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| Hormone | Produced by endocrine cells; Chemical messenger produced by 1 cell type which affects function of another cell (target cell); Target cells must have receptor specific for hormone; Secreted directly into blood or lymph |
| Endocrine Tissues | Frequently works in associate with NS; Isolated cells-enteroendocrine cells; Mass of endocrine cells embedded in exocrine glands-islets of Langerhans; Endocrine organs |
| Pituitary Gland | Hypophysis-Adenohypophysis (anterior) and Neurohypophysis (Posterior) |
| Adenohypophysis | Pars Distalis; Pars Intermedia; Pars Tuberalis |
| Pars Intermedia | MSH-Melanocyte Stimulating Hormone |
| Neurohypophysis | Pars Nervosa; Infundibulum |
| Adenohypophyseal/Neurohypophyseal Origins | Adenohypophysis-Rathke's Pouch, Oral Ectoderm, Loses attachment with oral cavity; Neurohypophysis-Neuro Ectoderm, Outgrowth from floor of diencephalon, Remains attached to brain via infudibulum |
| Adenohypophysis | Pars Distalis - 75% of pituitary; Chromophobes; Chromophils; Secretion regulated by hypothalamic releasing hormones |
| Chromophobes | Probably undifferentiated cells |
| Chromophils | Acidophils-Somatotropes-secrete hGH (somatotropin), affects epiphyseal plates, Mammotropes-secrete prolactin, stims milk secretion; Basophils-Thyrotropes-TSH-causes thyroid hormone secretion, Gonadotropes-FSH and LH |
| FSH | Female-ovarian follicle development; Males-SErtoli cell to secrete androgen binding protein |
| LH | Females-Maturation of follicle and maintains corpus luteum; Males-called ICSH-Leydig cells secrete testosterone |
| Corticotropes | Secrete ACTH-promotes growth of adrenal cortex and secretion of glucocorticoids and gonadocorticoids |
| Pars Nervosa | hypothalamo-hypophyseal tract; axons of neurons of supraoptic and paraventricular nuclei; Herring bodies-distal tips of axons; Oxytocin-paraventricular nucleus, stims smooth m. contraction of uterus and myoepithelial cells of mammary glands |
| Pars Nervosa continued | Vasopressin (ADH)-supraoptic nucleus-acts on DCTs of kidney making more permeable to H2O, generates hypertonic urine; Pituicytes-glial-like cells found in pars nervosa |
| Hypophyseal Blood Supply | Inferior hypophyseal aa. to neurohypophysis; Hypothalamo-hypophyseal portal system-delivers hypothalamic regulating hormones to adenohypophysis, sup. hypophyseal aa. form primary capillary plexus around stalk and median eminence of hypothalamus |
| Hypophyseal Blood Supply continued | Secondary capillary plexus in adenohypophysis |
| Thyroid Gland | 2 lobes, isthmus, CT capsule, Follicles, Parafollicular cells, Hormones |
| Follicles | Structural and functional units of gland; Follicular cells-simple cuboidal; Colloid-precursor to T4(thyroxine) and T3(triiodothyronine), thyroglobulin; Only endocrine gland to store secretions (extracellularly); Regulated by TSH |
| Parafollicular Cells | Produce calcitonin; Regulated by blood Calcium levels |
| Hormones of Thyroid | Follicular hormones T3 and T4 stimulate metabolic rate; Calcitonin-lowers blood Calcium levels by inhibiting bone resorption |
| Parathyroid Glands | 2 pair-embedded on posterior of thyroid; Cords of chief cells (increase blood calcium by increasing # and activity of osteoclasts and decrease Phosphate by decreasing resorption in kidney tubules, promoting excretion) and oxyphil cells (unknown function) |
| Adrenal Glands | Paired glands superior to kidney-suprarenal glands; 2 glands in one (cortex and medulla); Adrenal cortex; Adrenal Medulla; Blood supply |
| Adrenal Cortex | From mesoderm; Synthesizes and secretes hormones only on demand; 3 layers; Zona glomerulosa-15%; Zona fasciculata-78%; Zona Reticularis-7% |
