated by cilia)
    • Secretion (glands)
    • Excretion (tubules of the kidneys)
    • Gas exchange (lung alveolus)

    Types of Epithelia

    • Squamous (meaning scale-like)
    • Cuboidal
    • Columnar

    Epithelial Tissue Organization

    • Simple epithelial tissue
    • Stratified epithelial tissue
    • Pseudo-stratified epithelial tissue (looks stratified but all cells are in contact with the basement membrane)

    Basement Membrane

    • A specialized extracellular matrix (ECM) sheet
    • Composed of intertwining collagen fibers

    Cell Junctions

    • Desmosomes: keratin-binding, permeable to H2O2 and ions, and able to resist mechanical stress
    • Hemidesmosomes: anchor epithelial cells to the basement membrane
    • Examples of desmosomes and hemidesmosomes can be found in skin, intestines, and respiratory tract

    Clinical Relevance

    • Epithelial transition zone is vulnerable to HPV invasion and subsequent immortalization (cancer) of cervical epithelial cells.

    Central Dogma

    • The central dogma describes the flow of genetic information during cell growth and replication: DNA → RNA → Protein
    • Information doesn't flow backward
    • Proteins and some RNA are considered "gene products"

    Transcription

    • Transcription is the DNA-directed synthesis of RNA
    • Same language is used between DNA and RNA
    • DNA is long, while RNA is short and contains only a few genes
    • In eukaryotes, each gene is transcribed to give a separate mRNA that encodes only a single protein
    • In prokaryotes, an mRNA molecule may carry information from a single gene or from several genes next to each other on the chromosome

    Transcription Process

    • Unwinding of DNA double helix
    • Template strand is used
    • Complementary base pairing occurs
    • RNA polymerase forms RNA
    • Uracil is the base that would be in the RNA sequence that wouldn't be in the DNA sequence being copied

    Types of RNA

    • mRNA: carries gene information
    • tRNA: involved in protein synthesis
    • rRNA: makes up ribosomes
    • MicroRNA: regulates gene expression

    Translation

    • Translation is the synthesis of proteins from RNA
    • mRNA nucleotide sequence is translated into amino acids, which is a different language
    • The genetic code is a dictionary that links a sequence of RNA to an amino acid

    The Genetic Code

    • Problem: 4 different RNA bases, but 20 different amino acids
    • Solution: the genetic code, which links a sequence of RNA to an amino acid
    • Codon: 3 RNA bases that code for 1 amino acid

    Mutations

    • Silent mutations: codon containing a changed RNA base, but codes for the same amino acid
    • Missense mutations: codon contains a changed RNA base, producing a different amino acid

    The Genome

    • The genome is the complete set of information in an organism's DNA
    • Carries information for gene expression, protein synthesis, and more
    • Huge amount of information: 3.0 x 10^9 base pairs of DNA, 20,000-25,000 genes
    • Genes account for 2% of the genome, while 98% is non-coding DNA

    Packaging of the Genome

    • Problem: 2 meters of DNA per cell, but the cell nucleus is only 6μm
    • Solution: DNA is wrapped around histone proteins to form chromatin, which is then wound up to form chromosomes
    • Chromosomes have a centromere (center) and telomere (ends)

    Karyotype

    • A karyotype is the complete set of chromosomes in an organism

    Human Embryo Development

    • At 4 weeks, the human embryo has pharyngeal arches, occipital somites, cervical somites, forelimb bud, heart, and umbilicus.
    • Somites are blocks of mesoderm that form muscle and bone.

    Pharyngeal Arch Formation

    • Pharyngeal arches form at day 23, with the first arch forming on day 22.
    • The pharyngeal arches are formed from the pharyngeal/visceral/branchial region.

    Development of Pharyngeal Arches

    • The first pharyngeal arch appears on day 22, with the second and third arches appearing on day 24, and the fourth and sixth arches appearing on day 29.
    • The contents of the pharyngeal arches include muscle, cartilage, cranial nerves, and blood vessels.

    Development of the Pharynx

    • Pharyngeal pouches form on the endodermal side between the arches, with pharyngeal grooves (or clefts) forming from the lateral ectodermal surface of the neck region to separate the arches.

    Muscle Development

    • Muscle cells from the superior somites invade the pharyngeal arches.
    • The muscles derived from the pharyngeal arches include:
      • First arch: masticatory muscles, mylohyoid, anterior belly of digastric, tensor tympani, and TVP.
      • Second arch: facial expression, posterior belly of digastric, stylohyoid, and stapedius.
      • Third arch: stylopharyngeus.
      • Fourth and sixth arches: intrinsic laryngeal and pharyngeal muscles.

