Exam 6 Study Guide PDF

# Study Guide - Cumulative, histology portion ## Cell Biology - **Compare and contrast the processes of necrosis and apoptosis.** ### Necrosis - pathological, occurs in response to acute injury - cells ruptured by injury and release digestive enzymes that damage nearby cells and trigger inflamma...

# Study Guide - Cumulative, histology portion ## Cell Biology - **Compare and contrast the processes of necrosis and apoptosis.** ### Necrosis - pathological, occurs in response to acute injury - cells ruptured by injury and release digestive enzymes that damage nearby cells and trigger inflammatory response and swell - burst and release enzymes and inflammatory signals ### Apoptosis - deliberate (not accidental) - genetically-programmed cell suicide - can be normal or developmental (fetal cells removed) - doomed cell receives chemical signal that turns on genes to initiate and complete apoptosis (Caspase Enzyme Cascade) - pyknosis (condense chromatin), cell shrinks (loss of cell-cell contact), cytoplasmic budding (membrane-bound fragments), apoptotic bodies (cell fragments with nuclear material) - NO inflammatory response bc cell slowly self-destructs - phagocytes clean up apoptotic debris ## Epithelium & Glands - **Relate the structure and functions of each type of epithelium to its location in the body.** ### Simple Squamous - width greater than height, flat nucleus, covering - **Location:** - line body cavities and organs (mesothelium) - line blood and lymph vessels (endothelium) - thin loop henle (kidney) - vestibular membrane in cochlea - alveoli in lung - bowman's capsule in renal corpuscle (kidney) ### Simple Cuboidal - spherical and central nucleus, width, depth, height are same - **Location:** - small ducts exocrine glands - thyroid gland (line thyroid follicle) - germinal epithelium (ovary) - choroid plexus of ventricles (brain) - kidney tubules (DCT and PCT) ### Simple Columnar - taller than width, oval/elongated nucleus - **Location:** (found stomach and down) - stomach - small intestine - large intestine - gall bladder - uterus ### Stratified Squamous - **1. Keratinized Stratified Squamous** - dead squamous cells (keratinocytes) @ surface = form waxy protection against dryness, bacteria, and friction - dead cells @ surface have NO NUCLEI, continually shed off - **Location:** - epidermis of skin (thicker on palms of hands and feet) - **2. Non-Keratinized Stratified Squamous** - squamous surface cells HAVE NUCLEI and are still living - **Location:** - moist surfaces - oral cavity, esophagus, anus, vagina ### Stratified Cuboidal - circle nucleus, few layers of cuboidal cells - **Location:** - sweat glands - larger ducts of exocrine glands ### Stratified Columnar - lower layers = cuboidal cells, surface layers = columnar - **Location:** - largest ducts of exocrine glands - portion of male urethra - transition sites between stratified squamous and pseudostratified ### Pseudostratified - appear stratified bc nuclei are observed at different levels - but is not - consists of: columnar cells (has goblet cells) and basal cells - all cells rest @ basement membrane, only columnar cells reach free surface - **Location:** - trachea and bronchi of respiratory tract - efferent ductules, epididymis, vas deferens of male reproductive tract ### Transitional - like stratified cuboidal but surface cells change between squamous (distended) and cuboidal (contracted) shape - **Location:** - urinary system only (ureters, urinary bladder, portions of urethra) ### Specialized (derived from embryonic epithelial sheets) - **Neuroepithelium:** organ of corti or olfactory epithelium - **Pigmented epithelium:** retina - **Germinal epithelium:** seminiferous tubules of testes - **Myoepithelium:** contractile cells of glands ## Connective Tissue - **Describe the classification of the different types of adult connective tissue proper based on fiber type, density, arrangement and location.