| Zona Glomerulosa | 15% of cortex; Secretes mineral corticoids-aldosterone; Maintains electrolyte and H2O balance; Regulated by renin-angiotensin system; Unaffected by ACTH |
| Zona Fasciculata | 78% of cortex; SEcretes glucocorticoids-cortisol; Preps body for max immediate energy demand, part of fight/flight stress response; Depresses immune function and inflamm. response; Regulated by ACTH |
| Zona Reticularis | 7% of cortex; |
| Pineal Gland | Epiphysis cerebri or pineal body; Pinealocytes make melatonin-involved in diurnal rhythms, innervated by ANS neurons; Brain sand-crystallinized Calcium Carbonate and Calcium Phosphate |
| Cell to cell Interactions and communication | 2 types-NS-hard wiring b/t body parts (rapid, short-lived); Endocrine-hormones-diffuse, widespread (slower, more diverse, longer-lasting) |
| Hormones | Messengers to cells; Bind to specific receptors to exert effect on target cell; Act at surface (plasma membrane) or inside (nucleus); Amplify response to small # of signaling molecules |
| Structural Classification of Hormones | Amino acid derivatives-Epi; Peptide-ADH; Protein-Insulin; Lipid-based-Steroids formed from cholesterol |
| Functional Classifications of Hormones | Growth; Rates of metabolic processes; Concentration; Stress Response |
| Distance of Effect | Endocrines-travel through blood from site of synthesis to target cell, may be distant from each other; Paracrines-relatively local, produced close to site of action, many active in inflamm. response, prostaglandins and histamine |
| Receptor Requirement for Hormone-Target Interactions | Specific interaction similar to enzyme-substrate interaction; Binding of ligand (hormone) causes changes in receptor |
| Site of hormone interaction | Steroids-Cytoplasmic or nucleic receptor, acts on nucleus, acts as gene activator-binds to enhancer region of target genes; Other Hormones-can't enter cell, bind to plasma membrane recep, signal transduction-ligand/recep complex activates 2nd messengers |
| G Protein linked membrane receptors | Binding of ligand activates G-protein |
| G-protein Structure | Alpha, beta, and gamma subunits; Alpha subunit binds GDP or GTP; Binding GTP releases Alpha from Beta-Gamma complex; Alpha-GTP can initiate signal transduction; Can act via cAMP or IP3/DAG 2nd messenger pathway |
| Tyrosine kinase receptors | Tyrosine kinase; Phosphorylates tyrosine residues; Activated by growth factors; Bound receptors aggregate in plasma membrane; Activates Kas (specific G-protein) or phospholipase C |
| Second Messengers | cAMP; IP3 and DAG; Calcium ions |
| cAMP | GTP-G-alpha activates adenylate cyclase which converts ATP to cAMP, which activates protein kinase A, which phosphorylates cellular proteins-produce different effects in different cell types-phosphodiesterase degrades cAMP |
| IP3 (inositol triphosphate) and DAG (diacylglycerol) | G protein or tyrosine kinase activates phospholipase C, which converts inositol phospholipid to IP3 and DAG, then IP3 binds to Ca channel protein and releases CA++, which binds to calmodulin and activates cell processes, |
| IP3 and DAG continued | The DAG activates protein kinase C, which phosphorylates cell proteins |
| Calcium ions | Elevated calcium binds to calmodulin; Calcium-calmodulin complex binds to kinase or phosphatase |
| Glycogen breakdown as an example of signal transduction in liver | Ligand-epi; Receptor-beta-adrenergic recep linked to G-protein; 2nd messenger-cAMP activates prot kinase A, causing cascade of phosphorylation events that ultimately activate enzymes that cleaves glycogen into glucose-1-phosphate; loss of cAMP inactivates |
| Glycogen breakdown continued | Protein kinase A and allows phosphatases to dephosphorylate enzymes, thus shutting down process |
