Filtration Glomerular I. Filtrate from plasma in glomerulusbasement mem of glom cap/ thru slits in processes of podocytes (inner layer of Bowman's capsule) A. Glomerular ultrafiltrate, formed under force of bp, low [protein] net filtration pressure = 10 mmHg
II. GFR regulated by constriction/dilation of afferent arterioles. A. Sympathetic innervation causes constriction of afferent arterioles. B. Intrinsic mechanisms autoregulate rate of renal blood flow and GFR. (V x U)/P = GFR V = rate of urine form.; u = [inulin] p =[blood inulin]
B. GFR- filtrate vol by both kidneys: 115 to 125 ml/min.; 180L/day Loop of Henle Kidney Medulla; Descending permeable to water, Lasix loop diuretic (inhibits salt/water reabsorption) out of ascending impermeable to salts, ascending vice versa limb of loop of Henle; Lasix specifically for inhibiting sodium transport Renal Pelvis collects urine from calyces and transports it to Nephron- functional unit of the kidneys, consisting of renal tubules, ureters/bladder vascular component w/ capillaries; juxtamedullary nephrons = Diuresis increased urine production concentrated urine Aldosterone principal corticosteroid hormone in electrolyte balance; Na reabsorption/K secretion in distal convoluted tubule.; stimulated by rise in blood K/indirectly by fall in blood Na; v blood flow thru kidneys enzyme renin from juxtaglomerular apparatus catalyzes angiotensin I formationconverted to angiotensin II (OCCURS IN LUNGS) stimulates adrenal cortex to secrete aldosterone; Reabsorption - Countercurrent multiplier (positive feedback) systemSpermatids four produced from one spermatocyte spermiogenesis reabsorption of remaining water (vasa recta/loop of Henle) process separating mature spermatozoa using sertoli cell/protamine protein Renal Pyramids located in medulla; separated by renal columns; empty hCG - Trophoblast cells of blastocyst secrete hCG (~LH/TSH); maintains urine into calyces that drain into renal pelvis corpus luteum for the first 10 weeks of pregnancy. Turner's Syndrome females with XO chromosomes; Klinefelter's cGMP Phosphodiesterase made by guanylate cyclase closes Ca XXY channels smooth muscle relaxation/vasodilation Gonadotropin GnRH (hypo) LH/FSH (ant. Pit); LH leydig cells testosterone; FSH sertoli cells inhibin 5-alpha reductase converts testosterone to dihydrotestosterone (DHT) FAS Ligands made by sertoli cells triggers apoptosis of T needed for development/maintenance of penis, urethra, scrotum, lymphocytes; induce death of beta cells (pancreas); prostate Colostrum secretion infant feeds on for first 2/3 days until true Amenorrhea cessation of menstrual cycle lactation; contains IgA subclass antibodies; passive immunity Grave's disease autoimmune disease; antigen = receptor proteins for Corpus luteum empty follicle LH from ant. Pit corpus luteum TSH secretes estradiol/progesterone Functions of B/T Lymphocytes I. IgG/A/M/D/E; fights bacterial infection B. Free complement proteins promote opsonization/chemotaxis and C. Antibodies + antigens promotes phagocytosis. stimulate release of histamine from tissue mast cells. III. Specific and nonspecific immune mechanisms cooperate in the II. Antigen-antibody complexes complement system. development of a local inflammation. A. Complement fixation-proteins attach to mem.; promotes cell death I. Thymus processes T lymph/secretes hormones required for effective III. Antigen presenting cells (macrophages/dendritic cells) partially digest immune response of T lymphocytes throughout body. foreign protein (virus)/present antigens to lymph on macro surface w/ A. Killer T lymph kill victim cells by w/o antibodies but requires close class-2 MHC antigens. contact bt killer T cell and victim cell. A. Helper T lymph require interaction w/ macrophages to be activated by B. Killer T lymph responsible for transplant rejection, immunological foreign antigen; when activated helper T cells secrete interleukin-2. defense vs fungal/viral infections, defense vs some bacterial infections. B. Interleukin-2 stimulates killer T cells specific to foreign antigen. C. Helper T lymph stimulate, suppressor T lymph suppress function of C. Killer T cells to attack victim cell victim cell must present foreign B lymph/killer T lymphocytes. antigen w/ class-1 MHC molecule. D. T lymph secrete lymphokines- promote action of lymph/macrophages. D. Interleukin-2 stimulates B lymph/secretion