    Cartilage and Bone Development

    • Neural crest cells from the developing brain form cartilage and cranial nerves in the pharyngeal arches.
    • The cartilage and bone derived from the pharyngeal arches include:
      • First arch: Meckel's cartilage (mandible), Palatopterygoquadrate bar (part of sphenoid), malleus, and incus.
      • Second arch: stapes, part of hyoid, and temporal bones.
      • Third arch: part of hyoid.
      • Fourth and sixth arches: larynx cartilage.

    Cranial Nerve Development

    • Neural crest cells from the developing brain form cranial nerves in the pharyngeal arches.
    • The cranial nerves derived from the pharyngeal arches include:
      • First arch: Trigeminal (V2, V3).
      • Second arch: Facial nerve (VII).
      • Third arch: Glossopharyngeal (IX).
      • Fourth and sixth arches: Vagus (X).

    Blood Vessel Development

    • The blood vessels derived from the pharyngeal arches include:
      • First arch: Maxillary artery and external carotid artery.
      • Second arch: Internal carotid artery.
      • Fourth and sixth arches: Arch of the aorta.

    Development of the Face

    • The development of the face involves the formation of the frontonasal process, maxillary process, and mandibular process.
    • The face develops from the fusion of the frontonasal process, maxillary process, and mandibular process.

    Development of the Hard Palate

    • The development of the hard palate involves the formation of the primary palate and the secondary palate.
    • The primary palate is formed from the fusion of the medial nasal processes, while the secondary palate is formed from the fusion of the maxillary process and the palatal shelves.
    • The hard palate is formed from the ossification of the maxilla and the mid-palatal suture.

    Malformations of the Face and Palate

    • Cleft lip and palate can occur due to the failure of fusion of the maxillary process and the medial nasal process.
    • Cleft palate can occur due to the failure of fusion of the palatal shelves.
    • Orofacial clefts occur in 1 in 700 births, with cleft lip with cleft palate occurring in 1 in 1600 births, and cleft palate without cleft lip occurring in 1 in 2800 births.
    • Cleft palate is more common in females than males, with a ratio of 2:1.
    • Cleft palate often occurs with other defects in one-third of cases.

    Stages of Tooth Development

    • There are six stages of tooth development: initiation, bud, cap, bell, root formation, and eruption
    • Each stage is characterized by specific changes in the structure and formation of the tooth

    Initiation Stage

    • The initiation stage is the first stage of tooth development
    • It is characterized by the formation of the primary epithelial band and the dental lamina

    Bud Stage

    • The bud stage is the second stage of tooth development
    • It is characterized by the formation of the bud and the condensation of ectomesenchyme

    Cap Stage

    • The cap stage is the third stage of tooth development
    • It is characterized by the formation of the cap and the differentiation of the inner enamel epithelium

    Bell Stage

    • The bell stage is the fourth stage of tooth development
    • It is divided into early and late bell stages
    • The early bell stage is characterized by the formation of the papilla and the differentiation of the inner enamel epithelium
    • The late bell stage is characterized by the formation of the cervical loop and the differentiation of the outer enamel epithelium

    Root Formation Stage

    • The root formation stage is the fifth stage of tooth development
    • It is characterized by the formation of the root sheath and the differentiation of odontoblasts

    Tooth Structure

    • A tooth is composed of enamel, dentine, and cementum
    • The enamel is the outermost layer of the tooth
    • The dentine is the layer beneath the enamel
    • The cementum is the layer that covers the root of the tooth

    Enamel Formation

    • Enamel is formed by the differentiation of ameloblasts
    • The ameloblasts produce enamel matrix proteins that are deposited on the dentine
    • The enamel matrix proteins are then mineralized to form the enamel

    Dentine Formation

    • Dentine is formed by the differentiation of odontoblasts
    • The odontoblasts produce dentine matrix proteins that are deposited on the pulp
    • The dentine matrix proteins are then mineralized to form the dentine

    Cementum Formation

    • Cementum is formed by the differentiation of cementoblasts
    • The cementoblasts produce cementum matrix proteins that are deposited on the root of the tooth
    • The cementum matrix proteins are then mineralized to form the cementum

    What are Micro-organisms?

    • Micro-organisms are defined as organisms too small to be seen by the unaided eye, less than 1mm in diameter.
    • They are important because they make life possible, produce foods, and cause disease.

