Histology Past Paper PDF

URINARY SYSTEM NEPHRON Paired kidneys and ureters - Structural and functional unit of kidney Urinary bladder Renal corpuscle (malpighian corpuscle) Urethra...

URINARY SYSTEM NEPHRON Paired kidneys and ureters - Structural and functional unit of kidney Urinary bladder Renal corpuscle (malpighian corpuscle) Urethra Glomerulus + bowman’s capsule Functions Renal tubules 1. Eliminate waste through urination Proximal convoluted tubule 2. Regulate blood volume, ion concentration, Loop of Henle and acid-base balance Distal tubule 3. Regulates RBC production by secretion of Collecting tubule erythropoietin Vascular pole 4. Excrete bioactive substances - Afferent and efferent arterioles enter and exit 5. Secretes renin to regulate blood pressure Urinary pole 6. Converts vitamin D3 in the skin to 1,25 - Proximal convoluted tubule begins dihydroxyvitamin D3 or calcitriol (active form) GLOMERULUS 7. Undergo gluconeogenesis during starvation - Made up of fenestrated glomerular capillaries KIDNEYS Mesangial matrix - Retroperitoneal organ found in the superior - Space between glomerular capillaries lumbar area - Similar to basement membrane - Right kidney lower than the left Mesangial cells - Enveloped by fibrous capsule - Stellate cells most numerous in vascular pole Hilus (gateway to renal sinus) - Capable of phagocytosis - Medial border where renal artery enters and BOWMAN’S CAPSULE renal vein and ureter exit - Double-walled sac encapsulating glomerulus Renal cortex (outer layer) Visceral layer (inner wall) Renal medulla (inner layer) - Lined by podocytes (stellate cells with - contains renal columns, renal papilla, minor cytoplasmic processes) calyx, and major calyx Parietal layer (outer wall) Renal papilla or apex - Lined by simple squamous epithelium - Tip of renal pyramids Bowman’s space (between parietal and visceral) - Terminal portions of 25 papillary ducts - Receives fluid filtered through the capillary Renal lobe wall and the visceral layer - Renal pyramid and cortical tissue Filtration slits Renal lobule - Narrow gaps between interdigitating pedicels - Collecting tubules, papillary ducts, nephron RENAL FUNCTION Renal pelvis Filtration - Union of major calyces - Water and solutes in the blood leave the Renal pyramids (conical structure in the medulla) vascular space and enter the lumen of the - Straight collecting tubules and papillary ducts nephron - Portions of the loop of Henle and vasa recta Tubular reabsorption Area cribrosa - Substances move from the tubular lumen into - Area on renal papilla containing openings of the interstitium and capillaries the papillary ducts Tubular secretion Uriniferous tubule - Substances move from the epithelial cells of - Nephron + intrarenal ducts (collecting tubules tubules into the lumens and papillary ducts) - Usually after uptake from surrounding Medullary rays of ferrein interstitium and capillaries - Groups of parallel tubes at corticomedullary GLOMERULAR FILTRATION BARRIER junction (center of renal lobule) - Separates blood in the glomerulus from the - Collecting tubules: initial segment of bowman's capsule intrarenal ducts and loop of Henle Components: Interstitial tissue - Endothelium of glomerular capillaries, basal - GAGs, collagen fibers, capillaries, fibroblast, lamina, slit membrane, and subpodocyte mononuclear cells, and interstitial cells space Basal lamina 1. Aldosterone reabsorb sodium ions and little Lamina rara externa water Lamina dense 2. Secrete potassium and hydrogen Lamina rara interna COLLECTING TUBULES Glomerular filtration - Continuation of DCT - Blood passes through the capillaries - Simple cuboidal epithelium - Filtrate flows into renal tubules for - Carry filtrate into a collecting system that reabsorption and secretion transports it to a minor calyx - 20% of blood plasma is filtered - Increase reabsorption of water if needed - Initial filtrate similar to plasma except Intercalated cells it has little protein - Maintain acid-base balance PROXIMAL CONVOLUTED TUBULE - Present in the cortex - Longest segment confined in the cortex Arched collecting tubule - Simple cuboidal epithelium with microvilli - Cortex to medulla (brush border) on the luminal surface Straight collecting tubule - Striated basal infoldings of plasmalemma - Towards the medulla Functions: - Simple tall columnar epithelium 1. Reabsorb 70-80% water and sodium ions - Initial segment: component of medullary rays 2. Reabsorb glucose, AA, vitamins, and chloride PAPILLARY DUCT ions through facilitated transport - Duct of bellini formed by convergence of 3. Secrete creatinine and foreign substances straight collecting tubules LOOP OF HENLE JUXTAGLOMERULAR COMPLEX - Water retention by producing hypertonic urine - Located at the vascular pole Thin limb Atypical cell types: - Simple squamous epithelium 1. JG cells: tunica media of afferent arterioles - Confined to the medulla 2. Macula densa: distal convoluted tubules Thick descending limb 3. Extraglomerular mesangial cells: space - Freely permeable to water between macula densa and afferent arteriole - Cortex to medulla EXCRETORY PASSAGES Thick ascending limb Renal pelvis - Impermeable to water but permeable to Ureter sodium Urinary bladder - Medulla straight to the cortex Urethra - Ends by coming in contact with vascular pole MUCOSA of renal corpuscle of its parent nephron - Transitional epithelium except distal ⅔ of - Histologically identical with DCT urethra Short-looped nephrons (majority of nephrons) - Thin basement membrane - Cortical nephrons - Umbrella cells protect underlying cells - Renal corpuscles are in the outer portion of from cytotoxic effects of hypertonic the cortex urine - Thick, descending limb, short descending thin - Lamina propria limb, thick ascending limb - Thin in the pelvis and calyces Long-looped nephrons - Thick in the ureters and bladder - Juxtamedullary nephrons - LCT rich in elastic fibers - Renal corpuscles in the cortex are near the - Devoid of glands except near the juxtamedullary junction internal sphincter of the bladder - Loop of Henle goes deep into the medulla - Plenty of MALT DISTAL CONVOLUTED TUBULES No distinct submucosa - Entirety within the cortex MUSCULAR LAYER - Begins at vascular pole of renal corpuscle - Inner longitudinal and outer circular layer - Simple cuboidal epithelium with no microvilli - Thick in ureters and apical invagination - Well-developed three layers in the bladder Functions:  - Two longitudinal layers surrounding a thick - Muscular layer with circularly circular layer arranged smooth muscle cells ADVENTITIA - External urethral sphincter - Loose areolar connective tissue - Circularly arranged striated - Covers all passages except upper part of fibers urinary bladder (serous peritoneum) RESPIRATORY SYSTEM URETER - Supplies O2 and dispose off CO2 - Stellate lumen - Lungs and branching system of bronchial - Moves urine towards bladder via peristalsis tubes - Produce mucosal folds when empty Anatomical divisions URINARY BLADDER Upper respiratory tract - Storage of urine ○ Nasal cavity - Holds 400-600mL of urine in adults ○ Paranasal sinuses - Urge to urinate: 150-200mL ○ Nasopharynx - Ureters pass through walls obliquely Lower respiratory tract - Form valve to prevent backflow ○ Larynx - Highly vascularized lamina propria and DICT ○ Trachea of submucosa ○ Bronchial tree (arbor bronchialis) - Few to absent mucus secreting glands ○ Respiratory section - Mucosa forms irregular longitudinal folds Functional divisions - Detrusor muscle: 3 poorly delineated layers Conducting zone: cleans and humidifies air - Most distinct at the neck near the ○ Nose urethra ○ Pharynx - Contract to empty the bladder ○ Larynx URETHRA ○ Trachea - Carries urine from bladder to exterior ○ Bronchi - Mucosa: prominent longitudinal folds ○ Bronchioles (terminal bronchioles) MALE URETHRA Respiratory zone: site of gas exchange Prostatic urethra ○ Bronchioles (respiratory bronchioles) - Lined by urothelium ○ Alveoli - Glands of littre ○ Alveolar ducts - Branched tubuloalveolar ○ Alveolar sacs - Abundant elastic fibers and veins ○ Lungs - Poorly developed LCT PROCESSES OF RESPIRATION - Internal urethral sphincter Pulmonary ventilation Membranous urethra - Movement of air into and out of the lungs - Stratified columnar and pseudostratified External respiration columnar epithelium - Gas exchange between blood and alveoli - External urethral sphincter Internal respiration Spongy urethra (penile) - Respiratory gasses from lungs to tissue - Pseudostratified columnar epithelium RESPIRATORY EPITHELIUM - Nonkeratinized stratified squamous distally Ciliated columnar cells - Glands empty into lacunae of morgagni - Most abundant; move mucus - Erectile tissue Goblet cells - Receive ducts of bulbourethral glands of - Secrete mucus cowper Brush cells - Found in the sphincter urethra muscle - Columnar cell, chemosensory receptors FEMALE URETHRA Serous cells - Mucosa thrown into longitudinal folds - Columnar ciliated with dense apical granules - Transitional: initial; nonkeratinized stratified Basal cells squamous: continuous with labia minora - Short and rounded - Lamina propria with many mucus-secreting - Mitotically active stem and progenitor cells glands Granule cells (kulchitsky cell) Sustentacular cells - Part of diffuse neuroendocrine cells - Tall slender cells with long microvilli Clara cells - Ovoid nuclei above the center of the cell - Secrete surfactant - Contains lipofuscin granules - Found in trachea and bronchi Olfactory cells PLEURA - Spindle-shaped bipolar neurons - Fibrous tissue covering of the lungs - Dendrites terminate in the olfactory vesicle - Connective tissue lined by mesothelium with - Olfactory cilia abundant elastic fibers - Receptor elements radiating from the - Parietal and visceral layers continuous at olfactory vesicle hilum - Olfactory nerve fibers Parietal pleura (outer) - Forms olfactory nerves entering the - Consists of stomata cribriform plate to terminate in the Visceral pleura (inner) olfactory bulb - Elastic fibers continuous with those of the Basal cells pulmonary parenchyma - Branching cytoplasmic processes Pleural cavity - Dark, ovoid nucleus - Space between parietal and visceral - Stem cells that differentiate into sustentacular - Mesothelium produce serous fluid and olfactory cells - Lubricant during respiration PARANASAL SINUSES CONDUCTING ZONE (dead space) - Frontal, maxillary, ethmoidal, sphenoidal Nose bilateral cavities - Skin: sweat and sebaceous glands, vibrissae - Thinner respiratory epithelium with few goblet - Nasal mucosa epithelium cells - Respiratory epithelium - Lamina propria continuous with underlying - Junction of vestibule and rest of nasal cavity periosteum - Nonciliated cuboidal or columnar Functions - Lamina propria 1. Reduce bony mass of the face - Mucus and serous glands, mast cells 2. Resonating chambers for speech - Complex vasculature: capillary loops near 3. Air-conditioning of inspired air epithelial surface PHARYNX - Carries blood counter to inspired air - Lamina propria - Warms the air - Mucus glands: stratified squamous Seromucous glands epithelium - Secrete water for humidifying air - Mixed glands: respiratory epithelium - Traps particles and impurities that is rich in MALT - Secretions contain IgA (plasma cells of LP) - Submucosa: LCT Important structures - Lateral wall and terminal portion of External and internal nares nasopharynx Paranasal sinus - Muscularis externa Nasolacrimal duct - Inner longitudinal and outer circular Nasal cavity (internal) and vestibule (external) - Mostly skeletal muscles Nasal septum: separates two nasal cavities - Adventitia: LCT Conchae or turbinates Nasopharynx ○ 3 shelf-like projections from the lateral - Respiratory epithelium walls of the nasal cavity - Non-keratinized stratified squamous (roof) OLFACTORY EPITHELIUM Oropharynx - Pseudostratified ciliated columnar with no - Non-keratinized stratified squamous goblet cells and indistinct basal lamina Laryngopharynx - Thick lamina propria - Non-keratinized stratified squamous - Glands of bowman: serous fluid - LARYNX (voice box) solvent for odoriferous substances - Short passage of air between the pharynx and the trachea Unpaired cartilages Extrapulmonary bronchi - Thyroid cartilage, cricoid cartilage, epiglottis - Main bronchi before entering the lungs Paired cartilages Intrapulmonary bronchi - Arytenoids: hyaline - Mucous membrane thrown into folds - Cuneiform: elastic Smaller bronchi - Corniculate: elastic - Irregular plates of cartilage rings Folds - More prominent circular band of smooth - Upper fold: false vocal fold muscle that separates LP from submucosa - Pseudostratified columnar ciliated BRONCHIOLES (less than 1mm in diameter) epithelium - No cartilage, submucosal glands and - Lower fold: true vocal fold lymphoid nodules - Non-keratinized stratified squamous Mucosa - Vibrate and produce sound as air - Ciliated epithelium with very few goblets passes through the larynx from lungs - Transform from columnar to cuboidal distally Epiglottis - Clara cells - Flattened structure projecting from the upper - Cuboidal nonciliated with round apex rim of the larynx - Microvilli - Prevent entrance of food to the larynx - Dense secretory cytoplasmic granules - LP: mixed mucous and serous glands Lamina propria - Epithelial lining - Loose collection of MALT - Upper lingual surface: stratified - Distinct separation from submucosa squamous epithelium TERMINAL BRONCHIOLES (less than 0.5 cm) - Laryngeal surface: pseudostratified - Simple nonciliated cuboidal with no goblet columnar ciliated epithelium cells but many clara cells TRACHEA (windpipe) - Brush cells, DNES small granule cells - Hollow tube with tall respiratory epithelium Club cells or bronchiolar exocrine cells (clara) - C-shaped adult hyaline cartilage plates - Secrete surfactant - Maintains opening - Detoxification - Trachealis muscle - Secrete antimicrobial peptides and cytokines - Joins the free ends of cartilage rings RESPIRATORY ZONE Mucosa - Simple squamous distally - Thick basal lamina - Numerous clara cells - Numerous elastic fibers and MALT in the LP RESPIRATORY BRONCHIOLES (less than 0.5 cm) Submucosa: LCT - Formed by terminal bronchioles - Bronchial submucosal