| Urinary system function and components | Filter metabolic wastes from blood; Maintain acid/base balance; Maintain fluid and electrolyte balance; Hormone production; Pair kidneys; Pair ureters; Bladder; Urethra |
| Kidney Structure | Hilus-blood vessels, lymphatics, nn. enter and exit, renal pelvis, major/minor calyces collect urine; Cortex-renal corpuscles; Medulla-pyramids of tubules separated by cortical columns (of Bertin); Medullary Rays-columns of tubules extending to cortex |
| Kidney Structure continued | Renal Lobe-medullary pyramid and overlying cortex; Renal lobule |
| Kidney blood supply | Renal aa, interlobar aa, arcuate aa (corticomedullary junction), interlobular aa (in cortex), afferent arterioles, glomerulus, efferent arterioles, peritubular capillary plexus (surrounds tubules, vasa recta-juxtamedullary nephrons), interlobular vv, |
| Kidney blood supply continued | Arcuate vv, interlobar vv, renal vv |
| Nephron | Functional unit of kidney, renal corpuscle, PCT, loop of Henle-descending stratight portion of PCT, thin limb, ascending straight portion of DCT, DCT |
| Renal corpuscle | Glomerulus-capillary tuft; Bowman's capsule-encloses urinary space; Podocytes-visceral layer of BC-pedicels, filtration slits; mesangial cells-support cap wall and basement memb, act as phagocytes |
| Renal corpuscle filtration barrier | Endothelium of glomerular capillaries, fused basal lamina, pedicels |
| PCT | Longer than DCT; Convoluted and straight portions; Simple cuboidal with brush border; Absorbs 85% of NaCl and H2O, glucose, amino acids, and small proteins; Secretes creatinine |
| Loop of Henle | Allows production of hypertonic urine; Descending limb permeable to H2O; Ascending limb impermeable to H2O; Thick ascending limb actively transports NaCl of tubule |
| DCT | Simple cuboidal, NO brush border; Smaller cells than PCT; Macula densa-part of Juxtoglomerular apparatus; Secretes H and ammonium ions to maintain acid/base balance; responds to aldosterone by resorbing Na and secreting K |
| Collecting tubules and ducts | Cuboidal epithelium with distinct lateral borders; Vasopressin (ADH) increase permeability to H2O allowing it to return to blood; Delivers urine to renal pelvis |
| Juxtaglomerular Apparatus | Afferent arteriole-juxtaglomerular cells, modified smooth m cells, secrete renin; DCT-macula densa-narrow columnar, detect Na concentration of filtrate; Extraglomerular mesangial cells; Renin-angiotensin system |
| Renin-angiotensin system | Macula densa monitors ion concentration and communicates with JG cells; JG cells release renin; Renin converts angiotensinogen to angiotensin I(inactive) |
| Seminiferous Tubules | Spermatogenic cells (spermatogonia, spermatocytes, spermatids); Sertoli cells |
| Spermatogonia | Type A-stem cells; Type B-differentiate into primary spermatocytes |
| Spermatocytes | Divide by meiosis into spermatids |
| Spermatids | Undergo spermiogenesis to form mature spermatozoa released into lumen of tubule |
| Sertoli Cells | Rest on basal lamina; Extend width of tubule; join to form blood-testis barrier, creating basal compartment for spermatogonia and adluminal compartment for gamete development; Secretes androgen binding protein-increases local concentration of testosterone |
| Inhibin | turns off FSH release |
| MIS | During embryogenesis |
| Interstitial Tissue | Loose CT; Leydig cells-steroid-secreting, stim by LH to secrete testosterone |
| Testicular Ducts | Tubuli recti; Rete testis |
| Genital Ducts | Efferent Ductules-10 to 20, conn rete testis to epididymis, alternating ciliated/non-ciliated cells move sperm to epididymis; Epididymis-single tube, PCCE with stereocilia; Vas deferens-thick, m. wall, joins with ducts from sem. vesicles to make |
| Genital Ducts continued | ejaculatory duct, empties into prostatic urethra |