    Classes of Microbes

    • Cellular microorganisms:
      • Bacteria (e.g. Escherichia coli, Porphymonas gingivalis)
      • Archea (e.g. Methanogens)
      • Fungi (e.g. Yeasts)
      • Protists (e.g. Algae, Protozoa, Slime molds)
    • Acellular microorganisms:
      • Viruses (e.g. HIV, Herpes, COVID)
      • Viroids (RNA, plant diseases)
      • Virusoids (nucleic acids, animal diseases)
      • Prions (infectious proteins, e.g. scrapie and mad cow disease)

    Characteristics of Micro-organisms

    • Bacteria:
      • Prokaryotes
      • Single-celled
      • Cell walls contain peptidoglycan
      • Ubiquitous in environment and human microbiome
      • Diseases: caries, periodontal disease, skin infections, food poisoning
    • Fungi:
      • Eukaryotes
      • Diverse group
      • Unicellular (e.g. yeasts) or multicellular (e.g. molds and mushrooms)
      • Role in oral thrush (e.g. Candida albicans)
    • Protists:
      • Algae: produce 50% of the world's oxygen
      • Protozoa: motile, hunter-gatherers
      • Slime molds
      • Water molds
      • Human disease: e.g. malaria

    Importance of Micro-organisms

    • Microbes are involved in human disease
    • Koch's postulates: a set of criteria to establish a causal link between a microbe and a disease
    • Reservoirs of microbes: humans, animals, soil, water
    • Mechanisms of transmission: direct contact, vectors, airborne, waterborne

    Summary

    • Microbes are diverse and divided into cellular and acellular groups
    • Microbes are involved in many human diseases, particularly oral infections
    • Understanding micro-organisms is important for human health and disease prevention

    Bacterial Morphology and Nomenclature

    • Bacteria can be classified based on their morphology (shape and arrangement) and nomenclature (naming convention)

    Morphology

    • Bacterial shapes:
      • Cocci: round or spherical
      • Bacilli: rod-shaped
      • Spirochaetes: spiral-shaped
      • Other shapes: filamentous, curved, pleomorphic
    • Bacterial arrangements:
      • Clumps: e.g., Staphylococci
      • Chains: e.g., Streptococci
      • Twos/Diplo: e.g., Diplococci
      • Fours/Tetrads: e.g., Micrococci
      • Eights/Cubic: e.g., Sarcina sp. mutans

    Respiration

    • Aerobes: require oxygen (O2)
    • Anaerobes: require carbon dioxide (CO2)

    Classification of Bacteria

    • Historical criteria:
      • Staining (Gram-positive or Gram-negative)
      • Shape (rods, cocci)
      • Respiration (aerobes or anaerobes)
    • Modern criteria:
      • Genomic similarity (DNA sequence similarity to reference sequences)

    Nomenclature

    • Latin name: e.g., Escherichia coli K1
    • Genus species strain: e.g., Escherichia coli K1
    • Strain: descendants of a single cell with a distinct characteristic(s)
    • Species: a collection of strains that share many stable properties and differ significantly from other groups of strains
    • Genus: a group of species exhibiting similar characteristics
    • Species name: written in italics, with genus name capitalized and species name in lowercase

    Phylogenetic Tree

    • Based on genetic data
    • Tips represent nucleotide sequences
    • Origin: last common ancestor
    • Branching points: represent a divergence event
    • Distance between tips: reflects the number of genetic changes

    Bacterial Growth Curve

    • The growth curve consists of four phases: Lag, Exponential, Stationary, and Death.
    • Lag phase: adjustment period, bacteria adapting to new environment, replicating chromosomes to build new proteins/enzymes.
    • Exponential phase: cells growing and dividing, maximal growth, continues until nutrients are exhausted or inhibitory molecules accumulate.
    • Stationary phase: cell numbers stop increasing, DNA replication is arrested, cells produce new proteins to enhance survival during starvation.
    • Death phase: cells stop growing, even if supplied with new medium.

    Bacterial Growth in Oral Environment

    • Lag phase: immediately after a meal, adjusting to new influx of nutrients.
    • Exponential phase: after meal, post adjustment, cells dividing maximally.
    • Stationary phase: period of fasting in between meals, nutrients limited, bacteria susceptible to antimicrobials.
    • Death phase: variable between bacteria.

    Growing Bacteria in the Lab

    • Media consistency: solid, semi-solid, and liquid media support bacterial growth.
    • Solid media: allows for isolation of single colonies.
    • Semi-solid media: for microaerophilic bacteria.
    • Liquid media: allows for uniformed growth until either nutrient limitation or build-up of inhibitors.

    Bacteria Quantification

    • Methods: cell counting under a microscope, serial dilution and plating on agar, qPCR.
    • qPCR: relative quantification or absolute quantification.

    Optical Density

    • Measuring optical density at wavelength 600 nm is typically used to interrogate growth dynamics in the lab.

    Conditions Affecting Bacterial Growth

    • Temperature: most bacteria grow optimally at 37°C, but can vary between 0°C and 121°C.
    • pH: most bacteria grow optimally between pH 7-8, but can vary between pH 0 and 11.
    • Oxygen: strict aerobes require oxygen, facultative aerobes prefer oxygen, facultative anaerobes prefer no oxygen, and strict anaerobes cannot grow in oxygen.

    Culture Media

    • Defined media: exact composition known.
    • Complex media: extracts from plants or animal, exact composition unknown.
    • Additives can be incorporated to enrich or inhibit certain bacteria.