glands - Ciliated cuboidal with no goblet cells - Tubuloalveolar, mixed - Small number of clara cells Cartilage and muscular layer ALVEOLAR DUCTS - 16 to 20 c-shaped cartilages - Branching from respiratory bronchioles - Trachealis muscle: smooth muscle - Simple squamous epithelium Adventitia: present - Scanty CT elements with some smooth MAIN BRONCHI muscles on the walls - Bifurcation of the trachea which enter the - Knob-like structure on the wall for guarding lungs at the hilum entrance into the alveoli and alveolar sacs - Morphologically identical to the trachea ALVEOLI SECONDARY BRONCHI (lobar) - Arise from respiratory bronchioles and - Branching of the primary bronchi alveolar ducts - 2 in the right, 1 in the left lung - Wall: surface epithelium, supporting tissue, - Supply pulmonary lobes blood vessels TERTIARY (segmental) BRONCHI - Supporting tissue with reticular, collagenous, - Tall columnar with less pseudostratification, elastic fibers with occasional fibroblast goblet cells, and cartilage plates - Capillaries form extensive plexuses around - Bronchopulmonary segment: tertiary the alveoli bronchi + small branches it supplies Interalveolar septum Paracrine secretion - Wall of adjacent alveoli - Localized dispersal in interstitial fluid or - Simple squamous epithelium through short loops of the blood vessels - Connective tissue Juxtacrine secretion - Capillaries lined by endothelial cells - Signaling molecule remains on the secreting - Collagen, elastic, reticular fibers cell’s surface or adjacent extracellular matrix - Mast cells, plasma cells, lymphocytes, - Direct contact with other cells and interstitial fibroblasts Autocrine secretion Alveolar pores(pores of kohn) - Secretion acts on the cell itself or cells of the - Allow communication among adjacent walls same type - Alternate route of air if alveolus is blocked Endocrine secretion Type I pneumocytes - Cell target distant cell through bloodstream - 95% of the surface HYPOTHALAMUS (master gland) - Rest on a basal lamina - Below the thalamus above the pituitary gland Type II pneumocytes and brain stem - Larger than type I and appear between type I - Floor and part of the walls of the 3rd ventricle - Cuboidal or round with large round nucleus - Almond-sized structure that links endocrine to and prominent nucleolus with microvilli nervous system - Contains lamellar bodies Neurosecretory neurons - Secretory granules to produce - Secrete neurohormones surfactant - Releasing and inhibiting hormones Pulmonary macrophages (dust cells) that control secretion from anterior - Most numerous cells pituitary gland - Not part of the interalveolar septum Hypothalamic-hypophyseal portal veins BLOOD-AIR BARRIER - Carries neurohormones to the anterior - Separates blood in a pulmonary capillary pituitary gland from the air in the alveolus HORMONES PRODUCED: HYPOTHALAMUS - Binds hemoglobin in RBC Posterior pituitary hormones - O2 from alveoli to capillaries Oxytocin - CO2 from capillaries to alveoli Vasopressin - Most CO2 arrives as part of the Hypophysiotropic hormones H2CO3 inside RBC through carbonic Antidiuretic hormone (ADH) anhydrase Corticotropin releasing hormones (CRH) Components: Gonadotropin releasing hormone (GnRH) Capillary endothelial cell Growth hormone releasing hormone (GHRH) Pulmonary epithelial cell Growth hormone inhibiting hormone (GHIH) Basal lamina of alveolar epithelium Prolactin releasing hormone (PRH) Basal lamina of capillary endothelial cell Prolactin inhibiting hormone (PIH) LUNGS PITUITARY GLAND (Hypophysis cerebri) - Occupy entire thoracic cavity except the - Lies below the brain in the sella turcica mediastinum (cavity on the sphenoid bone) - Base, apex, hilum - Attached to the hypothalamus by the Blood supply infundibulum - Pulmonary arteries ANTERIOR PITUITARY - adenohypophysis - Deoxygenated blood to the lungs Pars distalis (75% of adenophysis) - Pulmonary veins - Fibrous capsule - Oxygen blood from the lungs to the - Winding cords of epithelial cell: secretory heart - Vascular sinusoids - Bronchial arteries - Connective tissue: reticular fibers - Blood supply of lung tissue Acidophils: cytoplasm stains red or orange ENDOCRINE SYSTEM - Polypeptide hormones - Secretions (hormones) reach target organs - Somatotrophs: GH (50% chromophils) through cell receptors via bloodstream - Lactotrophs: PRL Basophils: cytoplasm stains blue (larger than acid) ○ Target: opioid receptors - Glycoprotein hormones ○ Inhibit pain perception - Thyrotrophs: produce TSH POSTERIOR PITUITARY - neurohypophysis - Gonadotrophs: produce LH/FSH Pars nervosa (posterior lobe of pituitary) - Corticotrophs: produce ACTH - Neural tissue: unmyelinated axons of large Parenchymal cells secretory neurons - Chromophils and chromophobes (most are - Cell bodies in the supraoptic and actually chromophils paraventricular nuclei of the hypothalamus Types - Glial cells: pituicytes (resemble astrocytes) - Folliculostellate cells - Most abundant cell type - Undifferentiated stem cells - Abundant capillaries herring bodies Pars tuberalis - Less cellular with fibrous appearance - Tubular sheath from distalis and winds HERRING BODIES around pituitary stalk - Neurosecretory bodies - Components - Dilated areas of bulges in terminal portion of - Cords of epithelial cells axons containing neurosecretory granules - Hypophyseal portal vessels - Temporary storage of hormones (ADH and - Gonadotrophs and thyrotrophs oxytocin) Pars intermedia HORMONES STORED: NEUROHYPOPHYSIS - Boundary between anterior and posterior Antidiuretic hormone (ADH) and arginine - Separated from pars distalis via hypophyseal vasopressin (AVP) left ○ Target: kidney - Large pale cells surround follicle (Rathke’s ○ Reabsorption of water and elevation cyst) filled with colloid of blood volume and pressure - Produce melanocyte-stimulating hormone (vasoconstriction) HORMONES PRODUCED: ADENOHYPOPHYSIS Oxytocin Growth hormone ○ Target: uterus, mammary gland, ○ Secretory cell: somatotrophs ductus deferens, prostate gland ○ Target: liver and adipose tissue ○ Labor contraction and milk ejection ○ Growth and carbohydrate and lipid ○ Contraction of ductus def and prostate metabolism PINEAL GLAND (Epiphysis cerebri, conarium) Prolactin - Small and pine cone-shaped ○ Secretory cell: lactotroph - Base attached to posterior roof of 3rd ○ Target: mammary glands ventricle by two short stalks ○ Production of milk - Thin CT capsule from the pia mater Thyroid-stimulating hormone Pinealocytes ○ Secretory cell: thyrotrophs - Secretory cells with slightly basophilic ○ Target: thyroid gland cytoplasm and irregular euchromatin nuclei ○ Secrete thyroid hormones - Produce melatonin Luteinizing hormone Astrocytes ○ Secretory cell: gonadotrophs - Interstitial glial cells ○ Target: ovaries and testes - Found in perivascular areas and between ○ Regulate reproductive functioning groups of pinealocytes Follicle-stimulating hormone Mast cells ○ Secretory cell: gonadotrophs Brain sand/psammoma bodies/corpora arenacea ○ Target: ovaries and testes - Concretion of calcium and magnesium salts ○ Production of sex hormones from mineralized