** ### Adult CT: **CT proper** - **Loose CT (high cell:fiber)** - fibroblasts, mast cells, adipose cells, macrophages, plasma cells - **ECM** - ground substance with fibers - collagen (thick and wavy) - elastic (thin, straight and branching) - **Location:** - around muscles, organs, blood vessels, nerves, subcutaneous region (deep) - beneath epithelia of GI and respiratory tracts - **Dense CT (lower cell:fiber)** - **Dense Regular** - mostly fibers with some ground substance and cells - arranged in dense parallel bundles of collagen to give strength in ONE DIRECTION - **Location:** - tendons - attach muscles to bone, tendons surrounded by epitendineum, tendons divided into fascicles by peritendineum, groups of fibers surrounded by fibroblasts and little CT endotendineum - ligaments - short tendon-like structures bone to bone - aponeuroses - broad flat-tendon like structure that attach muscle to bone - enthesis - point where tendons, ligaments, fascia attach to bone - **Dense Irregular** - collagen fibers arranged in large bundles in different directions to give lots of strength - fibroblasts scattered between bundles of collagen fibers - mast cells, macrophages, blood vessels - some elastic and reticular fibers present - **Location:** - fibrous capsules of organs - deep fascia - dermis - periosteum of bone - perichondrium of cartilage - **Reticular CT (lower cell:fiber)** - fibroblasts (reticular cells), Type 3 collagen (reticular fibers), macrophages, ground substance - **Location:** (organs with lots going in/out) - liver - bone marrow - lymphatic tissues - cardiovascular system - lungs - **Elastic CT (lower cell:fiber)** - **Dense Regular Elastic** - branching elastic fibers with sparse collagen fibers - elastic fibers arranged in parallel - sheets of elastic tissue - ligamentum flava, elastic fibers synthesized by fibroblast - fenestrated membranes - large arteries (tunica media), elastic fibers synthesized by smooth muscle cells ## Nervous Tissue - **Describe the following: Neuron Cell Body, Dendrites and Axon, Classification of Neurons, Synapses & Neurotransmitters.** ### Neuron Cell Body - soma / perikaryon - **Nissl substance:** free ribosomes in RER in basophilic clumping, extend thru cell and dendrites but NOT INTO AXON - **Microtubules and neurofilaments:** networks in cytoplasm for intracellular transport and structural integrity - **Lipofuscin granules:** residues lysosomal activity - **Mitochondria, lysosomes, golgi, selective cell membrane** ### Dendrites - transmit impulses TOWARD cell body - single or multiple processes - increase receptive area - NO golgi app ### Axon - transmit impulses AWAY from cell body - only 1 axon per neuron, but can give off collaterals - arise from axon hillock (generate impulse) - lots of microtubules, neurofilaments, mitochondria - NO nissl substance or golgi - telodendria = terminal branches ### Neurons - **Characteristics:** - irritability (reception), conductivity (transmission) - **1. Bipolar neuron:** - special senses = olfactory epithelium (CN1), retina (CN2), vestibulocochlear ganglion (CN8) - **2. Pseudounipolar neuron:** - only found in development - can be in adult - have 1 process that bifurcates with one on afferent function (dendritic) and efferent (axon) - in ganglia of CN 5, 7, 9, 10 and spinal or dorsal root ganglia - **3. Multipolar neuron:** - multiple dendrites + 1 axon (most common) - **Golgi type 1:** - axons project from 1 region CNS another; or from CNS periphery - cerebral cortex (pyrimidal cells) - cerebellar cortex (purkinje cells) - lower motor neurons in motor nuclei of CN 3, 4, 5, 6, 7, 9, 10, 11, 12 and ventral horn of spinal cord (alpha motor neurons or ventral horn cells) - autonomic ganglia (visceral motor) - **Golgi type 2:** - axons usually stay in 1 region CNS - intermediate zone of spinal cord = interneurons (in dorsal horn, connect signal to response) ## Synapses - synapses allow neuron communication with effector cells - for transmission of chemical message due to AP - **Presynaptic membrane:** synaptic vessels with NT - **Synaptic cleft:** space btw 2 neurons, or neuron and effector cell - **Postsynaptic membrane:** receptor mediated ion channel - axodendritic, axosomatic, axoaxonic ## Neurotransmitters - molecules released @ presynaptic membrane and activate receptors on postsynaptic membrane - ACh or cholinergic - AAs (glutamate, GABA, aspartate, glycine) - Biogenic Amines (NE or adrenergic, Epi, serotonin and dopamine) ## Adipose Tissue & Cartilage - **List the types of cartilage and where they are found in the body.