    Gut Microbiota

    • The stomach has a highly acidic environment, resulting in few viable bacteria.
    • The small intestine is acidic with bile juices, which also limits the presence of viable bacteria.
    • The large intestine has a huge diversity of bacteria, with 10^12 cells per gram of stool.
    • Symbiotic relationships between gut microbiota and the host:
      • Produce biotin and vitamin K.
      • Prevent pathogens from colonizing.
      • Aid in the absorption of nutrients.

    Oral Microbiota

    • The mouth is colonized soon after birth.
    • After tooth eruption, anaerobes such as Porphymonas, Prevotella, and Fusobacterium species increase.
    • Symbiotic relationships between oral microbiota and the host:
      • Alter taste perception.
      • Distinguish between super-tasters and non-tasters.
      • Vary in tongue microbiota.

    Changes to the Oral Microbiota

    • The oral microbiome can modulate nitric oxide homeostasis and blood pressure in humans.

    Homeostasis and Dysbiosis

    • Dysbiosis is an example of changes to the microbiota, such as in obesity.
      • Germ-free mice versus conventional mice on the same diet.
      • Germ-free mice can eat more and gain less weight than conventional mice.
      • Microbiota affects caloric absorption.
    • Dysbiosis can cause dental conditions, including:
      • Dental caries.
      • Periodontal disease.
      • Oral cancer.

    Microbe-Host Interaction

    • Humans are holobionts, consisting of a host and microbiome.
    • Microbes can be beneficial or cause harm.
    • The microbiome across the human body is diverse and can be in flux.

    Host-Microbe Interactions

    • Infection/colonization: the acquisition of microorganisms by the host.
    • Commensalism: a state of infection that results in no damage to the host.
    • Symbiosis/mutualism: a state of infection where both the host and microbe benefit.

    Humans as Holobionts

    • A holobiont is a host and its microbiome.
    • The human microbiome consists of all microbes that share our body space.
    • Humans carry 10^14 microbial cells and 10^13 human cells.
    • Humans need their microbiome for beneficial tasks and protection from foreign substances and pathogens.

    Microbiome - Commensals

    • Commensals are 'normal' microbes present on the skin and in the oral, respiratory, and gastrointestinal tracts.
    • They protect the host against pathogens and provide nutrients.
    • Commensals are acquired in the first year of life.

    Microbiome Composition

    • The microbiome has a huge diversity in composition, including bacteria, fungi, and viruses.
    • Some members are culturable, while most cannot be cultured.
    • Culture-independent methods are used to study the microbiome.

    16S Ribosomal RNA Sequencing

    • 16S rRNA is a subunit of the ribosome.
    • It has a slow rate of evolution and is highly conserved between bacteria and archaea.
    • It has hypervariable regions that can be used to study diversity.

    Shotgun Metagenomics

    • Shotgun metagenomics involves sequencing every nucleic acid within a given sample, including DNA and RNA.
    • It can be used to study bacteria, viruses, fungi, and even host DNA.
    • It allows for extended characterization of the community, including subtyping, AMR genes, and virulence genes.

    Metagenomics Can Be Used for Insights into Population Dynamics

    • Metagenomics can provide insights into population dynamics.

    Host Microbiome Varies with Body Site

    • The microbiome varies across different body sites, including the skin, gut, and oral cavity.

    Skin Microbiota

    • The skin environment is slightly acidic, with high salt, low water content, and inhibitory substances.
    • Bacteria are present on superficial skin (dead cells) and sweat glands.
    • Bacteria partially degrade skin oil to volatile fatty acids, contributing to body odor.

    Respiratory Microbiota

    • The respiratory microbiota has a specific composition and function.

    Gut Microbiota

    • The stomach has a highly acidic environment, resulting in few viable bacteria.
    • The small intestine is acidic with bile juices, which also limits the presence of viable bacteria.
    • The large intestine has a huge diversity of bacteria, with 10^12 cells per gram of stool.
    • Symbiotic relationships between gut microbiota and the host:
      • Produce biotin and vitamin K.
      • Prevent pathogens from colonizing.
      • Aid in the absorption of nutrients.

    Oral Microbiota

    • The mouth is colonized soon after birth.
    • After tooth eruption, anaerobes such as Porphymonas, Prevotella, and Fusobacterium species increase.
    • Symbiotic relationships between oral microbiota and the host:
      • Alter taste perception.
      • Distinguish between super-tasters and non-tasters.
      • Vary in tongue microbiota.

    Changes to the Oral Microbiota

    • The oral microbiome can modulate nitric oxide homeostasis and blood pressure in humans.

    Homeostasis and Dysbiosis

    • Dysbiosis is an example of changes to the microbiota, such as in obesity.
      • Germ-free mice versus conventional mice on the same diet.
      • Germ-free mice can eat more and gain less weight than conventional mice.
      • Microbiota affects caloric absorption.
    • Dysbiosis can cause dental conditions, including:
      • Dental caries.
      • Periodontal disease.
      • Oral cancer.

