Compendium 2 Notes PDF

Lecture notes {1} The cell - The structural and functional unit of all living things including humans - Plasma, membrane, cytoplasm containing organelles, nucleus Functional characteristics of cells - Cell metabolism and energy use - All of the chemical reactions carried out wi...

Lecture notes {1} The cell - The structural and functional unit of all living things including humans - Plasma, membrane, cytoplasm containing organelles, nucleus Functional characteristics of cells - Cell metabolism and energy use - All of the chemical reactions carried out within the cell - Synthesis of molecules - Cells making molecules - Communication - Sending or receiving chemical or electrical messages - Reproduction and inheritance - Dividing and reproducing (mitosis or meiosis) Human Cell - Made up of - Plasma membranes - Cytoplasm - Cytoskeletons - Nucleus - Ribosomes - Golgi apparatus - Lysosomes - Mitochondria - Centrioles - Cilia - Microvilli - There are different amounts of the different organelles depending on the cell's function Plasma Membrane - Also known as the cell membrane, sarcolemma or plasmalemma - Function: - Encloses and supports cellular contents - Controls what goes into the cell and what comes out - Regulates intracellular vs extracellular material - Role in intercellular (cell-to-cell) communication - Production of a charge difference (membrane potential) across the membrane - Structure - Lipid bilayer (phospholipid bilayer and cholesterol)(45-50%) - Provides flexibility to the cell - Polar heads facing water in the interior and exterior of the cell are hydrophilic - Non-polar tails facing each other on the interior of the membrane are hydrophobic - Carbohydrates (4-8%) - Protein (45-50%) - Fluid mosaic model - Glycocalyx (the outer surface of the membrane) - Glycoproteins (proteins and carbohydrates) - Glycolipids (lipids and carbohydrates) - Carbohydrates Cytoplasm - Cellular fluid material outside the nucleus but within the boundaries of the plasma membrane - The organelles all sit within the cytoplasm - Cytosol is a component of the cytoplasm and it is a viscous solution containing water with a lot of ions and proteins dissolved in it - Fluid portion of the cytoplasm (ions and protein and water) - Cytoplasmic inclusion -- aggregates of chemicals (made in the cell or transported into the cell e.g. melenin) - Cytoskeleton -- supports the cell and movement of its organelles and changes of the shape of the cell - Supports the cell and its organelles - Responsible for changes to the shape of the cell and its organelles - Microtubules -- hollow, made of tubulin. Internal scaffold, transport, cell division - Microfilaments -- actin, structure, support or microvilli, contractility, movement - Intermediate filaments -- mechanical strength A diagram of a cell cycle Description automatically generated Nucleus and cytoplasmic organelles - Small specialised structures with particular functions - Most have membranes that separate the interior of the organelles from the cytoplasm - The abundance of each organelle is related to the specific structure and function of the cell Nucleus - Function: - Control centre of the cell - Deoxyribonucleic Acid (DNA) in the nucleus carries the code for the structural and functional characteristics of the cell - Structure - Nuclear envelope -- a bilayer membrane surrounding the nucleus. Porous - Nucleoplasm - Nucleolus -- primarily produces ribosomes - Chromosome structure - Chromatin: DNA complexed with proteins (histones) - During cell division chromatin divides into pairs of chromatids called chromosomes. Each pair of chromatids is joined by a centromere Ribosomes - Function: - Sites of protein synthesis - The site where amino acids are assembled into proteins - Nucleus, nucleolus and cytoplasm - Structure: - Compromised of two subunits: large and small - Free ribosomes (floating within the cytoplasm) and membrane-bound ribosomes (attached to endoplasmic reticulum) Endoplasmic reticulum - Structure: - Located near the nucleus - Fattened , interconnecting sacs and tubules - Rough endoplasmic reticulum -- with ribosomes - Smooth endoplasmic reticulum -- without ribosomes - Function: - Rough endoplasmic reticulum: - Synthesis and modification of proteins - Smooth endoplasmic reticulum: - Site of lipid, steroid and carbohydrate synthesis - Detoxification of harmful substances such as drugs - Breakdown of glycogen to glucose Golgi Apperatus - Spelt with a capital 'G' for Camillo Golgi - Structure: - Flattened membranous sacs with cisternae - Secretory vesicles -- where proteins leave the Golgi - Function - Modifies, packages and distributes proteins and lipids that are made in the rough endoplasmic reticulum -- for secretion or internal use by the cell Lysosomes - Structure - Membrane-bound vesicles that form at the Golgi apparatus - Contain enzymes within them - Function - The cells demolition crew - Digestion of molecules (nucleic acid, proteins, lipids, carbohydrates, ect.) that are no longer needed by the cell - Fuses with a vesicle containing something the cell doesn't need anymore and the lysosomes digestive enzymes break down and get rid of the