| Seminal Vesicles | Paired glands, pseudostratified columnar, secretions-high in fructose-source of energy for sperm |
| Prostate | Single midline structure containing 30 to 50 glands; Empties into prostatic urethra; Prostatic concretions increase with age; Secretion rich in lipids, proteolytic enzymes, acid phosphatase |
| Bulbourethral Glands | AKA Cowper's glands; paired glands; empty into membranous urethra; secrete mucus |
| Penis | Urethra; Erectile tissue-paired corpora cavernosa, corpus spongiosum surrounds urethra |
| Female reproductive system functions | Produce female gamete; provide environment for development of embryo and fetus |
| Female reproductive system components | Paired ovaries, paired oviducts (uterine tubes, Fallopian tubes); Uterus; Vagina |
| Ovary Structure | Germinal epi-simple cuboidal covers ovary; Tunica Albuginea-poorly defined dense CT layer deep to germinal epi; Cortex-loose CT containing follicles |
| Primordial Follicles | All follicles from birth to puberty; Primary oocyte surrounded by single layer of flattened follicular cells |
| Primary Follicle | Activated by FSH; Single layer of cuboidal follicular cells |
| Growing Follicle | Zona pellucida produced by oocyte and follicular cells; inner layer of follicular cells in contact with oocyte via gap junctions; Theca folliculi-modified stroma surrounding follicle-Theca Interna-inner, vascular; Theca Externa-Outer, fibrous |
| Antral Follicle | Accumulation of liquor folliculi; Fluid secreted by follicular cells; Cumulus oophorus-hillock of follicular cells associated with oocyte |
| Graafian Follicle | Secondary oocyte; Corona radiata-layer of follicular cells in contact with oocyte cross zona pellucida; Most mature follicle |
| Atretic Follicle | Follicle and oocyte that die without completing development; May occure at any stage of follicular development |
| Corpus Luteum | From follicular/thecal cells remaining after ovulation; temporary endocrine gland; granulosa lutein (lutein cells) from follicular cells; Theca lutein (paralutein cells) from theca interna |
| Corpus Luteum continued | Persists about 10 days then regresses and forms corpus albicans; If pregnant, persists 5mos, maintained by HCG from placenta, progesterone, relaxin-decreases contractions, softens pubic symphysis |
| Fallopian tube function | Receive oocyte; provide environment for fertilization and initial development; transport conceptus to uterus |
| Fallopian tube regions | Infundibulum; Ampulla-2/3 of tube length; Isthmus-Medial 1/3; Intramural segment extends through wall of uterus |
| Fallopian tube layers | Mucosa-longitudinal folds, simple columnar-ciliated-beat to uterus, secretory (non-ciliated)-fluid to protect ovum and promote sperm capacitation; Muscularis-inner circ, outer long, move ovum to uterus; Serosa-loose CT covered w/ mesothelium |
| Uterine structure and Layers | Structure-body, cervix; Layers-endometrium-mucosa, myometrium-muscularis (thickest, hyperplastic and hypertrophic in pregnancy), perimetrium-serosa |
| Endometrium | Simple columnar with simple tubular glands; Stratum basale-constant, source of cells for regeneration; Stratum functionalis-undergoes changes during uterine cycle |
| Stages of uterine cycle | Menstrual; Proliferative; Secretory |
| Menstrual Phase | Days 1 to 4, sloughing of stratum functionalis, cause by rapid decrease in estrogen and progesterone |
| Proliferative Phase | Days 5 to 14, regeneration of glands and epithelium from stratum basale, regeneration of blood vessels (spiral aa.) |
| Secretory Phase | Days 15 to 28, controlled by presence of progesterone, glands become highly coiled and secrete glycoproteins for nutrition upon implantation, endometrium at max thickness |