extracellular protein Adrenocorticotropic hormone deposit ○ Secretory cell: corticotrophs - Radiopaque ○ Target: adrenal gland (cortex) - Increases with age ○ Secretion of glucocorticoids Melatonin B-endorphin - Stimulated by darkness inhibited by light ○ Secretory cell: corticotrope - Regulate sexual maturity (delays puberty) - Regulate circadian rhythm THYROID GLAND (largest endocrine gland) ADRENAL GLAND (suprarenal gland) - Anterior and inferior to the larynx - Paired organs on the superior poles of kidney - Two lobes united by isthmus - Encapsulated and embedded in the pararenal - Fibrous capsule divided into ill-defined lobule adipose tissue and fascia Thyroid follicles - Parenchyma with secretory epithelial cells - Colloid cells secreting thyroxine (T4) and ADRENAL CORTEX (outer) triiodothyronine (T3) - Immediately beneath the capsule - Lined by follicular cells with regularly Zona glomerulosa (15%) arranged dark spherical nuclei - Immediately inside the capsule - Simple cuboidal epithelium - Cells in clusters separated by trabeculae - Central lumen with gelatinous acidophilic - Secretes mineralocorticoids colloid - Regulate fluid and electrolyte balance Follicular cells (principal cells) - Aldosterone - Epithelial cells with microvilli - Major regulator of salt balance - Produce thyroglobulin which combines iodine - Stimulated by angiotensin II to produce T3 and T4 Zona fasciculata (65-80%) Parafollicular cells - Arranged in columns - Cytoplasm with secretory granules - Long cords of large polyhedral cells filled with - Secrete calcitonin lipid droplets separated by sinusoidal THYROID HORMONES capillaries T3 and T4 - Secretes glucocorticoids - Increase basal metabolic rate - Cortisol: principal hormone - Help maintain normal body temperature - Gluconeogenesis and glycogen - Increase glucose, fat, and protein metabolism synthesis Thyrocalcitonin - Regulate body metabolism and stress - Regulate calcium homeostasis resistance - Decreases blood calcium levels - Anti-inflammatory PARATHYROID GLAND - Suppress immune functions - Two pairs of ovoid yellowish bodies (0.4g) - Fat mobilization and muscle - Posterior of the lateral lobes of thyroid gland proteolysis - Embedded in the thyroid capsule Zona reticularis (innermost: 10%) - CT capsule; divided into ill-defined lobules - Smaller cells with fewer lipid droplets - Stroma formed by CT with reticular - Secretes androgens fibers (dehydroepiandrosterone and - May contain follicles androstenedione) Parenchyma - Libido in females - Epithelial cells in cords and clusters - Converted to estrogen to stimulate - Parenchyma cells (chief and oxyphil) secondary sex characteristics - Parathyroid hormone ADRENAL MEDULLA Chief cells (principal cells) - Large, pale-staining polyhedral cells arranged - Most numerous in cords or clumps supported by reticular fiber - Produce parathyroid hormones - Medullary veins: central area Oxyphil cells (acidophil cells) - Parenchymal cells: phaeochromocytes or - Absent in children chromaffin cells - Bigger than chief but smaller nucleus - Produce catecholamines - Degenerated derivatives of principal cell Phaeochromocytes or chromaffin cells - Abnormally shaped mitochondria - Electron dense granules for storage and PARATHYROID HORMONE secretion of catecholamines - Increases blood calcium levels - Norepinephrine-secreting cells with bigger - Target structures and more electron dense granules - Osteoblast - Epinephrine secreting cells - Distal convoluted tubules - Small intestines CATECHOLAMINES Pancreatic polypeptide PP cells (F cells) - Enhance effects of sympathetic NVS - Rare - Stimulate glycogen breakdown elevating - Widely scattered blood glucose levels - Irregularly shaped secretory granules Epinephrine - Produce pancreatic polypeptide - Increase heart rate, dilate bronchioles and DIGESTIVE SYSTEM arteries of cardiac and skeletal muscle Digestive tract - 80% of catecholamine secreted Oral cavity Norepinephrine Esophagus - Constrict vessels of digestive and skin Stomach - Increase blood flow to the heart, muscle, and Small and large intestine brain Anus Chromaffin cells Associated glands - Where conversion of norepinephrine to Salivary glands epinephrine occurs Liver ADRENAL MEDULLA HORMONES Pancreas Heart Functions - Increase rate and force of contraction 1. Ingestion Blood vessels 2. Mastication (chewing) - EP: Dilate vessels in skeletal muscles 3. Motility decreasing resistance to blood flow 4. Secretion of lubricating and protective mucus, - NP: Increase blood flow to skeletal muscles digestive enzymes, alkaline and acidic fluids, with constriction of vessels in skin and and bile viscera 5. Hormone release for local control of motility Systemic blood pressure and secretion - EP: Increases due to increased cardiac 6. Chemical digestion output 7. Absorption of small molecules and water into - NP: increase greatly due to vasoconstriction the blood and lymph Airways 8. Elimination of indigestible and unabsorbed - EP: dilates components of food - NP: dilates slightly TUNICA MUCOSA Reticular formation of brain - Stratified squamous: mouth, esophagus, - EP: activates anus - NP: produces little effect - Simple columnar: other parts PANCREAS - Lamina propria - Islets of langerhans: pale staining cells in the - Muscularis mucosa acinar exocrine tissue of the pancreas - Inner circular outer longitudinal - Mostly in the tail region smooth muscle - Very thin reticular capsule TUNICA SUBMUCOSA Alpha cells - CT: blood and lymph vessels, nerve fibers - Large cells in the peripheral area - Plenty of GALT - Secretory granules of uniform size Submucosal plexus of meissner - Secrete glucagon - Autonomic neurons and nerve fibers Beta cells - Controls digestive secretions and reacts to - Smallest but most numerous presence of food - Occupy central area - Esophagus, stomach, and intestines - Smaller and less electron dense granules TUNICA MUSCULARIS (muscularis externa) - Secrete insulin - Smooth muscle cells arranged in sublayers Delta cells Myenteric plexus of auerbach - Largest - Autonomic neurons and nerve fibers - Scattered singly all over the islets - Digestive motility - Granules similar to a but less electron dense Interstitial cells of cajal (pacemakers GI motility) - Produce somatostatin - Histologically similar to smooth muscles TUNICA SEROSA (visceral peritoneum) - Supportive, immature, and slowly dividing - Thin sheet of LCT rich in blood vessels, basal stem cells lymphatics, and adipose tissue - Base rests on a basal lamina and entered by - Simple squamous epithelium or mesothelium afferent sensory axons which synapse with - Adventitia not covered by mesothelium gustatory cells MOUTH/ORAL CAVITY Taste pore - Vestibules and oral cavity proper - Where molecules dissolved in saliva contact - Non-keratinized stratified squamous on microvilli to interact with taste receptors internal surfaces Five categories of tastants - Lips, cheeks, soft palate, tongue 1. Salty: sodium - Keratinized stratified squamous 2. Sour: hydrogen ions from acids - Outer lips, hard palate, and gums 3. Sweets: sugars - Lamina propria: LCT with blood, lymph 