Dental Board Exam Reviewer 2023 PDF

DENTAL BOARD EXAM REVIEWER 2023 Dr. Mickhail Q. Francisco  PARTS OF THE CELL CELL MEMBRANE Aka “Plasma membrane” or “Cytoplasmic membrane” Semi-permeable membrane that regulates the passage of substances in and out of the cell. NUCLE...

DENTAL BOARD EXAM REVIEWER 2023 Dr. Mickhail Q. Francisco  PARTS OF THE CELL CELL MEMBRANE Aka “Plasma membrane” or “Cytoplasmic membrane” Semi-permeable membrane that regulates the passage of substances in and out of the cell. NUCLEUS Covered by bilayered membrane (phospholid bilayer) called Nuclear Envelope Contains DNA and RNA o Chromosome – thread-like structures that carry genetic information; contains a single double-stranded DNA molecule o Chromatin – material that makes up chromosomes; complex of DNA and its associated protein (DNA + Histones); “beads on string” appearance o Chromatid – chromosome copy o Sister Chromatids – chromatids that are bound to each other by a Centromere Contains the Nucleolus o Structure found within the nucleus responsible for Ribosomal synthesis QUESTIONS: 1. What is/are the function/s of histones? A. Guides the coiling of the DNA B. Guides the replication of DNA during mitosis C. Attaches sister chromatids together D. All of the above 2. Which of the following is true about somatic and sex cells? A. Both are 2n B. Both are n C. Somatic cells are 2n while sex cells are n D. Somatic cells are n while sex cells are 2n 3. 47, XY, +21 karyotype A. Edwards syndrome – male B. Downs syndrome – male C. Klinefelter syndrome – male D. Turners syndrome – female MITOCHONDRIA Powerhouse of the cell Contains folds known as Cristae Site of Kreb cycle/Citric acid cycle/Tricarboxylic acid cycle and Oxidative Phosphorylation Mechanisms for ATP Production Byproducts Glycolysis (Cytoplasm) 2 ATP, 2 Pyruvic acid, 4 Hydrogen Kreb Cycle (Mitchondria) 2 ATP, 16 Hydrogen, 4 CO₂, 2 Coenzyme A Oxidative Phosphorylation 34 ATP (Electron Transport Chain of Mitochondria) Direct Phosphorylation (Cytoplasm) 1 ATP, 1 Creatine MQFranciscoDMD 1 RIBOSOMES A non-membrane bound organelle which is responsible for Protein Synthesis Composed of rRNA that are created in the Nucleolus o Question: What are proteins made of? o Question: What are amino acids made of? Types of Amino Acids Essential Non-Essential Threonine Proline Lysine Glycine Methionine Alanine Arginine Serine Valine Cysteine Phenylalanine Aspartic Acid Leucine Glutamic Acid Tryptophan Asparagine Isoleucine Glutamine Histidine Tyrosine Types of RNA rRNA Ribosomal RNA; forms RIBOSOMES (translates the mRNA) mRNA Messenger RNA; carries genetic information of DNA; end product of TRANSCRIPTION tRNA Transfer RNA; carries amino acids to the ribosomes during TRANSLATION ROUGH ENDOPLASMIC RETICULUM Contains Ribosomes giving it a “Rough” appearance Site of protein synthesis SMOOTH ENDOPLASMIC RETICULUM Does not contain Ribosomes giving it a “Smooth” appearance Site of: o Steroid synthesis – formation of steroidal hormones like testosterone, estrogen, progesterone, etc. o Lipogenesis – process of fat formation o Detoxification of different substances (drugs, alcohol etc.) QUESTION: 1. What are the non-insulin dependent tissues? GOLGI APPARATUS - Packages and modifies the products made by the RER. LYSOSOMES Packaged products of Golgi apparatus Contains hydrolytic “Lysozymes” or enzymes Responsible for Apoptosis or “Programmed cell death” Types of Nuclear Changes during Apoptosis Kayolysis Nucleus dissolution Pyknosis Nucleus shrinks and chromatin condenses Karyorrhexis Fragmentation of the nucleus and the chromatin disintegrates MQFranciscoDMD 2 QUESTION: 1. Which of the following is considered as an active enzyme? A. Holoenzyme B. Apoenzyme C. Co-enzyme D. Co-factor CENTROSOME Holds the chromosomes during cellular division Contains pair of Centrioles made of microtubules arranged in “cartwheel pattern” CELLULAR