    Microbe-Host Interaction

    • Humans are holobionts, consisting of a host and microbiome.
    • Microbes can be beneficial or cause harm.
    • The microbiome across the human body is diverse and can be in flux.

    Host-Microbe Interactions

    • Infection/colonization: the acquisition of microorganisms by the host.
    • Commensalism: a state of infection that results in no damage to the host.
    • Symbiosis/mutualism: a state of infection where both the host and microbe benefit.

    Humans as Holobionts

    • A holobiont is a host and its microbiome.
    • The human microbiome consists of all microbes that share our body space.
    • Humans carry 10^14 microbial cells and 10^13 human cells.
    • Humans need their microbiome for beneficial tasks and protection from foreign substances and pathogens.

    Microbiome - Commensals

    • Commensals are 'normal' microbes present on the skin and in the oral, respiratory, and gastrointestinal tracts.
    • They protect the host against pathogens and provide nutrients.
    • Commensals are acquired in the first year of life.

    Microbiome Composition

    • The microbiome has a huge diversity in composition, including bacteria, fungi, and viruses.
    • Some members are culturable, while most cannot be cultured.
    • Culture-independent methods are used to study the microbiome.

    16S Ribosomal RNA Sequencing

    • 16S rRNA is a subunit of the ribosome.
    • It has a slow rate of evolution and is highly conserved between bacteria and archaea.
    • It has hypervariable regions that can be used to study diversity.

    Shotgun Metagenomics

    • Shotgun metagenomics involves sequencing every nucleic acid within a given sample, including DNA and RNA.
    • It can be used to study bacteria, viruses, fungi, and even host DNA.
    • It allows for extended characterization of the community, including subtyping, AMR genes, and virulence genes.

    Metagenomics Can Be Used for Insights into Population Dynamics

    • Metagenomics can provide insights into population dynamics.

    Host Microbiome Varies with Body Site

    • The microbiome varies across different body sites, including the skin, gut, and oral cavity.

    Skin Microbiota

    • The skin environment is slightly acidic, with high salt, low water content, and inhibitory substances.
    • Bacteria are present on superficial skin (dead cells) and sweat glands.
    • Bacteria partially degrade skin oil to volatile fatty acids, contributing to body odor.

    Respiratory Microbiota

    • The respiratory microbiota has a specific composition and function.

    Disadvantages of Living in a Biofilm

    • Slow diffusion of nutrients and buildup of by-products due to biofilm structure
    • Difficulty in removing substances, leading to buildup of heavy metals
    • Bacteriocins, protein toxins that target similar bacteria, produced by S. salivarius to reduce URT infections

    Oral Microbiology

    • 6 months of childhood: tooth emergence and establishment of solid foods, leading to increased diversity of oral microbiome
    • Bacterial taxa emerging during this period include Fusobacterium, Lactobacillus, Neisseria, Gemella, and Haemophilus
    • Streptococcus species dominate the infant oral microbiome in early childhood, with a narrow diversity
    • Impact of delivery mode and early feeding on oral microbiome development
    • Type of milk consumed influences early diversity, with breast-fed infants having higher abundances of Streptococcus and Veillonella species

    Plaque Development

    • Mutans exchange DNA to enable bacteria to tolerate acidic conditions
    • Advantages and disadvantages of life within a biofilm

    Learning Objectives

    • Know stages of microbial colonization of the oral cavity
    • Understand factors influencing microbial colonization of the oral cavity
    • Know factors causing changes in oral microbial composition over time
    • Know stages of plaque development
    • Know advantages and disadvantages of life within a biofilm

    Leukocytes (White Blood Cells)

    • Neutrophilic PMN (most common WBC):
      • Kills bacteria
      • Makes pus
      • Involved in immunity against parasitic infections, especially in the intestine
      • Plays a role in allergies and asthma
    • Monocytic PMN:
      • Kills bacteria
      • Eats debris
      • Attacks intracellular pathogens
      • Has a wide role in immunity
      • Can become macrophages
    • Lymphocytes (second most common type of WBC):
      • Includes T, B, and NK cells
      • Involved in specific immunity
      • Provides immunity against viruses
      • Involved in tumor protection
    • Eosinophils (rarest variety of WBC in blood):
      • Can become mast cells
      • Contributes to allergy

    Chemotaxis

    • Directional movement of neutrophils towards bacteria
    • Triggered by low molecular weight products released by bacteria, such as fMLP and peptidoglycan
    • Neutrophils have surface receptors that detect these products

    Opsonisation

    • Coating of microorganisms by complement system to facilitate phagocytosis
    • Recognized by special receptors on phagocytic cells