4. Bitter: alkaloids and toxins vessels, nerves, and GALT 5. Umami: glutamate and aspartate - No muscularis mucosa PHARYNX Surface of the lips (vermillion zone) - Nasopharynx, laryngopharynx, oropharynx - Inner surface: many minor labial salivary ESOPHAGUS glands - Muscular tube; 25 cm long in adults - Very thin keratinized stratified squamous - Transports from pharynx to stomach - Transitional between oral mucosa and skin Mucosa: - No saliva or sweat glands - Non-keratinized stratified squamous - Outer surface with hair follicles and - Langerhans cells at basal area of epithelium sweat glands Lamina propria: - Sensory innervation and capillaries which - rich in GALT impart pink color - Esophageal cardiac glands Hard palate and gums - Simple tubular gland at the level of - No submucosa in the gingiva and midline of cricoid cartilage and lower end of the hard palate esophagus - Palatine glands where submucosa is present Submucosa: Muscularis externa (skeletal muscle) - CT with GALT, elastic fibers, blood vessels - Lips and cheeks - Esophageal glands proper Subcutaneous tissue (adventitia) - Compound tubulo-alveolar that - External to muscularis externa of the lips and secrete mucus cheeks Muscularis externa: inner circular, outer longitudinal TONGUE - Skeletal fibers: upper ⅓ - Mass of striated muscle covered by mucosa - Mixed skeletal and smooth fibers: middle ⅓ - Muscle fibers in all directions to allow high - Smooth muscle: lower ⅓ level of mobility for food mastication Adventitia: outermost layer - Lamina propria makes mucous membrane Serosa: outer layer of the part inside the abdomen adhere to muscular core Gastro-esophageal junction Lingual papillae - Simple columnar epithelium 1. Filiform: numerous, elongated, cone-shaped STOMACH - Heavily keratinized - Continues digestion of carbohydrates - Rough surface for movement of food - Physically breaks down food 2. Fungiform: less numerous, mushroom-shape - Cardia, fundus, body, pylorus - Lightly keratinized Chyme 3. Folate: rudimentary in humans - Mixing of acid and ingested to ingested food 4. Vallate: largest papillae by churning of the muscularis - In front of sulcus terminalis Lipase - Most number of taste buds - Begins digestion of triglycerides Taste buds Pepsin - Ovoid structures on the surface - Promotes initial digestion of proteins - Sample general chemical composition of food Cardia and pylorus - 50-100; half of which are gustatory cells - Mucus production Body and fundus G-cells: secrete gastrin - Site of gastric glands releasing acidic juice EC-cells: secrete serotonin Mucosa and submucosa of empty stomach D-cells: secrete somatostatin - Rugae (folds) flattens when stomach is full Enterochromaffin-like cells: histamine Mucosa: CARDIAC GLANDS - Simple columnar with surface mucous cells - Least numerous and invaginates into the LP - Mucus glands with mucous-secreting cells - Gastric foveolae/pits - Some enteroendocrine, zymogenic, and - Secrete viscous mucous layer parietal cells - Lead to long, branched, tubular gland PYLORIC GLANDS Lamina propria: - Shorter but more coiled - LCT with few elastic fibers, smooth muscle - Most are mucous-secreting cells and cells, and GALT enteroendocrine cells Muscularis mucosa: - With stem cells and some parietal cells - Well-defined with secretory cells - No zymogenic cells - Inner circular; outer longitudinal SMALL INTESTINES - Contracts to empty glands - Complete digestion and absorption Submucosa: Modifications in the mucosa and submucosa - Thick CT with blood vessels, nerves, GALT 1. Horizontal mucosal folds Muscularis externa: - Plicae circulares, valves of Kerckring, - Inner oblique, middle circular, outer valvulate conniventes longitudinal fibers - Most developed in the jejunum and - Myenteric plexus of auerbach between absent in the first part of duodenum circular and longitudinal fibers and distal half of the ileum Serosa: outermost 2. Intestinal villi STOMACH GLANDS - Finger-like projections of the mucosa - Confined to the mucosa - Simple columnar with enterocytes - Simple tubular or simple branched tubular surrounded by goblet cells - Open into the bottom of gastric pits 3. Microvilli: brush or striated border Isthmus: part opening into the gastric pit Mucosa (simple columnar) Neck: immediately basal to the isthmus - Enterocytes: most numerous tall columnar Base: below the neck cells FUNDIC GLANDS: longest and most numerous - Absorptive epithelium and secretory in - Parietal or oxyntic cells the crypts - Most easily identifiable - Goblet cells: interspersed on absorptive cells - Produce HCl and intrinsic factor - Enteroendocrine cells: entire epithelium Intrinsic factor: needed to absorb vitamin B12 in the - M-cells (microfold cells) terminal region of the ileum - Areas with great amounts of GALT - Chief or zymogenic cells (ileum) - Most numerous in the fundic glands - Transepithelial transport of particles - Secretory granules with pepsinogen - Mucosa of ileum overlying lymphoid - Basal portion of fundic glands follicles of peyer’s patches - Mucous neck cells - Intraepithelial lymphocytes - Secretory granules with mucin - T cells for local immunity - Protect stomach surface CRYPTS OF LIEBERKUHN - Stem cells - Simple tubular glands - Upper part of fundic glands - Invaginations of epithelium into the LP - Differentiate into mucous and gastric - Enterocytes gland cells - Absorptive epithelium and secretory in - Renew epithelial cells of the stomach the crypts - Enteroendocrine cells - Goblet cells - Enterochromaffin, argentaffin, - Secrete glycoprotein mucins hydrated hormone-producing cells to form mucous (upper part of gland)  - Paneth cells - Penetrated throughout its length by tubular - Secrete lysozyme, phospholipase A2 intestinal glands and defensins - Lined by goblet and absorptive cells - Capable of phagocytosis and small number of enteroendocrine - Basal parts of the gland - Columnar absorptive cells (colonocytes) with - Stem cells irregular microvilli and dilated intercellular - Most numerous and occupy middle spaces region of the glands - Transverse musical folds in the rectum - Short columnar cells that regenerates - Stratified squamous epithelium at the rectum the surface and glandular epithelia and becomes keratinized at the anal verge - Enteroendocrine cells Lamina propria: - Gastric, somatostatin, serotonin, - Rich in GALT and contains more lymph enteroglucagon, cholecystokinin, nodules extending to the submucosa gastric inhibitory protein, motilin, CRYPTS OF LIEBERKUHN neurotensin, PP, secretin - Longer than those in the small intestines Lamina propria Submucosa: - LCT with plenty of blood and lymph vessels, - Thick and richly supplied with GALT nerves, and GALT - Devoid of glands - Smooth muscle fibers, lymphocytes, mast Muscularis externa: cells, plasma cells, macrophages - Forms the taenia coli Muscularis mucosa: outermost layer of mucosa - 3 narrow longitudinal bands of smooth Submucosa: muscles - Larger blood and lymph vessels and the - Absent in the rectum diffuse, interconnected neurons of the Serosa: submucosal meissner nerve plexus - Outermost with appendices epiploicae - Peyer’s patches: aggregates of lymph nodes - Adipose that form pendolous masses - M-cells (membranous or microfold cells) VERMIFORM APPENDIX GLANDS OF BRUNNER - Tubular evagination of the cecum - Compound coiled tubular glands of the - Simple columnar with microvilli, few goblet, duodenum enteroendocrine, and short crypts of - Secrete alkaline mucus which neutralize lieberkuhn which may have paneth cells chyme entering the duodenum Submucosa: - Secrete epidermal growth factor - Thick and heavily infiltrated by GALT (urogastrone) Muscularis externa: complete, not well developed Muscularis externa: Serosa: outermost covering - Inner circular, outer longitudinal fibers ACCESSORY GLANDS - Thicker in the proximal than distal portion Minor salivary glands MYENTERIC AUERBACH PLEXUS - Lamina propria of the oral cavity - Located in between layers of muscle fibers Major salivary glands (compound tubuloalveolar) Serosa: most external histologic layer - Primarily exocrine glands Adventitia - Secretions empty into the oral cavity - Most external layer of the 2nd and 3rd portion - Secrete only in response to appropriate of the duodenum (no peritoneum) stimuli LARGE INTESTINE - Secrete epidermal growth factor - Propel fecal matter towards the anus Parenchyma: - Absorb remaining water and electrolytes - Glandular epithelium (simple cuboidal) - Provide vitamin K - Secretory units: acini, secretory - Devoid of valves of kerckring and villi tubules - Cecum, appendix, ascending colon, - Stroma: supporting structure transverse colon, descending colon, sigmoid - Passage for ducts, blood, and lymph colon, rectum, anal canal vessels and nerves Mucosa: - Capsule and septate divide gland into - Contain crypts of lieberkuhn lobes and lobules Duct system Stroma: connective tissue Intralobular duct: within lobules - Glisson’s capsule - Myoepithelial cells - Collagen and elastic fibers - Intercalated ducts surrounding lobes of the liver - Directly drains an acinus or tubule - Mesothelium: lines the capsule except - Simple squamous or low cuboidal that on the inferior surface of the - Striated duct diaphragm - Union of intercalated ducts - Hepatic lobules - Simple cuboidal or columnar - Formed by connective tissue septae Excretory ducts - Reticular fibers - Interlobular ducts Hepatocytes - Union of striated ducts - Polygonal cells arranged in layers with 1 or 2 - Stratified cuboidal to columnar microvilli - Lobar ducts Parenchyma: - Union of interlobular ducts - 80% cell population: hepatocytes - Stratified columnar - Divided into hepatic lobules - Main excretory ducts Hepatic lobules - Open into the oral cavity - Hepatic plates/cords - Stratified to pseudostratified columnar - Layers of hepatocytes arranged - Nonkeratinized stratified squamous around a central vein - Near opening into oral cavity - Hepatic sinusoids PAROTID GLANDS - Sinusoidal capillaries in between - Largest salivary gland below and anterior to hepatic plates the pinna of either ear at the angle of the - Receive venous and arterial blood mandible - Drain into central vein - Purely serous gland - Thin endothelium with endothelial and - Apical portion of serous cells with von kupffer cells eosinophilic zymogen granules VON KUPFFER CELLS - Connective tissue septae - Stellate cells with cytoplasmic processes - Main secretory duct: stensen’s duct - Fixed macrophages which phagocytose - Opens into vestibule opposite the 2nd bacteria and particulate matter upper molar tooth - Remove worn out RBC from circulation and SUBMANDIBULAR GLANDS recycle their iron content - Thinner connective tissue capsule Extrahepatic biles passages - Less adipose tissue Hepatic ducts - Mixed gland Common hepatic duct - Wharton’s duct Cystic duct - Opens into oral cavity underneath the Common bile duct tongue Mucosa: SUBLINGUAL GLAND - Simple columnar epithelium - Almond-shaped glands under the tongue - Lamina propria with simple tubuloalveolar - Lacks a definite capsule mucus glands - Mixed gland - Muscularis and serosa/adventitia - Ducts of Rivinus GALLBLADDER - Smaller ducts - Pear-shaped hollow pouch in the gallbladder - Ducts of Bartholin fossa on the right edge of the visceral surface LIVER (largest internal organ) of the liver - Adults: 1.5 to 2% of body weight - Concentrates, acidifies, and temporarily - Right upper quadrant of abdomen below the stores bile diaphragm Mucosa: - Exocrine gland: secretes bile - Simple tall columnar epithelium - Endocrine gland: produce hormones like Lamina propria: LCT thrombopoietin and erythropoietin - No true glands; simple tubuloalveolar (neck) ROKITANSKY-ASCHOFF SINUSES FEMALE REPRODUCTIVE SYSTEM - Epithelial invaginations into the LP and Internal genitalia muscle layer (diverticuli) - Ovaries Muscularis: - Uterus - Smooth muscles longitudinally, circular, and - Fallopian tube oblique - Vagina - Cholecystokinin External genitalia (vulva) - Induce smooth muscle contraction to - Clitoris relax sphincter of oddi allowing bile to - Labia minora and majora enter the duodenum - Glands that open into vestibules - Produced by enteroendocrine cells of Functions small intestines 1. Production of the female gamete (oocyte) Serosa: 2. Provision of environment for fertilization of - Posterior and inferior surfaces of gallbladder ova by spermatozoa Adventitia: adjacent to liver 3. Reception of male gametes PANCREAS 4. Provision of an environment for the - Stretches transversely across the posterior development of the embryo through the fetal abdominal wall from duodenum to spleen stage up to birth - Posterior to the stomach 5. Provision of passageway of the fetus during - Both endocrine and exocrine birth Stroma: 6. Production of sex hormones - Thin indistinct capsule CLITORIS - Lobules separated by CT septae - Homologous to penis - Secretory units: islets of langerhans - Two cavernous bodies made up of erectile and acini tissue which end distally as the glans clitoridis - Intralobular ducts (exocrine pancreas) - Corpora cavernous Islets of langerhans - Stratified squamous epithelium - Endocrine portion LABIA MINORA - Small aggregates of pale-staining cells - Form lateral walls of the vestibule dispersed among exocrine acini and ducts - Stratified squamous epithelium with no hair with dark-staining cells - Highly vascularized connective tissue with Pancreatic acini numerous sebaceous glands - Bulk of pancreatic lobules LABIA MAJORA - Grape-like clusters of epithelial cells - Homologous to scrotum - Simple columnar to pyramidal cells - Covers minora and highly pigmented - RER: synthesize enzymatic components of MINOR VESTIBULAR GLANDS pancreatic juice - Mucus secreting gland located at the urethral Ducts opening - Intercalated ducts, intralobular ducts, - Resemble glands of littre in males interlobular ducts, duct of Wirsung, duct of MAJOR VESTIBULAR GLANDS Santorini - Pair of larger glands in the wall of the Intercalated ducts vestibule - Simple squamous or low cuboidal - Branched tubuloalveolar and mucus secreting - Receive secretions from the acini and drain that resemble bulbourethral glands in male into intra and interlobular ducts OVARY - Centroacinar