ACCESSORIES: Microvilli o Increases surface area of a cell that increases its Absorption property o Example of location: Epithelium of Stomach to 2/3 Anus (Simple Columnar with Microvilli) Cilia o “9+2 pattern” or “9+0 patttern” arrangement of microtubules o Example of location: Upper part of respiratory tract and Fallopian tube 1. Respiratory Epithelium (Upper respiratory tract) - Pseudostratified columnar ciliated with goblet cells Flagella o Made up of axoneme o For motility of the cell and it is longer than cilia o Types of Flagella: 1. Atrichous – absence of flagellum 2. Monotrichous – single flagellum 3. Amphitrichous – flagella are present at both ends of the microorganism 4. Lophotrichous – tufts of flagella at one end of the microorganism 5. Amphilophotrichous – tufts of flagella at both ends of the microorganism 6. Peritrichous – flagella are found around the microorganism QUESTION: 1. What is Chemotaxis? 2. What initiates flagellar activity and chemotaxis? 3. Mitochondria of the sperm are located in? 4. Sperm penetrates the egg cell using? 5. The tail of a sperm cell is made up of? CELLULAR DIVISION Interphase – it is the longest phase of cellular division 1. G1 Phase “First gap phase”; cell grows and still function as usual 2. S Phase “Synthesis phase”; DNA replication; RNA synthesis 3. G2 Phase “Second gap phase”; Cells prepare for mitosis; Organelles double in number QUESTION: A cell that has already stopped from dividing is said to be in which stage of cellular division? MQFranciscoDMD 3 MITOSIS (PMAT) – Division of Somatic cells; results in 2 genetically identical daughter cells (Diploid cells) 1. Prophase Nuclear membrane and nucleolus disintegrate Chromatin coils and condenses (chromatid) and forms chromosomes Centrioles in centrosome replicates and move towards opposite poles 2. Metaphase Mitotic spindles from centrosomes attach to centromere Chromosomes ALIGN AT THE EQUATOR of the cell 3. Anaphase Chromosomes SPLIT (become chromatids) going towards opposite poles 4. Telophase Nuclear membrane reappears Cleavage furrow forms Cytokinesis – cytoplasm divides into two QUESTION: Steps 1 to 4 is also known as? MEIOSIS Division of sex cells Germ line cells (46 chromosomes) – parent cells Interphase – same as above Meiosis 1 Prophase 1 Same as mitosis QUESTION: o What is the phenomenon wherein homologous chromosomes pair during meiosis? o Sharing of DNA of two homologous chromosomes, also known as the “Crossing-over” or “Chiastmata formation” of chromosomes is called? Metaphase 1 Same as mitosis Anaphase 1 Same as mitosis, but homologous chromosomes move towards opposite poles Telophase 1 and Cytokinesis 1 Same as mitosis Cytokinesis 1 o Forms 2 UNIQUE HAPLOID daughter cells for sperm (23 chr) o Forms 1 UNIQUE HAPLOID Secondary oocyte and 1 POLARY BODY for egg cell (23 chr) Meiosis 2 – UNIQUE HAPLOID daughter cells enter Meiosis 2 (23 chr) Prophase 2 Same as above mitosis No SYNAPSIS and RECOMBINATION! Metaphase 2 Same as mitosis Anaphase 2 Same as mitosis Telophase 2 and Cytokinesis 2 Same as mitosis MQFranciscoDMD 4  Cytokinesis 2 o Forms 4 UNIQUE HAPLOID daughter cells for sperm (23 chr) o Forms 1 UNIQUE MATURE HAPLOID oocyte and 3 polar bodies for egg cell (23 chr) CELLULAR PHYSIOLOGY BODY COMPOSITION Body Fluid (Water) – 60% of body weight Proteins – 17% Fats – 15% Carbohydrates – 1% Others – 7% TYPES OF CELLULAR TRANSPORT Passive Transport Movement of molecules across the cell membrane without using ATP Types: o Simple Diffusion – Aka Passive Diffusion ▪ Movement of solutes from a higher concentration gradient to a lower concentration gradient. ▪ E.g., movement of molecules across blood vessels, gas exchange o Facilitated diffusion – aka Carrier-mediated transport since it uses carrier proteins. ▪ E.g., glucose transport across the cell membrane o Osmosis – movement of solvent across a semi-permeable membrane from low osmotic pressure to high osmotic pressure. ▪ Osmotic pressure – determined by solutes dissolved in the solution. ▪ Hypertonic – high concentrations of solute Cells in hypertonic solution results to Shrinkage ▪ Hypotonic – low concentration of solute Cells in hypotonic solution results to Cell Bursting ▪ Isotonic – solution has same solute concentration of the body cells QUESTION: 1. What is the most important protein that increases the osmotic pressure of the blood? 