    Phagocytosis

    • Capture and digestion of foreign particles by phagocytic cells
    • Chemokines attract macrophages and neutrophils to infected tissues
    • Opsonins attach to microbes to increase phagocyte adhesion

    Killing Mechanisms

    • Oxygen-independent pathway: uses lysosomal enzymes (collagenase, gelatinase, phospholipases, or serine proteases)
    • Oxygen-dependent pathway: uses reactive oxygen and nitrogen species (RONS)

    Innate Immune System

    • Cells:
      • Antigen-presenting cells (APCs): dendritic cells, macrophages, B cells
      • Phagocytic cells: neutrophils, macrophages
    • Pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs)
    • Effects of activating TLRs:
      • Cytokine production (IL-1, TNF) leading to fever and inflammation
      • Chemokine production leading to cell recruitment
      • Activation of bacterial killing mechanisms
      • Activation of dendritic cells

    Acquired Immunity

    • Has a memory, providing improved protection against future infections
    • Basis for immunity against re-infection and immunization

    Cells of the Immune System

    • Dendritic cells originate from bone marrow, with myeloid/monoblast origins
    • Can be tissue-derived (conventional DC) or blood-derived
    • Functions: antigen trap, antigen processing, migration, cytokine production (e.g., IL-12)
    • Expresses Class II MHC and presents antigens to T-cells

    Antigen-Presenting Cells (APCs)

    • Sedentary in epithelium/dermis, migrate to draining lymph node, and change phenotype
    • Functions: antigen processing, antigen presentation (non-phagocytic)
    • Examples: dendritic cells, macrophages, B cells, Langerhans cells

    Antigen Presentation to T-Cells - MHC

    • MHC class I: expressed on all nucleated cells, present self-antigens
    • MHC class II: expressed on professional APCs (dendritic cells, macrophages, B cells, Langerhans cells), present foreign antigens
    • Each MHC displays one peptide-MHC complex at a time, with high expression levels increasing the propensity to activate T-cells

    MHC Checkpoints for Activation

    • MHC-TCR engagement requires co-stimulation (CD28-CD80/CD86)
    • IL-2 is released by T cells, promoting proliferation
    • 'Brake pads' (CTLA-4) limit expansion after activation
    • 3 signals for T-cell activation: TCR-MHC engagement, CD4/8-MHC binding, CD28-CD80/86 binding

    Adaptive (Specific) Immunity - Characteristics

    • Specificity: recognizing pathogen epitopes
    • Memory: accelerated and larger response upon re-exposure
    • Self-limitation: mass apoptosis of lymphocytes in the absence of antigen presentation

    Antigen Recognition - B Cells and Activation

    • T-dependent antigens (e.g., soluble proteins) require T-cell 'help' (CD40, cytokines)
    • T-independent antigens (e.g., lipids, polysaccharides) do not require T-cell help
    • B1 cells produce 'natural antibody' (IgM only)
    • Each B-cell has a unique specificity, with 10 billion possible combinations

    Course Overview

    • The course covers head and neck anatomy for oral health therapists
    • Aim is to provide students with an understanding of the anatomy of the head and neck

    Learning Outcomes

    • Perform extra- and intra-oral examinations
    • Understand and assess oral health condition, and diagnose oral health diseases
    • Give local anaesthesia
    • Extract teeth
    • Recognise variations of normal anatomy and pathology

    Anatomical Knowledge

    • Identify the major landmarks of the orofacial region
    • Identify the bones of the skull
    • Identify the ‘muscles of facial expression’, muscles of the neck, ‘muscles of mastication’ and muscles of the tongue
    • Describe the blood circulation, lymph nodes and glands of the head and neck
    • Describe the basic nervous system biology
    • Describe the innervation of the face, head and neck, including the teeth
    • Identify the anatomical landmarks of the oral cavity relevant to local anaesthesia
    • Identify and describe the components of the temporomandibular joint (jaw joint), (TMJ)

    Course Outline - Semester 1

    • Introduction to course and anatomical terminology
    • Oral Cavity
    • Skull (osteology): cranial bones and vertebrae
    • Skull (osteology): facial bones
    • Muscles: facial expression
    • Muscles: mastication, tongue and neck

    Course Outline - Semester 2

    • Circulation
    • Nervous system and cranial nerves
    • Trigeminal nerve
    • Salivary glands
    • Lymph nodes
    • Temporomandibular joint

    Resources

    • Lectures
    • Tutorials
    • Online material: Glossary, Online Wilson Museum, Acland anatomy videos, Thieme Atlas, Electronic textbooks
    • Introductory Textbooks: Fehrenbach and Herring, 2007, Illustrated anatomy of the head and neck; Phinney and Halstead, 2011, Dental assisting coloring book
    • Advanced Textbooks: Anatomy: A Photographic Atlas (9th Edition)