of antibodies E. Receptor proteins on T lymph cell mem bind to foreign antigen in IV. Tolerance to self-antigens due to destruction of lymph that recognize combination w/ histocompatibility antigen for T cell to become activated. self- antigens/suppression of immune response by suppressor T cells F. Histocompatibility antigens (MHC molecules)- molecules on cell mem present in different combinations in different individuals. Gastrin secreted by G cells; carried to parietal cells -> stimulates acid secretion; ECL cells to secrete histamine Bile - flows within the hepatocyte plates, in canaliculi, to the bile ducts; returned to liver in hepatic portal blood (enterohepatic circulation); bilirubin (made in spleen, liver, marrow, free-not water soluble, conjugated soluble) , bile salts (bile acids (chenodeoxycholic/cholic acid) + glycine/taurine micelle) Pepsinogen inactive form of enzyme pepsin; made by chief cells; positive feedback w/ HCl Phases of Stomach Function Cephalic (sight, smell, taste vagus nerve stimuli acid secretion; parietal cell secretion (HCl); gastrin secretion) Gastric (distension of stomach; amino acids/peptides stimulate acid secretion gastrin secretion inhibited pH<2.5) Intestinal (neural inhibition of stomach activity; chime in duo distension, ^ osmotic pressure) HDL cholesterol in liver secreted to blood as VLDL (very low density lipoprotein) triglycerides delivered to organs LDL cholesterol transport to organs; excess cholesterol returned to liver on HDL's); chylomicrons from intestine deliver lipids to dietary origins Hyperphagia lesions (destruction) of ventromedial hypo overeating; hypophagia (lateral hypo) weight loss Alpha cells (pancreas) make glucagon Lipolysis production of circulating energy substrates Lipogenesis formation of energy reserves of glycogen/fat Internal respiration gas exchange b/t blood and tissues Tidal volume volume of gas inspired/expired in unforced cycle; vital capacity max. gas expired after max insp.; functional residual capacity gas remaining after normal tidal expiration; Reverse chloride shift deoxyhemoglobin oxyhemoglobin; H+ HCO3 H2CO3 low Pco2 CO2 + H2O ; pulmonary capillaries Renal plasma threshold minimum [plasma] of substance that results in excretion of substance in urine Renal insufficiency nephrons destroyed/diabetes mellitus/arteriosclerosis hypertension (retention of salt/water) dialysis machines ADH not enough diabetes insipidus; binds to collecting duct epithelial cells cAMP as second messenger more permeability to water; ant. Pit. Stimulated by increase in blood osmolality Mast cells- release histamine/mediators of inflammation/cytokines that promote adaptive immunity; contain heparin (anticoagulant); lack of v cap permeab Neutrophils first to arrive at infection site; recruits monocytes/lymphocytes; kills microorganisms through phago; liquefies tissues creating pus; dies by apop Chemotaxis recruition to infection site by chemical attractants called chemokines Cholecystokinin (CCK) secreted by duodenum in response to chime; stimulates gallbladder contraction; pancreatic enzyme; inhibit gastric motility/secretion Gastritis inflammation when histamine secreted by mast cells secrete acid destroying mucosa; gastroenteritis- stomach/intestinal inflammation; diarrhea Treat with Oral rehydration therapy
Type I vs. type 2 diabetes mellitus- 1(under 20 years, rapid symptoms, ~5%, ketoacidosis, rare obesity, decreased insulin secretion/dead beta cells, MHC-2 cells; insulin injections; metabolic acid)2(over 40 years, slow symptom, 95%, rare ketoacidosis, common obesity, normal/increased insulin, diet/exercise) BMI w/h^2; normal = 19-25 Renal clearance ability to remove molecules from blood by excreting through urine = (V X U)/P PAH clearance of PAH can be used to measure total renal blood flow 20% of plasma flow filtered; Inulin measures GFR CAPD dialysis fluid introduced into peritoneal cavity and discarded after accumulation of wastes; less efficient, more infections vs. hemodialysis PAMPs unique to invaders to distinguish between self and foreigners; Interferon Alpha (hepB/C, leukemia)/Beta (MS) made by most cells in body; protects cells in vicinity from infection; gamma against infection, cancer Jaundice yellow staining of tissues by high blood concentrations of free/conjugated bilirubin Calcitonin inhibits resorption of Ca/phosphates in kidneys; stimulates