2. Saliva in the Oral Cavity is HYPERTONIC, HYPOTONIC or ISOTONIC? Active Transport Movement of molecules from low concentration gradient to high concentration gradient that uses ATP Example: o Na-K pumps (muscle) and Proton pumps (stomach) o Bulk Transports: ▪ Exocytosis – substance exits a cell via vesicles ▪ Endocytosis – substance enters a cell placing it in a vesicle ELECTROLYTES ION Extracellular Fluid (ECF) Intracellular Fluid (ICF) Sodium (Na+) Most numerous cation in Least numerous cation in ICF ECF Potassium (K+) Least numerous cation in Most numerous cation in ICF ECF MQFranciscoDMD 5  Chlorine (Cl-) Most numerous anion in Least numerous anion in ICF ECF Bicarbonate (HCO3-) Least numerous anion in ECF; Most important BUFFER of the blood plasma Phosphate (PO4-) Most numerous anion in ICF; Acts as a buffer in blood plasma BODY TISSUES TYPES OF BODY TISSUES 1. Epithelial – lines and covers body surfaces and body cavities. 2. Connective – protect, support and bind body tissues together. 3. Muscular – for movement. 4. Nervous – receives stimuli and conducts impulses. CELLULAR JUNCTIONS - connection between plasma membranes or cell membranes of cells. CELL JUNCTION FUNCTION Desmosomes *Aka “Spot-weld-like or Macula adherens” *Attaches SAME CELLS together *Example of location: EPIDERMIS and CARDIAC MUSCLE cells. Hemidesmosomes *Attaches DIFFERENT CELLS together *Example of location: >Between EPIDERMAL CELLS and BASEMENT MEMBRANE >Between JUNCTIONAL EPITHELIUM and TOOTH SURFACE Gap Junctions *Forms a bridge that allows ion diffusion between cells. *Example of location: NERVE CELLS and CARDIAC MUSCLE cells. Tight Junctions “Zona occludens”. Prevents leaking of substances. Adherens Junctions “Zona adherens” Prevent separation of epithelial cells during intestinal contraction. GLANDULAR EPITHELIUM a. Endocrine glands - secrete hormones towards blood. Doesn’t have ducts. E.g., Pituitary gland, Thyroid gland, Pancreas b. Exocrine glands – secrete products onto the external surface of the body. Contains ducts. E.g., Salivary gland; mammary glands, sebaceous glands and Pancreas Functional Classification of Exocrine Glands Merocrine Releases “packaged” vesicles. Salivary glands Apocrine Part of cell will be pinched-off together with vesicles. Mammary glands Holocrine Cell ruptures and releases contents. Sebaceous glands MAJOR SALIVARY GLANDS Parotid Gland Largest (size) with a Pyramidal shape Located anteroinferior to External Acoustic Meatus Stensen’s duct – Opens opposite Maxillary 2nd molar Secretion: Purely SEROUS Submandibular Gland Second largest (size) Produces GREATEST VOLUME of saliva Wharton’s duct – Opens in sublingual caruncle MQFranciscoDMD 6  Secretion: Mixed - Mostly SEROUS Sublingual Gland Smallest The only unencapsulated major salivary gland Bartholin’s duct Rivinu’s duct Secretion: Mixed – Mostly MUCOUS Minor Salivary Glands Glands of Von Ebner Located in the circumvallate papillae; purely serous Palatine Glands posterolateral border of palate; purely mucous Buccal and Labial Glands purely mucous Glands of Blandin-Nuhn anterior lingual; mixed mostly serous QUESTION: 1. Basket cells or Myoepithelial cells are found in? 2. Best example of unicellular gland? BASIC TYPES OF PROTEINS IN THE BODY Collagen o The most numerous protein in the body. o Provides strength for the tissues. o Basic types of collagen: ▪ Type I – Most abundant. Seen in Dermis, Bone, Pulp, Dentin, Cementum, etc. ▪ Type II – seen in Cartilage. ▪ Type III – seen in Reticular fibers and tissues. ▪ Type IV – Basement membrane ▪ Type V – hair and placenta Elastin – highly elastic protein Keratin – most numerous protein in EPIDERMIS Albumin – most numerous protein in the BLOOD; determines osmotic pressure QUESTION: 1. What is the most numerous PROTEIN IN ENAMEL? 