    Lecture 1: Introduction to Head & Neck Anatomy

    • Introduction to the anatomy course
    • Anatomical Terminology: Planes, Laterality, Movement

    Movement Terminology

    • Lateral Flexion: movement of head towards shoulder
    • Rotation: turning the head around to a particular side away from midline
    • Elevation & Depression: moving a body part superiorly or inferiorly
    • Protraction & Retraction: jutting jaw out and bringing it back
    • Abduction: moving away from midline
    • Adduction: moving towards midline

    Soft Palate

    • Contains muscles, aponeuroses, fat, and glands
    • Muscles and aponeuroses are part of the palatine muscles
    • Fat and glands are present in the soft palate

    Palatine Aponeurosis

    • Thin, firm, fibrous sheet formed by the expanded tendon of the tensor palati muscle
    • Provides support to the other palatine muscles that attach to it and gives strength to the soft palate

    Muscles of Palate

    • There are five paired palatal muscles:
      • Levator palati: lifts the palate up and back
      • Tensor palati: tightens the palate and pulls the auditory tube open
      • Palatoglossus: forms the posterior pillar of the fauces
      • Palatopharyngeus: forms the posterior pillar of the fauces
      • Exhibits first signs of inflammation through redness, bleeding, or swelling

    Gingiva (Gums)

    • Gingiva proper: covers the alveolar processes of the maxilla and mandible and finishes at the neck of each tooth
    • Two types of gingiva:
      • Free gingiva: forms a collar around the tooth and is not attached to bone (normally 1-3mm depth)
      • Attached gingiva: adjacent to free gingiva and is firmly attached to bone structure (can range 3-12mm in height)

    Tongue

    • Mobile muscular organ
    • Two parts: oral (moveable part) and pharyngeal (non-moveable part)
    • Covered in mucous membrane
    • Functions:
      • Speaking
      • Mastication
      • Taste
      • Swallowing

    Tongue Structure

    • Dorsal (upper) surface:
      • Oral (anterior 2/3) and pharyngeal (posterior 1/3) parts are divided by the palatoglossal arch and sulcus terminalis
      • Foramen caecum: remnant of the embryological duct associated with the thyroid gland
    • Ventral (inferior) surface:
      • Body: oral part of the tongue
      • Apex: tip of the tongue
      • Root: connected to the hyoid bone via the hyoglossus and genioglossus muscles

    Oral Tongue – Dorsal

    • Lingual papilla:
      • Fungiform (white circle)
      • Filiform (fur)
      • Vallate (7-12, mushroom)
    • Taste buds associated with all except filiform papillae

    Oral Tongue – Ventral

    • Frenulum
    • Deep lingual veins
    • Fimbriated folds (slight fold of mucous membrane)
    • Sublingual folds with openings and sublingual papilla (prominence of mucous membrane that overlies the sublingual gland, has openings for sublingual and submandibular glands)

    Extrinsic Muscles of Tongue (Position the tongue)

    • Genioglossus: upper genial tubercle to hyoid bone and base of tongue, protrusion/deviation
    • Hyoglossus: hyoid bone to side of tongue, depresses side of tongue (sucking, retraction)
    • Styloglossus: styloid process to side of tongue, lifts tongue up and back
    • Palatoglossus: palatal aponeurosis to side of tongue, tongue up

    Intrinsic Muscles of Tongue (Shape the tongue)

    • Superior longitudinal muscles: elevate, assist in retraction
    • Transverse and vertical muscles: narrow the tongue, and pull the tongue towards the floor of the mouth
    • Inferior longitudinal muscles: deviate the tongue to the side and pull the tip of the tongue downwards, also assists in retraction

    Intervertebral Disc and Vertebral Spine

    • Intervertebral discs provide cushioning to reduce stress of impact, protect nerves, and allow movement.
    • Synovial joints allow for motion of the vertebral spine.

    Cranial Fossae

    • The internal cranial cavity has three cranial fossae: anterior, middle, and posterior.
    • Each fossa has a specific floor and boundaries.

    Anterior Cranial Fossa

    • Floor: orbital plate of frontal bone and lesser wing of sphenoid bone.
    • Features: cribriform plate, crista galli, and olfactory nerve filaments.

    Ethmoid Bone

    • Features: crista galli, cribriform plate, perpendicular plate, superior and middle nasal conchae, medial wall of orbit, and ethmoidal air cells.

    Middle Cranial Fossa

    • Floor: body of sphenoid bone medially and greater wing of sphenoid bone laterally.
    • Features: hypophyseal fossa, pituitary gland, and posterolateral boundaries.

    Sphenoid Bone

    • Features: greater and lesser wings, body, hypophyseal fossa, sphenoid sinus, orbital surface, optic canal, superior orbital fissure, and pterygoid plates.

    Posterior Cranial Fossa

    • Floor: occipital bone and petrous temporal bone.
    • Features: clivus and posterior boundaries.