** ### Hyaline Cartilage - **ECM:**- smooth appearance (glassy), type 2 collagen and ground substance, mostly H2O with proteoglycans (GAGs: hyaluronic acid, chondroitin sulfate, keratan sulfate) - **Chondrocytes:**- oval/round shape, basophilic cytoplasm, single cell in lacunae (farther apart), territorial matrix - **Perichondrium:**- outer fibrous layer (dense irregular CT), inner cell layer (chondrogenic cells), articular cartilage has NO PERICHONDRIUM ### Elastic Cartilage - **ECM:**- same as hyaline but has Elastic Fibers - **Chondrocytes:**- same as hyaline (lacunae closer together) - **Perichondrium:**- same as hyaline ### Fibrocartilage (always next to hyaline cartilage) - **ECM:**- type 1 collagen (tensile strength), low concentration of proteoglycans and H2O - **Chondrocytes:**- same as hyaline but located in abundance of collagen fibers (looks like lacunae in dense irregular CT- - **Perichondrium:**- NONE ## Muscle Tissue - **Describe the structure of skeletal muscle. Describe the blood supply and innervation of skeletal muscle.** ### Skeletal Muscle - **Striated, voluntary** - **Skeletal muscle cells:**- also called muscle fibers - **Endomysium:**- delicate CT around individual fibers - **Perimysium:**- CT surround fascicle (group of fibers) - **Epimysium:**- dense irregular CT, surround entire muscle - **Blood supply:**- derived from a couple arteries - **Innervation:** (both course in 1 nerve) - **Motor innervation:**- from lower motor neurons in brainstem and lower motor neurons in spinal cord (a-motor neurons or ventral horn cells) - **Sensory innervation:**- pseudounipolar neurons in dorsal root ganglia (and some CN ganglia). Peripheral processes connects to muscle spindles and Golgi tendon organs ## Bone Tissue - **Identify the cells found in bone (osteoblasts, osteocytes, osteoclasts) and describe the morphological appearance and function of each.** ### Osteoblasts - originate from osteogenic cells (osteoprogenitor) - cuboidal cell, basophilic cytoplasm, lots RER and Golgi - single layer on surface of developing bone - PTH activates - **Function:** secrete osteoid (procollagen [type 1], proteoglycans/GAGs, non-collagen proteins) - osteocalcin (binds hydroxyapatite crystals) - osteonectin (type 1 collagen hydroxyapatite) - bone sialoprotein (osteoblast ECM via integrins) - osteopontin (osteoclast ECM via integrins) - initiate and control mineralization - osteoid formed, osteoblasts secrete Ca into ECM - alkaline phosphatase hydrolyzes esters for free Phosphate to bind Ca = form hydroxyapatite crystals - osteoblasts stimulated by: Vit D, estrogen, IGF-1 ### Osteoclasts - large, multinucleated, acidophilic cytoplasm - derived from bone marrow (monocytes) - calcitonin inhibits - **Function:** bone resorption - active osteoclasts: - sealing zone = become active (ruffled border appears) - Howship's lacuna - acidified vesicles - cathepsin K (break down exposed organic matrix) ### Osteocytes - osteoblasts that become enclosed by ECM - reduced organelles - resides in lacuna - have cytoplasmic processes that extend into canaliculi (neighbor communication via gap junctions) - **Function:** maintain bone matrix ## Integument - **Describe the location, contents, and characteristics of the layers of the epidermis in thick skin and thin skin.