2. What is the disease where the patient has EXCESSIVE ELASTIC FIBERS? 3. What is the disease where the patient has DEFECTIVE COLLAGEN FIBERS resulting to flexibility of tissues made up of collagen? 4. What is the disease where the patient has DEFICIENCT COLLAGEN FIBERS? MQFranciscoDMD 7  CONNECTIVE TISSUE CELLS 1. Fibroblasts – fiber-forming cells 2. Macrophages – monocytes outside the circulatory system; differentiated monocytes; they are formed in the bone marrow Reticuloendothelial or mononuclear phagocyte system CELL TYPE LOCATION FUNCTION Monocyte Blood/Bone Marrow Precursor of macrophages Macrophage Connective Tissues, lymphoid Production of cytokines, chemotactic organs, lungs, bone marrow, factors, and inflammatory molecules. pleural and peritoneal cavities Antigen-presenting cells Kupffer Liver (perisinusoidal) Same as macrophage Microglia CNS Same as macrophage Dust cells/Alveolar macrophages Pulmonary alveoli of lungs Same as macrophage Sinus Histiocytes Lymph nodes Same as macrophage Histiocytes (Tissue macrophages) Connective Tissue Same as macrophage Langerhans cells Epidermis Antigen-presenting cells Dendritic cells Lymph nodes, spleen Antigen-presenting cells Osteclasts Bone Digestion of bone Epitheloid cells and Langhans giant cells Granuloma (e.g. TB) Digestion of foreign bodies (fused epitheloid cells) Hofbauer cells Placenta Prevents transmission of pathogens from mother to fetus Intraglomerular Mesangial cells Kidney Regulates glomerular filtration 3. Adipocytes – Fat cells or Adipose cells. 4. Cartilage – They don’t have direct blood supply and nerve supply. Types of Cartilagenous Growth: i. Interstitial – growth within the tissue; happens only when a cartilage is young and pliable, during childhood and adolescence; This is due to cellular division of cartilage cells. ii. Appositional – growth at the outer surface; continuous through adolescence. This is due to addition of bony matrix at the surfaces of the tissue. Cartilage Type Characteristic Example of Location Hyaline Cartilage *Most numerous; weakest *Ends of bones that forms joints *Made up of chondrocytes + few *Nose collagen fibers *Fetal Skeleton *Trachea *Bronchial tree *Synchondrosis and etc. Elastic Cartilage *Least common type *Pinna *Made up of chondrocytes + *Epiglottis elastic fibers *Eustachian tube Fibrocartilage *Strongest type *Meniscus of knee joint and TMJ *Made up of chondrocytes + *Symphisial Joints thick collagen fibers 1. Symphysis Menti 2. Symphysis pubis 3. Manubriosternal joint 4. Intervertebral disc MQFranciscoDMD 8  5. Bone MAIN TYPES OF CHARACTERISTICS BONE Primary Bone *Aka woven bone or immature bone *Randomly arranged cells and fibers *Less calcified Secondary Bone *Aka lamellar bone or mature bone *Parallel bundles of collagen *Heavily calcified *Has 2 subtypes: Spongy bone and Compact bone Types of Secondary bone Spongy bone *Aka spongy bone, cancellous bone or trabecular bone *Made up of trabeculae Compact bone *Strongest type of bone *Functional unit is known as Haversian system or Osteon QUESTION: 1. This is the only type of growth that happens in bone tissue A. Interstitial B. Appositional C. Both D. None of the above 2. What structure is seen at the central portion of the osteon? 