deposition in bone; secreted by C cells of thyroid; secretion by high plasma calcium levels; acts by inhibiting osteoclast activity; stimulates urinary excretion phagocytic cells kupffer cells, microglia, macrophages Fever induced by pyrogens \delayed hypersensitivity contact dermititis Diapedesis neutrophils/monocytes leave blood/enter tissue Proteins C2-C4 needed for complement integrates innate/adaptive immune response Granzymes activate caspases that destroy cell's DNA Adjuvants molecules with immunizations have ^ antigen-presenting abilities Perforins mutations in polypeptides produced by T cells; prevent T cells from destroying cells Inhibition of cytotoxic T cells none correct Proteins 5-9 affect structure of membrane attack complex CD4 receptor on helper T cells inhibit activation by antigen presenting cells Dalton's law - total gas pressure = sum of pressures; Boyle's pressure vs. volume Henry's law - gas dissolved in fluid directly prop. to PP of gas in contact with fluid. Spleen filters blood from blood vessels; thymus is not secondary lymphoid organ Immediate hypersensitivity antibodies; delayed T cells Clonal-deletion theory toleration of self-antig through destruction of cells recognizing self-ant. Endotoxin induces NO production septic shock Glucocorticoids inhibit inter-1 stimulate immune suppression Class 1-MHC CD8 coreceptors distinguish killer T from T Helper T Class-2 MHC molecules IgE allergic reactions; MHC on chromosome 6 Interferon does not produce fever Kidney excretes bicarb in response to alkalosis; Guarding reflex True/all true Keydneys short term adjustments to maintain body ph; reg. of extracellular fluid Spironolactone inhibits aldosterone Shock-wave lithotripsy renal calculi Organic anion transporters polyspecific in proximal tube/transports drugs/toxins Polycystic kidney disease autosomal dominant inherited; renal failure Bicarbonate carbonic acid before entering kidney to reduce pH Renal clearance decreased by reabsorption, increased by secretion urea transport = passive; urea = nonsalt molecule Hypokalemia neuromuscular disorders/ecg abnormalities Conn's syndrome metabolic alkalosis/hypokalemia Apical surface of epithelia in proximal = microvilli Third filtration barrier = podocytes (cap. Fen.; basement membrane; podocytes) Alpha-tocopherol is not enzymatic protection vs. oxidative stress Antibodies vs. DNA in systemic lupus erythemato Interfer no cell division/stim. macro div; nonspec Atopic dermatitis not autoimmune disease Autoimmune disease all choices Renal insufficiency as result of arteriosclerosis Vasa recta - aquaporins Probenecid prevents excretion of antibiotics Renal damage microalbuminuria ^ bp afferent arteriole constricts Obligatory water loss = 400mL/day Vitamin D psoriasis; C wound healing Acromegaly GH oversecretion in adults Arcuate nucleus in hypo; MSH melanocortin 4 "apple shaped body" cardiovascular disease Glucagon important for fasting states Vitamin D rickets Osteoblasts synthesize hydroxyapatite in bones Success of first vaccinations Jenner Class switch recomb IgM convert to other types Monoclonal bodies show success in cancer treatm. Successful vaccine w/ attenuated virus - Pasteur Renal autoreg maintain constant GFR Efferent arteriole peritubular capillaries Renal plasma clearance < GFR Apical membranes impermeable to bicarb Uremia uretic coma; Ghrelin is not satiety factor Insulin = anabolism promotoer Adaptive thermogenesis thyroxine Oral glucose test beta cells Thyroid hormone no effect on blood glucose Stress hypoglycemia epi + glucagon Leptin/insulin = long term reg. of hunger Beta3 receptors (brown fat) Antibody diversity antigen-dependent diversity ^ Inter-3 mast cells/bone marrow stem cell grow IgG blocks synthesis of principle antibody Inter-1 by macro; stops activation of t cells Na transported out tubules Parietal layer NOT filtration barrier in glomerulus ATP/adenosine constrict afferent arteriole S2-s4 micturition center Dehydration 99.8% ultrafiltrate reabsorbed Oxidative stress excessive free radicals Stress ^ gluconeogenesis Proline not essential amino acid Somatostatin delta cells of pancreas Calcitonin antagonizes PTH Vitamin b1 beriberi; niacin pellagra Adipocytes reqd for PPAR
Chapter 15 - Defense Mechanisms I. Nonspecific defense: barriers to penetration of body/ internal defenses. A. Phagocytic cells engulf invading pathogens.