cells - Almond-shaped, 3 cm long, 1.5 cm wide, 1 - Epithelial cells telescoped into the cm thick acinus - Site of oogenesis and hormone production Ducts of wirsung - Germinal epithelium: simple cuboidal or - Simple columnar main excretory duct simple squamous Duct of santorini - Tunica albuginea - Simple columnar accessory excretory duct - DICT capsule beneath the epithelium that continues to the duodenum Cortex Hepatopancreatic ampulla (ampulla of vater) - Thick periphery made up of highly cellular CT - Duct of wirsung + common bile duct with numerous ovarian follicles Medulla - Passageway for ovum towards the uterus and - Vascular inner zone made up of LCT for sperm on their way to fertilize the ovum - Blood vessels enter the hilum from Regions: mesenteries suspending the ovary 1. Infundibulum: funnel-shaped with fimbriae OVARIAN FOLLICLES 2. Ampulla: longest where fertilization occurs - Contain developing oocyte surrounded by 3. Isthmus: narrow with less mucosal folds cells and tissues 4. Intramural: passes through the wall of uterus Primordial ovarian follicles Mucosa - Primary oocyte surrounded by a single layer - Numerous folds in the ampulla of flattened follicular cells, granulosa cells, - Simple columnar epithelium and basal lamina - Ciliated: infundibulum and ampulla - Large nucleus at first meiotic phase - PEG cells: nonciliated secretory cells - Located at the superficial ovarian cortex Lamina propria Primary follicles - Very cellular LCT richly supplied with blood - Unilaminar primary follicle and lymph vessels - Granulosa (follicular) cells with - No glands cuboidal shape Muscularis - Multilaminar primary follicle - Inner circular outer longitudinal - Stratified follicular epithelium Serosa (granulosa) due to repeated mitosis - Plexus of nerves - Zona pellucida - Richly supplied with blood and lymph vessels - Thick homogenous layer of UTERUS glycoprotein and acid proteoglycans - Pear-shaped dorsoventrally flattened hollow between oocyte and follicular cell pelvic organ - Zona granulosa - Receives and nurtures embryo - Several layers of granulosa cells Parts: - Theca folliculi: envelops the follicle 1. Body: largest - Theca interna: cellular and vascular 2. Fundus: area between two oviducts - Theca externa: fibrous 3. Isthmus: narrowest Secondary follicle (antral follicle) PERIMETRIUM (adventitia or serosa) - Stratified epithelium made up of granulosa - Outer connective tissue layer cells MYOMETRIUM - Cumulus oophorous - Thickest layer made up of bundles of large - Thickening of granulosa cells with and long smooth muscle fibers oocyte in the middle - Increase in size with estrogen and are - Antrum: fluid-filled cavity smallest after menstruation Graafian follicle (matured secondary follicle) - Hyperplasia during pregnancy - Final stage of follicular development ENDOMETRIUM - Thinner cumulus oophorous with larger - Site of implantation and development of antrum embryo - Oocyte surrounded by corona radiata - Simple columnar epithelium with endometrial - Ruptures during ovulation releasing ovum glands which are simple tubular glands with zona pellucida and corona radiata - Lamina propria: fibroblasts, lymphocytes, and Corpus luteum leukocytes - Formed after ovulation Functional layer - Granulosa lutein cells: progesterone - Superficial thick layer that sheds - Theca lutein cells: progesterone and - Spongy LP rich in ground substance precursors of testosterone and estrogen - Includes most of the length of the glands Corpus albicans Basal layer - Scar tissue produced by degenerated corpus - Deeper layer which regenerates epithelium luteum due to lack of fertilization after menstruation - Loaded with lipids - Contains deep basal ends of glands UTERINE TUBES (oviducts, fallopian tube) - Basal glycogen deposits at the - Muscular tube 12 cm long epithelial cells (pale-staining) CERVIX - Higher rate of epithelial desquamation during - Inferior portion of the uterus projected into the progestational phase than estrogenic phase vaginal vault MAMMARY GLANDS - Forms part of birth canal during pregnancy - Modified sweat glands with subcutaneous - Prevent entry of microorganisms into the fatty tissue uterus - 15-20 lobes separated by interlobar CT - Secretions of glands to lubricate vaginal - Cooper's ligament: support breasts canal to facilitate passage of spermatozoa Lobules: secretory alveoli and tubules Parts: Intralobular ducts 1. Cervical canal: lumen - Drain secretory alveoli and tubules 2. Internal os: opens to the main uterine lumen - Unite to form interlobular ducts 3. External os: opens to the vagina Interlobular ducts Mucosa - Form lactiferous duct which opens into the - Plicae palmatae: folds nipple - Simple columnar: cervical canal Lactiferous sinus - Nonkeratinized stratified squamous: portio - Dilated terminal portion of lactiferous duct vaginalis which stores milk - Cervical glands Nipple - Extensively branching - Skin protrusion of the mammary glands mucus-secreting tubular glands - Highly pigmented with many nerve endings - Lamina propria: plenty of lymphoid elements - Exit point of milk orifices of lactiferous duct Endocervical mucosa Areola - Simple columnar near the cervical canal - Hair follicle, sweat, sebaceous glands - Thick lamina propria with plenty of glands - Glands of montgomery (apocrine glands) - Lack spiral arteries FEMALE REPRODUCTIVE CYCLE - Does not change thickness during ovarian 1. Ovarian cycle cycle and is not shed in menstruation 2. Uterine menstruation cycle Exocervical mucosa OOGENESIS - Nonkeratinized stratified squamous - Initial stage: differentiation of oogonia into - Where cervical carcinomas arise bigger cells called primary oocytes Transformation zone - Meiosis I: primary oocyte produces 2 haploid - Junction between squamous and daughter cells mucus-secreting columnar epithelium - Meiosis II: completed upon fertilization Cervical mucus: influenced by progesterone MENSTRUAL PHASE CERVICAL EFFACEMENT - First 5 days of endometrial cycle - Remodelling and collagen removal of CT of - Due to reduction of progesterone and the cervix before parturition estrogen - Soften the cervix and dilate cervical canal - Small secondary follicles in the ovary enlarge VAGINA - Uterine spiral arteries constrict leading to - Fibromuscular tube that extends from the ischemia of functional layer vestibule to the cervix PREOVULATORY PHASE - Organ copulation and passageway of fetus - Proliferative Mucosa - Secondary follicles in one ovary becomes the - Rugae: transverso folds dominant follicle - Non-keratinized stratified squamous - FSH decreases - Lamina propria - Estrogen stimulates endometrium repair - Vascular DCT with elastic fibers and OVULATION MALT - Release of secondary oocytes - No glands and submucosa POST-OVULATORY PHASE Muscularis - Secretory phase - Inner circular outer longitudinal - LH secretion stimulates production of corpus Adventitia luteum for secretion - DCT with nerve bundles and venous - Corpus luteum persist after fertilization plexuses - Corpus albicans produced without fertilization - Hormones cause thickening of endometrium MALE REPRODUCTIVE