6. Blood Plasma (55%) – mostly water (around 95%) and other substances Formed Elements (45%) – blood cells (RBC, WBC and Platelets) 7. Formed Elements of Blood White blood cells – Leukocytes (4,500 to 11,000 cells/microliter of blood) i. Granulocytes (BEN) Basophil ❖ Least numerous; releases Histamine and Heparin ❖ Dark blue/purple granules ❖ Bilobed or S-shaped nucleus ❖ Several months Eosinophil ❖ Kills parasites and modulates inflammation ❖ Bilobed nucleus ❖ Red/dark pink granules ❖ 1 to 2 weeks Neutrophils ❖ First line of defense of WBCs (kills and phagocytose microorganisms) ❖ Faint/light pink granules ❖ 3- 5 lobes nucleus ❖ 1 to 4 days MQFranciscoDMD 9  ii. Agranulocytes Monocyte ❖ Precursors of macrophages and other mononuclear phagocytic cells ❖ Largest leukocyte ❖ Single nucleus (indented/C-shape/Kidney-shape) ❖ Hours to years Lymphocyte ❖ Smallest leukocyte with spherical nucleus ❖ Hours to years ❖ Important for adaptive immunity i. B-lymphocyte – matures in bone marrow ii. T-lymphocyte – matures in thymus 1. CD4 – T helper 2. CD8 – Cytotoxic 3. NK cells or Natural Killer cells – special type of CD8 REMEMBER: Never Let Monkey Eat Bananas (mnemonic for most numerous to least numerous WBC) QUESTION: In hematology, a “Shift to the left” means? Red blood cells – Erythrocytes i. Most numerous cells in the body. Females: 4-5 million cells/microliter of blood Males: 5-6 million cells/microliter of blood ii. 120 days life span iii. 7 days maturity iv. Contains Hemoglobin that allows it to carry oxygen QUESTION: 1. Universal donor? 2. Universal recipient? 3. Most important mineral for RBC production? Platelets – Thrombocytes i. Determines fragility of capillaries ii. 10 days lifespan iii. Normal value: 150,000 to 450,000 cells/microliter of blood QUESTION: Capillary fragility test is also known as? 8. Plasma Cells – produces antibodies or immunoglobulins; has Clockface or Cartwheel nucleus IMMUNOGLOBULINS/ CHARACTERISTIC ANTIBODIES IgG Most numerous; produced by the body when there is infection IgA Body fluids and Gastrointestinal tract IgM 1st line of defense of Immunoglobulins IgE Active during allergic rxns; parasitic infections IgD Unknown function MQFranciscoDMD 10  9. Lymphatic System Functions: i. Absorbs fluids that are not absorbed by the veins. ii. Filters the fluid in the circulatory system Fluids within lymphatic vessels are called Lymph Lymphatic organs i. Primary – Bone Marrow and Thymus ii. Secondary – Spleen, tonsils, and lymph nodes Important structures in Lymphatic System: i. Lymphatic ducts – these are the largest lymphatic vessels in the human body. They carry lymph at the junction of Internal Jugular Vein and Subclavian vein Left lymphatic duct – largest lymphatic duct Right lymphatic duct ii. Cisterna chyli – dilated sac at the lower end of thoracic duct that drains lymph from intestinal and lumbar area. QUESTION: 1. Red pulp of the spleen contains? 2. White pulp of the spleen contains? REMEMBER: Capillary Dynamics o Oncotic or Colloid Osmotic Pressure – form of osmotic pressure exerted by proteins in the blood plasma or interstitial fluid o Hydrostatic pressure – force generated by the pressure of fluid inside or outside of a capillary against the capillary wall. Fluids In (from interstitium to capillaries) Fluids Out (from capillaries to interstitium) Interstitial Fluid Hydrostatic Pressure Blood Hydrostatic Pressure Blood Oncotic Pressure Interstitial Fluid Oncotic Pressure INTEGUMENTARY SYSTEM Largest system of the body 2 parts: o Epidermis o Dermis EPIDERMIS Keratinized Stratified Squamous epithelium 4 cell types: 1. Keratinocytes ▪ most numerous cells in epidermis ▪ produces keratin – epidermis 2. Melanocytes ▪ Produces the pigment melanin (yellow-red or brown-black) ▪ Originated from embryonic cells known as neural crest cells ▪ Nucleus is located away from UV rays 3. Langerhans cells – macrophage of epidermis 4. Merkel cells ▪ least numerous in epidermis ▪ located in Stratum basale in epidermis where it contacts a sensory neuron called “Merkel (tactile) discs” ▪ Merkel cell together with its Merkel discs – detect “Touch” sensations. MQFranciscoDMD 11