B. Antigenic determinant sites stimulate production of diff. antibodies. III. Specific immunity = lymphocytes. A. B lymphocytes secrete antibodies and provide humoral immunity. B. T lymphocytes proved cell-mediated immunity. Functions of B Lymphocytes I. five subclasses of antibodies/immunoglobulins: IgG/A/M/D/E A. Complement fixation-proteins attach to mem.; promotes cell death A. Differ in regard to polypeptides in heavy chains B. Free complement proteins promote opsonization/chemotaxis and B. Antibody has two variable regions that combine w/ specific antigens. stimulate release of histamine from tissue mast cells. C. Antibodies + antigens promotes phagocytosis. III. Specific and nonspecific immune mechanisms cooperate in the development of a local inflammation. II. Antigen-antibody complexes complement system. B. Interferon polypeptide secreted by infected cellprotect other cells II. Specific immune responses are directed against antigens. A. Antigens large, complex, and foreign molecules Active and Passive Immunity II. Passive immunity-transfer of antibodies from immune to non organism I. Primary response first exposed to pathogen A. Passive immunity occurs naturally in mother to fetus. A. Primary - IgM antibodies made slowly, and person likely to be sick B. Antiserum injections - passive to some pathogenic organisms/toxins. B. Secondary - IgG antibodies made quickly, able to resist pathogen. III. Monoclonal antibodies made by hybridomas (formed artificially by C. Active immunizations "vaccinations" fusion of B lymphs w/ multiple myeloma cells) D. Secondary bc of development of lymphocyte clones as result of antigen-stimulated proliferation of appropriate lymphocytes. Functions of T lymphocytes I. Thymus processes T lymph/secretes hormones required for effective F. Histocompatibility antigens (MHC molecules)- molecules on cell mem immune response of T lymphocytes throughout body. present in different combinations in different individuals. II. Three subcategories of T lymphocytes. III. Antigen presenting cells (macrophages/dendritic cells) partially digest A. Killer T lymph kill victim cells by w/o antibodies but requires close foreign protein (virus)/present antigens to lymph on macro surface w/ contact bt killer T cell and victim cell. class-2 MHC antigens. B. Killer T lymph responsible for transplant rejection, immunological A. Helper T lymph require interaction w/ macrophages to be activated by defense vs fungal/viral infections, defense vs some bacterial infections. foreign antigen; when activated helper T cells secrete interleukin-2. C. Helper T lymph stimulate, suppressor T lymph suppress function of B. Interleukin-2 stimulates killer T cells specific to foreign antigen. B lymph/killer T lymphocytes. C. Killer T cells to attack victim cell victim cell must present foreign D. T lymph secrete lymphokines- promote action of lymph/macrophages. antigen w/ class-1 MHC molecule. E. Receptor proteins on T lymph cell mem bind to foreign antigen in D. Interleukin-2 stimulates B lymph/secretion of antibodies combination w/ histocompatibility antigen for T cell to become activated. IV. Tolerance to self-antigens due to destruction of lymph that recognize self- antigens/suppression of immune response by suppressor T cells Tumor Immunology I. Immune surveillance vs cancer provided by killer T/natural killer cells B. Natural killer cells nonspecific, T lymphocytes specific C. Immunological surveillance vs cancer weakened by stress. A. Cancerous cells dedifferentiate/produce fetal antigens antigens presented to lymph w/ abnormal class-2 MHC antigens. Diseases Caused by the Immune System I. Autoimmune diseases caused by production of autoantibodies vs selfA. Immediate hypersensitivity = allergen stimulates IgE antibodies antigens/result from development of autoreactive T