    Skull Bones

    • The skull consists of 22 bones: 8 cranial bones and 14 facial bones.
    • Cranial bones: frontal, temporal, parietal, occipital, ethmoid, and sphenoid.
    • Facial bones: maxilla, zygomatic, lacrimal, nasal, inferior nasal conchae, palatine, mandible, and vomer.

    Skull Features

    • The articulations between the bones are mostly non-moveable sutures, fibrous joints that may ossify with age.
    • Exceptions to this are the Temporomandibular Joint (TMJ) and the ossicles of the ear.
    • Terminology: body, processes/plates/spines, and eminence.

    Facial Bones

    • The facial skeleton consists of 14 bones that form the orbit, nasal cavity, oral cavity, and paranasal sinuses.
    • The facial bones are frontal, nasal, maxilla, mandible, zygomatic, sphenoid, temporal, parietal, lacrimal, inferior nasal concha, and ethmoid.

    Orbit

    • The orbit is formed by 7 bones: frontal, ethmoid, sphenoid, zygomatic, lacrimal, maxilla, and palatine.
    • The zygomatic bone forms the infraorbital margin and articulates with maxilla, frontal, temporal, and sphenoid bones.
    • The lacrimal bone contributes to the medial wall of the orbit and contains the nasolacrimal duct.

    Maxilla

    • The maxilla is a paired bone that contributes to the orbit, nasal cavity, and oral cavity.
    • The maxilla articulates with nasal, lacrimal, zygomatic, ethmoid, vomer, and palatine bones.
    • The maxilla has a frontal process, infraorbital groove, maxillary tuberosity, anterior nasal spine, infra-orbital foramen, zygomatic process, and alveolar process with teeth.

    Nose and Nasal Cavity

    • The external structure of the nose is formed by the nasal bone, frontal process of maxilla, and nasal process of frontal bone.
    • The nasal cavity has a floor, roof, and lateral wall formed by 8 bones: nasal, frontal, ethmoid, sphenoid, maxilla, lacrimal, inferior nasal concha, and palatine.
    • The nasal septum has a cartilaginous part anteriorly and a bony part posteriorly.

    Other Bones

    • The mandible is a bone that forms the lower jaw.
    • The hyoid bone is not part of the facial skeleton.
    • The paranasal sinuses are air-filled cavities within the facial bones.
    • The oral cavity is formed by the maxilla, mandible, and palatine bones.

    Muscles of Facial Expression

    • Muscles of facial expression are skeletal muscles, meaning they are voluntary, striated, and attached to bones, cartilages, ligaments, fascia, organs, skin, or mucous membranes.

    Categories of Muscles in the Head and Neck Region

    • Muscles in the head and neck region can be categorized into:
      • Muscles of facial expression
      • Muscles of mastication (chewing and swallowing)
      • Muscles of the tongue (swallowing)
      • Muscles of the neck (movement of head and neck, speaking)

    Muscles of Facial Expression

    • All muscles of facial expression are paired except for the orbicularis oris
    • Muscles of facial expression generally originate from bone and insert into skin, where short tendons intertwine with collagen of the dermis

    Scalp, Forehead, and Eyebrows

    • Occipitofrontalis muscle:
      • Has two bellies: frontal and occipital, joined by epicranial aponeurosis
      • Origins: frontal belly from aponeurosis to skin of eyebrows, occipital belly from superior nuchal line to aponeurosis
      • Actions: surprise, frown
    • Corrugator supercilli muscle:
      • Origin: supraorbital ridges
      • Insertion: skin of eyebrow
      • Action: frown
    • Procerus muscle:
      • Origin: nasal bones
      • Insertion: skin of eyebrow
      • Action: frown

    Muscles of the Neck

    • Anterior/Lateral muscles of the neck include:
    • Suprahyoid muscles: Digastric, Mylohyoid, Stylohyoid, Geniohyoid
    • Infrahyoid muscles: Omohyoid, Thyrohyoid, Sternohyoid, Sternothyroid

    Posterior Triangle

    • Muscles in the floor of the posterior triangle include:
    • Splenius capitus muscle
    • Levator scapulae muscle
    • Scalene muscles (posterior, middle, anterior)

    Triangles of the Neck

    • The triangles of the neck are regions of the anterior and lateral neck used to describe the location of key features
    • The boundary between the anterior and posterior triangle of the neck is divided by the Omohyoid muscle

    Muscles and Attachments

    • Sternocleidomastoid muscle:
    • Attachments: from sternum and clavicle to mastoid process (temporal bone)
    • Function: tilts and rotates the head (single), flexes head and raises sternum (paired)
    • Trapezius muscle:
    • Attachments: external occipital protuberance and superior nuchal line to ligamentum nuchae, spinous processes of T12, clavicle, and scapula
    • Function: moves shoulder and scapula, extends the head

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