unwanted cell contents Mitochondria - Structure - 2 membranes - Outer membrane and an inner membrane - Between the two is the intermembrane space - Matrix - Space inside the folds tat continuously changes shape - Important because his is where many of the main reactions tske place for ATP synthesis - Has its own DNA with the ability to reproduce itself - Function - 'power plant' of the cell - Increase in number when cell energy requirements increase - High in cardiac and neurons, increase in skeletal muscle in response to exercise - ATP (adenosine triphosphate) production and supply - ATP is the unit of currency for energy Centrioles - Structure - Barrel shaped orgsnelles orientated at right angles to each other - The wall of centrioles is composed of microtubules - Two centrioles can be found in the centrosome (centre of the cell) - Function - Cell division - Meiotic spindles grow from the centrioles - They move to opposite ends of the cell Cilia - Structure - Whip like, motile cellular extensionswhich project from the outer surface of certain cells - Looks like seaweed or grass - Function - Movement of substances across the surface of cells - E.g. cilia lining the respitory tract hich move mucus out of the lungs - E.g. cilia in the fallopian tubes which moves the egg from the ovary to the uterus Flagella - Structure - Similar to cilia but longer - Found on human sperm cells (only one flagellum per sperm) - Function - Mobility Microvilli - Structure - Extensions of the plasma membrane - Each cell has many microvilli - Usually 1/10^th^-1/20^th^ the size of cilia hence microvilli - Non motile - Function - Increases the cells surface area - E.g. absorptive cells of the intestine or kidney tubules Lecture 2 Histology - The technique used to study cells - The lab cut up tissues very small, look at them under a microscope and examine their features - Colours and stains are added to highlight features - Tutorial notes Activity 1 Body fluid - Intracellular - Extracellular - Intercellular - Intervascular Preparation of tissue 1. Removal of the tissue from the body via biopsy or autopsy 2. Fixation of tissue using a substance called paraformaldehyde to prevent the tissue from breaking down 3. Embedding of tissue could be wax or something frozen 4. Slicing of tissue very thin and mounting of tissue onto slide 5. Staining and viewing using a microscope Hematoxylin and eosin - Abbreviated to A&E - Nuclei are stained purple from hematoxylin because haemotoxylin attaches to the nucleic acids we find in the nucleus whereas other cell structures including the cytoplasm are stained pink from eosin Points to consider when viewing a histological image - The plane the issue has been cut in has a significant impact on how the tissue might look - The magnification of the image Primary tissues - All organs in the body contain all 4 of the primary tissues - Epithelial -\> overs - Lines all of the tubes of our body and the whole outside of our body (skin) - Connective -\> supports - Bone and cartilage - Muscle -\> movement - Contracts and causes force - Nervous -\> control - Neurons and supporting cells governing the functions of the body Epithelial tissue 1 - Also known as epithelium (pleural) - Characteristics of epithelial tissue: - Covers and protects - Covering and lining epithelium - Glandular epithelium (secretory) - Distinct cell surfaces - Free surface (top ) - Lateral surface - Basal surface a.k.a. basement membrane or basal lamina - Connects the epithelium to underlying connective tissue - Avascular (no blood supply) but inverted (has nerves) - Any nutrients or substances that the epithelium needs is diffused through the basement membrane from the connective tissue - Ability to regenerate - Constantly dividing and regenerating from the basal layer Epithelial tissue classification - Cell layers - Simple - A single layer of cells - Stratified - More than one layer of cells, often with different shapes from the lowest layers (attached to the basement membrane) to the top layers (furthest from the basement membrane) - Pseudostratified - Looks like there is more than one layer of cells when in reality it is one layer, the base of all cells sit on the basement membrane - Cell shapes - Squamous - Thin flat cells when viewed from the side and look like paving stones from the surface - Cuboidal - Cube shaped so they appear quite square in most views and usually have a large round nuclei - Columnar - Tall cells usually with an ovoid nucleus sitting towards the base of the cell - Transitional - Can change in shape from a taller to a flatter cell - Only found in the urinary system Simple squamous - A single layer of flattened cells with sparse cytoplasm - Functions: - Diffusion - Filtration - Some secretion - Some locations: - Alveoli of the lungs - Kidney glomeruli, serous membranes of the pleura, pericardium and peritoneum Simple cuboidal - One layer of cube shaped cells sitting on a basement membrane, some with microvilli or cilia - Functions: - Absorption - Secretion - Movement - Some locations: - Kidney tubules, bronchioles Simple columnar - Single layer of column-shaped or tall cells with round/oval nuclei. Some cells have