** ### Stratum Basale - deepest - single layer cuboidal, anchored by hemidesmosomes - mitotic layer - keratinocytes start cycle of proliferation and maturation - melanocytes (protect nucleus from UV radiation) and merkel cells (mechanoreceptor cells, numerous in fingertips, discriminative touch, connected to keratinocytes by desmosomes) ### Stratum Spinosum - several layers cell layers, connected to each other by desmosomes - tensile strength - prominent nuclei, basophilic (from keratin proteins) - keratohyalin granules - langerhans cells (APC, present Ag to T lymphocytes, no desmosomes so can move around) and lymphocytes present ### Stratum Granulosum - 2-5 cells thick, most superficial layer of non-keratinized cells - many basophilic keratohyalin granules (overfill cells and rupture) release hydrophobic glycophospholipids = make waterproof ### Stratum Lucidum - ONLY THICK SKIN - few layers dead/dying cells, appear translucent from acidophilic stain - no nucleus ### Stratum Corneum - shed continuously - new cells formed in stratum basale and pushed up (turnover 25-50 days) - flattened dead cells without nuclei are filled with soft keratin (squames) - desquamation = occurs in outer layers as desmosomes break down ## Histology of Lymphoid - **Describe the thymus in terms of its structure (including capsule, cortex, medulla, Hassal corpuscles) cells present (immune cells, epithelial reticular cells, thymocytes), and functions** ### Thymus - primary lymphoid organ, in superior mediastinum - **Capsule:** dense irregular CT - **Cortex:** stains dark bc of lots of lymphocytes, contain epithelio reticular cells (form network around lymphocytes, lymphocyte maturation) - **Medulla:** loose network epithelio reticular cells and fewer lymphocytes, lots of macrophages to phagocytose nonfunctional cells - **Hassal corpuscles:** concentrically arranged epithelio reticular cells, in medulla, hallmark of thymus ### Cells in Thymus - **Immune cells:** - **Epithelial reticular cells:** present self-antigens to lymphocytes, in cortex where immature T lymphocytes mature into immunocompetent T cells - **Thymocytes:** ### Functions of Thymus - Where immature T lymphocytes mature into immunocompetent T cells ## Histology of Blood - **Define hematocrit.** - Hematocrit: 36-53% of blood volume of RBC. Measure of % of RBC in blood ## Histology of Circulatory System - **Compare, Identify and describe the histological structure of elastic and muscular arteries and arterioles and compare, identify and describe the histological structure of medium and large veins and venules.** ### Elastic (large) arteries - **Location:** aorta, pulmonary arteries, brachiocephalic artery, common carotid arteries, subclavian arteries, common iliac arteries - **Tunica intima:** thin internal elastic lamina, endothelium and BM - **Tunica media:** many sheets fenestrated elastic tissue btw smooth muscle - **Tunica adventitia:** thin external elastic lamina, vasa vasorum, longitudinal collagen fibers ### Muscular (medium) arteries - **Contract and relax** to regulate blood flow to tissues and organs. - **Tunica intima:** endothelium and BM, subendothelial CT, prominent internal elastic lamina - **Tunica media:** lots layers of circular smooth muscle, some elastic fibers, collagen fibers, ground substance - **Tunica adventitia:** prominent external elastic lamina, loose CT, vasa vasorum, longitudinal collagen ### Arterioles - **Tunica intima:** subendothelial CT - **Tunica media:** 1-2 layers, very little elastic, collagen, and ground substance - **Tunica adventitia:** thin layer loose CT, NO external elastic lamina ### Medium Veins - **Tunica intima:** thin layer subendothelial CT, has internal elastic lamina - **Tunica media:** 3+ layers circular SM - **Tunica adventitia:** well developed, external elastic lamina present (not visible), some elastic fibers and ground substance ### Large Veins - **Tunica intima:** subendothelial CT, has internal elastic lamina - **Tunica media:** smooth muscle with irregular orientation, NO elastic fibers - **Tunica adventitia:** external elastic lamina present (not visible), wide bundles longitudinal smooth muscle, vasa vasorum ### Venules - **Tunica intima:** NO subendothelial CT, NO internal elastic lamina - **Tunica media:** 1-3 layers of circular smooth muscle - **Tunica adventitia:** CT thicker than tunia media ## Histology of Respiratory System - **Compare and contrast the histological structures of the trachea, bronchi, bronchioles, respiratory bronchioles, and alveolar ducts.