SYSTEM - Contains seminiferous tubules and CT stroma - Produce and transport male gametes Seminiferous tubules - Produce male sex hormone - 1-4 tubules each lobule External genitalia: SCROTUM - Highly coiled tubes filled with fluid - Testes, epididymis, part of the vas deferens - Germinal or spermatogenic epithelium - Dartos and cremaster muscles - Sertoli cells PENIS - Dividing cells of the spermatogenic - Male copulatory organ lineage - Three cylindrical masses bound by CT Outer fibrous sheath covered by external skin - Myeloid cells which are contractile cells Cavernous bodies propelling sperm into the duct system - Two located dorsally - Inner stratified epithelium with gametes and - Erectile tissue sertoli cells - Labyrinthine system of anastomosing Tall columnar epithelial cells blood channels that fill with blood - Nourish spermatogenic cells and divide Corpus spongiosum seminiferous tubules into basal and adluminal - Expands to form glans penis Interstitial tissue - Ventral and surrounds penile urethra - Between seminiferous tubules Penile urethra - Interstitial cells of leydig - Pseudostratified columnar to stratified - Produce testosterone squamous in the glans - Develop during puberty - Urethral glands secreting mucus - Contains crystals of reinke Root PROCESSES OCCURING IN THE TESTES 1. Bulb: bulbospongiosus muscle for ejection 1. Spermatogenesis: spermatogonia to 2. Crura: ischiocavernosus muscle for erection spermatozoa Tunica albuginea 2. Spermatocytogenesis: meiosis - Binds and encapsulate three cavernous 3. Spermiogenesis bodies INTRATESTICULAR GENITAL DUCTS - Dense regular collagenous CT Tubuli recti Glands of tyson - Immediate continuation of semi tubules - Sebaceous glands with no hair follicles - Located in the mediastinum testes - Undersurface of the prepuce and proximal - Epithelium portion of the glans penis - Initial: sertoli cells with no gametes - Forms the smegma - Distal: columnar or cuboidal with Hypodermis microvilli - LCT external to tunica albuginea - Supported by DICT externally - Plenty of blood vessels, few smooth muscle Rete testis cells, and no fat cells - Network of anastomosing canals with Skin irregular lumens within the mediastinum testis - No hair follicles - Where tubuli recti empty - Limited amount of sweat glands - Canal lined by a single layer of cuboidal or Internal genitalia: TESTES squamous cells - Pair of oval bodies in the scrotum Ductuli efferentes - Produce sperm and male sex hormones - 12-20 fine tubules penetrating the albuginea Tunica vaginalis - Epithelium - Portion of the peritoneum covering the testes - Scalloped appearance Tunica albuginea - Columnar ciliated - DICT fibrous capsule surrounding the testes - Cuboidal nonciliated with microvilli - Mediastinum testis - Exit testis at its posterosuperior surface - Thickening of tunica albuginea at the - Forms ductus epididymis posterior surface - Circularly arranged smooth muscle cells - Entry and exit of vessels and ductuli external to the epithelium efferentes EXTRATESTICULAR GENITAL DUCTS Testicular lobules Epididymis - Formed by connective tissue septa - Sperm maturation  - C-shaped on the posterior and superior Mucosa surface of the testis - Folds projecting into the lumen - Mucosa, muscularis, adventitia - Simple columnar epithelium Head - No muscular layer - Associated with superior pole - Surrounded by fibromuscular tissue of - Distal portion of ductuli efferentes and highly prostate gland coiled ductus epididymis URETHRA - Body and tail - Passage of urine and semen Ductus epididymis - Prostatic urethra: widest and most dilatable - Absorption of excess fluid in semi tubules - Membranous and spongy urethra - Pseudostratified epithelium surrounded ACCESSORY SEX GLANDS externally by smooth muscle SEMINAL VESICLE Principal cells - Secretions added to seminal fluid - Absorb 90% of the fluid - Fructose, fibrinogen, prostaglandin - Tall columnar proximally to cuboidal distally - Long highly coiled narrow tubes enveloped by - Apical surface with stereocilia vascular CT capsule Basal cells Mucosa - Small rounded or pyramidal resting on basal - Maze appearance due to branched folds lamina between bases of principal cells - Nonciliated pseudostratified columnar or Smooth muscle cells cuboidal epithelium - Initial: circular - Cells contain lipochrome pigments - Distal: inner and outer longitudinal, middle Muscularis circular - Inner circular outer longitudinal DUCTUS DEFERENS Adventitia - Fibromuscular tube that starts at the most - CT with elastic elements inferior portion of the tail of the epididymis PROSTATE GLAND - Embedded in the spermatic cord - Largest accessory gland surrounding urethra - Ductus deferens with arteries and below the bladder veins - 30-50 tubuloacinar glands (stroma) - Testicular artery and pampiniform - Simple or pseudostratified columnar plexus of veins - Contraction of smooth muscle during - Lymph vessels and nerves of testes ejaculation Three layers of DCT Three major zones of glands in the parenchyma 1. Internal spermatic fascia 1. Transition zone: periurethral mucosal glands 2. Cremasteric fascia: longitudinal skeletal which are the last numerous glands muscles 2. Central zone: submucosal glands with longer 3. External spermatic fascia duct SPERMATIC CORD LAYERS 3. Peripheral zone: main prostatic gland Ampulla - 70% of glands - Distal segment of vas deferens Stroma - More numerous and complex mucosal folds - DCT with plenty of smooth muscle fibers - Simple columnar epithelium - Envelops the gland DUCTUS DEFERENS HISTOLOGIC LAYERS - Septae divide gland into lobules Mucosa Parenchyma: compound tubuloalveolar - Longitudinal folds causing irregular shape to 1. Main prostatic gland: most numerous narrow lumen - Peripheral 1/3 - Pseudostratified columnar with stereocilia 2. Submucosal gland Muscularis - Inner 1/3 - Thick inner and outer longitudinal and middle 3. Mucosal gland: least numerous circular - Immediately surrounds prostatic Adventitia urethra - CT with blood and lymph vessels and nerves Functions that supply the duct - Secrete citric acid, acid phosphatase, and EJACULATORY DUCT proteolytic enzymes - Ductus deferens + duct of the seminal vesicle Alveoli - Simple columnar, squamous, cuboidal or pseudostratified Lamellated concretions - Prostatic concretions (corpora amylacea) - Glycoproteins deposited around cell fragments BULBOURETHRAL GLAND - Compound tubuloalveolar mucus gland Thin CT capsule - Collagen and elastic fibers - Smooth and striated muscle cells - Septa divide glands into lobules Alveoli - Simple cuboidal with nucleus towards the base of the cell Ducts - Simple tall cuboidal or columnar Main excretory duct - Pseudostratified columnar Function - Secrete alkaline fluid or mucus for lubrication SEMEN - Sperm + seminal fluid - 50-150 million sperms per mL Head - Nucleus and acrosome - Hydrolytic enzymes that disperse cells of corona radiata and digest zona pellucida Tail - Identical to cilia with flagellum - Neck: connecting piece - Middle piece: mitochondrial sheath - Principal piece: enclosed by fibrous sheath - End piece: not enclosed by fibrous sheat