cilia - Functions - Absorption - Secretion - Movement - Locations - Intestines, stomach, fallopian tubes and lungs Transitional - Can resemble stratified squamous and stratified cuboidal cells depending on its state - Function - Accommodate changes in fluid volume of the organs - Location - Urinary bladder, ureter, and upper part of urethra Stratified squamous - Basal cells are cuboidal or columnar but become progressively flatter(squarmous) as you move to the surface. There are several layers of cells - Keratinized - Non-keratinized - Functions - Protection against abrasion and loss of water - 'wear and tear epithelium' - Keratin is waterproof - Locations - Keratinized: sole of feet, palm of hands, skin - Non-keratinized: mouth, oesophagus, anus and vagina Stratified cuboidal - Several layers of cubed shaped cells, a rare tissue - Function: - Absorption - Secretion - Protection - Locations - Ducts of sweat glands, ducts of salivary glands and developing ovum Stratified columnar - Several layers of column shaped cells, a rare tissue - Function: - Secretion - Protection - Locations - Ducts of mammary glands, larynx and part of the male urethra Pseudostratified columnar - Single layer of columnar cells with differing heights - Some cells may not extend all the way to the surface - Nuclei are all over the place and cells are ciliated - Function - Secretion - Movement - Some locations - Pharynx, trachea, male sperm carrying ducts Combinations that don't exist - Simple transitional - Stratified transitional - Pseudostratified squamous - Pseudostratified cuboidal - Pseudostratified transitional Lecture 2 Connective tissue - The most abundant and widely distributed primary tissue in the body - Few cells and lots of extracellular matrix -- very diverse in structure and function - Function - Connects, binds together, supports, strengthens, protects, insulates, compartmentalises, transports and provides energy - Location - Found in all organs and parts of the body but the amount varies Composition of connective tissue 1. Cells 2. Ground substance 3. Fibres - 1 = produce the ECM - 2&3 = extracellular matrix/material (ECM) Cells of connective tissue 1. Adipose cells (adipocytes) -- fat cells - energy source and cushioning 2. Fibroblasts -- secrete connective tissue fibers and ground substance 3. Mast cells -- immunity, immune reactions 4. White blood cells (leucocytes) -- repair injury and fight off infection (immune system) 5. Macrophage -- phagocytose foreign molecules e.g. dust particles, injured cells and foreign bacteria Ground substance - Fills the space between the cells of connective tissue, and the space where fibres are suspended - Viscous substance Fibres of connective tissue - Collagen fibres: family of proteins, abundant, provides rigidity and strength, found in skin, muscles, bone and ligaments - Elastic fibres: stretch and recoil/distension, found in elastic arteries(aorta), larynx, vertebral ligaments - Reticular fibres: supporting network, very thin, highly branched, found in small blood vessels, lymph nodes, arteries and the uterus Connective tissue (proper) - Loose - Areolar - Adipose - Reticular - Dense - Regular - Irregular - Elastic Areolar connective tissue - Functions - Loose packing support and binding of other tissues - Locations - Widely distributed throughout the body - The connective tissue that epithelia of the skin rests on Adipose connective tissue - Functions - Nutrient strong ability - Shock absorption and protection - Insulation - Locations - Fat beneath the skin, surrounding kidneys, breasts, abdomen and hips Reticular connective tissue - Functions - Forms a framework to support blood cells (white blood cells, mast and macrophage cells) - Locations - Lymph nodes - Spleen - Bone marrow Regular connective tissue - Functions - Attachment - CT bundles - Locations - Tendons (bone to muscle) - Most ligaments (bone to bone) Irregular connective tissue - Functions - Provides strength and stretching capabilities in all directions (3D) - Location - Skins dermis - Fibrous covering surrounding bones, cartilages and organ capsules Elastic connective tissue - Functions - Has high recoil and strength - Location - Walls of arteries, aorta - Ligaments between spinal vertebrates Cartilage - Made of cells with a rigid matrix - Avascular and not innervated - Functions - Provides protection, Flexibility, rigidity, and capable of withstanding pressure - Types and their locations - Hyaline cartilage -- most abundant and found in the rib cage, trachea, articulating surfaces of the bones and nose - Fibrocartilage -- found in intervertebral discs and pubic symphysis - Elastic cartilage -- found in the ear and epiglottis Bone - Supports and protects body structures - Composed of cells and matrix - Osteocytes (bone cells) reside in lacune - Two types: - Spongy bone: found at the ends of long bone, sternum, vertebrate and pelvis - Compact bone: found in the shaft of long bone and makes up the outer portions of all bone Blood - Atypical connective tissue as that it does not provide support or connect anything - Mostly red blood cells (erythrocytes) and scattered white blood cells (leucocytes) and platelets (for blood clotting) - Transport for nutrients, waste d respiratory gases around the body Lecture 3 Muscle tissue - Highly cellular, well vascularised, and responsible for tension and body movement - Types of muscle - Skeletal - Cardiac - Smooth Skeletal muscle - Muscles attached to the bones of the skeleton - Heat regulation, metabolism, posture and breathing - Can regenerate after injury - Can hypertrophy in response to exercise or waste with disuse - Skeletal muscle cells are called muscle fibres or myofibers - Striated muscle - Multinucleated - Peripheral nuclei (on the edges of the tube) - Mostly under voluntary control but involuntary movements can occur such as twitching Cardiac muscle - Only found in the walls of the heart - Involuntary control - Cardiac muscle contractions: 1. Generate pressure which moves blood through the vessels 2. Change the rate and the force of contractions to meet the metabolic needs of the body -- exercise, rest and position - The heart wall consists of : 1. Epicardium (visceral pericardium): serous membrane, underlying fatty connective tissue -- contains blood vessels and nerves 2. Myocardium -- middle muscular layer, cardiomyocytes, majority 3. Endocardium -- Inner layer, endothelial lining (simple squamous epithelium) - Cardiac muscle cells are called cardiomyocytes - Striated muscle with intercalated disks - Individual cells come together and work and function together through the use of the junction - Lots of mitochondria - Under involuntary control Smooth muscle - Found mostly in the walls of hollow organs and tubes e.g. the bladder, stomach, intestines, uterus and blood vessels - Regulates the size of the organ/tube, moves content along - Blood vessels - Tunica media: smooth muscle cells arranged circularly around e blood vessel - Vasoconstriction: smooth muscle contract ecreasing the blood flow - Vaodialation: smooth muscle relaxes allowing for more blood flow - No striations - Single nucleus per muscle cell (middle of the cell) - Under involuntary control - Can regenerate Nervous tissue - Nervous system - Brain - Spinal cord - Nerves - Nervous tissue is the main component of the nervous system - Neurons (nerve cells) - Supporting cells (neuroglia) - Neurons have the ability to produce and conduct action potentials - Neuroglia act to nourish, insulate and protect nerve cells and increase productivity - Cell body (soma) contains nucleus - Dendrites (receive information) - Axon (conducting or transmitting information ) Activity 2 - Cells in a moist environment from saliva, bacteria, food - Cells in an harsh acidic environment containing enzymes - Lots of blood supply, compact skeletal muscle cells, lactic acid - Sweat, dust, keratin 3\. enzymes, intracellular fluid, water, protein, nutrients, cell organelles Organelle functions Nucleus -- tells the cell what to do (boss or brain of the cell) control centre, codes for proteins Nucleolus -- stores DNA and genetic material, produces ribosomes Mitochondria -- powerhouse of the cell, cellular respiration, ATP Ribosomes -- site of protein synthesis Lysosomes -- digestion of molecules(waste material) Rough endoplasmic reticulum -- site of protein synthesis and modification of ribosomes Smooth endoplasmic reticulum -- site of steroid, carbohydrate and lipid synthesis, detoxification of harmful substances Centrosome -- creates spindle fibres during meiosis and mitosis Golgi apparatus -- modifies, packages and distributes protein and lipid Plasma membrane -- controls what goes in and out of the cell, encloses and supports cellular contents 2\. a cell that requires lots of energy like a muscle cell, especially cardiac and skeletal muscle, kidney cells, liver cells 3\. skeletal muscle and osteoclast cells have two nuclei. They have two because they require more regulation for more functions 4\. cells in the ovaries and testes (hormones), adrenal glands (cortisol), liver (detox) 5\. secretory cells such as pancreatic beta cells (insulin), goblet cells (mucus), stomach chief cells (digestive enzymes) and plasma cells (antibodies) - Cytoskeleton - Cytosol - Cytoplasm 1. Muscular -- cardiac (pumps blood around the heart), skeletal (makes up muscles that can be consciously controlled by the brain to move the body) and smooth (found within organs that require movement like the stomach and intestines). All very compact cells Connective tissue Nervous tissue -- made up of long thin nerve cells stretching across long distances within the body to conduct nerve impulses to and from the brain. Nervous tissue can be found in the brain and spinal cord, information processing Epithelial tissue A. Nervous tissue B. Connective tissue C. Skeletal muscle tissue 1. Anchors the epithelial layer to the layers underneath Simple cuboidal, 1 layer, secretion of thyroxine and absorption 1 layer, Simple columnar, 1 layer, small intestines, uterine tubes and collecting ducts of the kidney Multiple layers, ears/nose/hands (only the skin) barrier protection and reduces water loss Simple squamous, diffusion, filtration, friction Multiple layers, throughout the urinary system Stratified squamous, non-keratinised, anus/rectum/vagina Be in motion, move materials