** ### Trachea - from larynx primary bronchi @ sternal angle of louis - **Mucosa:** - pseudostratified ciliated epithelium - ciliated columnar cells, goblet cells, basal cells, DNES (kulchitsky cells) - lamina propria - loose CT with serous/mucous and MALT - elastic lamina - **Submucosa:** - dense irregular CT - serous/mucous glands, MALT, large venous sinuses - **Hyaline cartilage rings (C shaped)** - C shaped hyaline rings - contraction of trachealis muscle - reduces diameter and assists in coughing ### Bronchi - **Mucosa:** - ciliated pseudostratified - lamina propria of loose CT with MALT, serous/mucus glands - elastic lamina - **Submucosa:** - dense irregular CT - fewer glands, some MALT - **Cartilage support:** - C shaped hyaline cartilage rings ### Primary Bronchi - **Mucosa:** Ciliated pseudostratified epithelium, lamina propria, elastic lamina - **Submucosa:** Dense ir ct with few glands and some MALT - **Cartilage support:** C-shaped hyaline cartilage rings ### Secondary Bronchi - **Mucosa:** ciliated pseudostratified to simple columnar, thinner lamina propria, complete muscularis mucosa (no elastic lamina) - **Submucosa:** fibroelastic connective tissue with sparse glands - **Cartilage:** Flattened interconnecting plates of hyaline cartilage ### Tertiary Bronchi - **Mucosa:** ciliated simple columnar epithelium, thinner lamina propria containing elastic fibers, MALT, complete muscularis mucosa - **Submucosa:** Fibroelastic connective tissue with few glands - **Cartilage Support:** Few hyaline cartilage plates like islands ### Bronchioles (terminal) - **Mucosa:** - ciliated simple columnar ciliated cuboidal - clara cells replace goblet cells - DNES (kulchitsky cells) still present - no glands - complete muscularis mucosa - **Submucosa:** - loose CT with elastic fibers - no glands - cartilage support: none ### Respiratory Bronchioles - **Mucosa:** - ciliated simple cuboidal - clara cells - alveoli (simple squamous) - very thin lamina propria - no muscularis mucosa but has some bundles of smooth muscle ### Alveolar Ducts - **Mucosa:** - low cuboidal mostly type 1 alveolar cells (simple squamous) - little lamina propria - smooth muscle knobs @ opening ## Histology of Digestive System - **Identify and describe the function of the cell types: a. Parietal, b. Chief, c. Enteroendocrine, d. Paneth, and e. Enterocytes and Describe the histological structure of the gastrointestinal-associated glands, including the liver, gall bladder, and exocrine pancreas.** ### Parietal cells (oxytic cells) - large, round, acidophilic cytoplasm - central/basal located nucleus - secrete gastric acid (HCl) and intrinsic factor (need for B12 absorption) - mostly in neck and upper segment gastric gland ### Chief cells (peptic / zymogenic cells) - basophilic cytoplasm - basally located nucleus - secrete pepsinogen (pepsin hydrolyzes proteins) - located in base of glands ### Enteroendocrine cells (neuroendocrine / DNES cells) - in base of glands - secretes = Gastrin (in pyloris), Secretin, CCK, Somatostatin ### Paneth cells - base of crypts - secrete antimicrobial proteins in mucus blanket ### Enterocytes - surface absorptive cells - simple columnar ### GI-associated glands - **Esophageal gland:** In submucosa of the esophagus. Contain serous and mucus cells - **Gastric gland:** simple branches tubular. In the mucosa of the stomach. Contain parietal cells, chief cells, stem cells, DNES cells, Mucus neck cells - **Cardiac glands:** simple coiled tubular glands in the mucosa of the cardiac region of the stomach. Contain few DNES and parietal cells with no chief cells - **Intestinal glands:** Located in the mucosa of the small intestine. Contain paneth cells, DNES, Enterocytes, Goblet cells - **Brunner's Gland:** Located in the submucosa of the duodenum ### Liver - surrounded by Glisson's capsule - Arranges in hepatic lobules which is the functional unit - Blood flow from the portal vein and hepatic artery through sinusoids - Cells include hepatocytes ### Gall Bladder - Stores, concentrates, and releases bile - **Mucosa:** simple columnar - **Submucosa:** smooth muscle arranged longitudinally, circularly, and obliquely - **Serosa** - **Bile** is released in response to CCK or vagus nerve stimulation - **Mucosa:** tall simple columnar, lamina propria of loose CT, forms folds when not distended - **Muscularis externi:** smooth muscle in longitudinal, circular, and oblique layers (no distinct layers) - **Serosa / adventitia** ### Exocrine Pancreas - makes pancreatic enzymes, bicarbonate ions, water into duodenum thru Common Bile Duct - **Serous alveoli** make up secretory units - Exocrine component secretes pancreatic enzymes, bicarbonate ions, and water into the duodenum through common bile duct. Secretory units are made up of serous alveoli and serous cells ## Histology of Urinary System - **Identify and describe the histological structure and location of the components of a uriniferous tubule.** ### Uriniferous Tubule - fundamental unit of kidney - **Made of Nephron + Collecting Duct** ### Nephron - renal corpuscle, PCT, loop of henle, DCT - **1. Cortical nephron:** in outer portion of cortex, Short loop of Henle - peritubular capillary network portal system - **2. Juxtamedullary nephron:** in cortex next to medulla, has Long loop of Henle - Vasa recta portal system ### PCT - First portion and most convoluted. Simple cuboidal epithelium that strains darker in a view of the cortex. Designed for reabsorption ### Loop of Henle - **Descending thick limb:** similar to pct - **Thin loop:** simple squamous epithelium found in cross sectionally images in renal medulla - **Ascending thick limb:** similar to DCT - Can see interstitial cells in a longitudinal section ### DCT - Found in the cortex - Cells are much less acidophilic. Stain lighter in the cortex of the kidney - **Macula Densa:** modified region of DCT which is part of the juxtaglomerular apparatus ### Collecting Duct - Simple cuboidal in the cortex and near the renal pyramid becomes the tall simple columnar. Several of these will enter a papillary duct which opens into the renal papillae into a minor calyx ## Histology of Male and Female Reproductive - **Identify (LM) and describe the structure and function of Sertoli and Leydig cells and Describe the general features of follicle development.** ### Sertoli cells - Removes excess cytoplasm during maturation phase - Columnar cells that extend from basement - Clear and oval nucleus with prominent nuclei - Embedded with spermatogenic cells - **1. Protective/supportive:** form blood testis barrier - divides seminiferous epithelium into Basal and Luminal compartment - also supply plasma factors for growth and differentiation - **2. Phagocytic:** phagocytize residual cytoplasm shed by spermatids - **3. Secretory:** secretes ABH to bind to testosterone to Increase levels for spermatogenesis. Also secretes inhibin that inhibits FSH release - **Stimulated by FSH from Ant Pituitary** ### Leydig cells - in loose CT between seminiferous tubules - eosinophilic cytoplasm - inactive until puberty - stimulated by LH to secrete testosterone ### Follicle Development - Develop under influence of Activin secreted by primary oocyte, FSH secreted by pituitary gland and growth factors - **1. Follicular cells granulosa cells** (cuboidal columnar and stratified) - **2. Zona pellucida forms** - glycoprotein layer between primary oocyte and granulosa cells - **3. Theca folliculi forms** - then further divides into **Theca Interna** (secrete androstenedione which is converted into estrogen by granulosa cells) and **Theca Externa** - **4. Fluid filled spaces with liquor folliculi form and antrum forms** - **5. Cumulus oophorus surrounds primary oocyte** (zona pellucida and primary oocyte are now contained in cumulus oophorus)