lymphocytes. attach to tissue mast cells/stimulate release of chemicals from mast cells. II. Immune complex diseases caused by inflammationfree antigens= B. Mast cells secrete histamine, leukotrienes, prostaglandins, produce bound antibodies. allergy symptoms III. Two types of allergic responses: immediate/delayed hypersensitivity C. Delayed (contact dermatitis)- T cell-mediated response Chapter 16 - The Respiratory System I. Alveoli - thin-walled air sacs that provide large sa for gas diffusion. A. Structures of cavity covered by thin, wet pleural membranes. A. Respiratory Zone - region of lungs where gas exchange with the blood B. Lungs covered by visceral pleura (normally against parietal pleura that B. Conducting zone - trachea, bronchi, and bronchioles deliver air to ^ lines chest wall) II. Thoracic cavity limited by chest wall and diaphragm. C. Intrapleural space - potential space bt visceral/parietal pleurae Physical Aspects of Ventilation I. Intrapleural/intrapulmonary pressures vary during ventilation. B. Elasticity= tendency to recoil after distension. A. Intrapleural pressure always less than intrapulmonary pressure. C. Fluid surface tension in alveoli exerts inward force resist distension B. Intrapulmonary-<atmospheric=inspiration, >atmospheric = expiration. A. Collapse of alveoli bc pressure caused by surface tension > smaller C. Boyle's law - inverse relationship bt volume/pressure of gas alveoli than large alveoli law of La Place. II. Mechanics of ventilation influenced by physical properties of lungs. B. Pulmonary surfactant (phospholipid+protein) lowers surface tension A. Compliance=ease of expansion- bt intrapulmonary/pleural pressure C. Hyaline mem. disease - lungs of premature collapse bc no surfactant. Mechanics of Breathing II. Spirometry aids diagnosis of pulmonary disorders. I. Inspiration/expiration contraction/relaxation of striated muscles. A. Pulmonary fibrosis - restrictive disease; vital capacity < below normal A. Quiet ins. diaphragm/external intercostal muscles contract B. Asthma/bronchitis - obstructive disease; forced expiratory volume increase thorax volume below normal bc of increased airway resistance to air flow. B. Quiet ex. muscles relax elastic recoil of lungs/thorax III. Asthma bronchoconstriction; emphysema/chronic bronchitis decrease in thoracic volume. referred to as chronic obstructive pulmonary disease. C. Forced ins/ex aided by contraction of accessory respiratory muscles. Gas Exchange in the Lungs I. Dalton's law - total pressure of gas = sum of pressures of each gas A. [O2/CO2] dissolved in plasma = prop. to electric current generated by A. Partial pressure of gas in dry gas mixture = total pressure x % comp. special electrodes that react with gases. of gas in mixture. B. Normal arterial PO2 = 100 mm Hg [dissolved O2] = .3 ml/100 ml B. Total pressure of mixture decreases with altitude above sea level blood; O2 in red blood cells (19.7 mL/100 ml blood) does not affect P O2 partial pressures of constituent gases decrease with altitude. III. PO2 /PCO2 measurements of arterial blood provide info on lung function IV. Blood flow (perfusion) in lungs must adequate/match air flow C. Partial pressure of wet gas mixture water vapor pressure added (ventilation) for adequate gas exchange to occur. II. Henry's law - amount of gas dissolved in fluid is directly prop. to partial pressure of that gas in contact with the fluid. V.High gas PP O2 toxicity, nitrogen narcosis, decompression sickness
I. Rhythmicity center in med oblongata controls muscles of respiration. Regulation of Breathing B. Central chemoreceptors in med oblong sensitive to in blood P CO2 because resultant changes in pH of the cerebrospinal fluid. A. Ins/Ex neuron activity varies reciprocallyautomatic breathing cycle C. Peripheral chemoreceptors in aortic/carotid bodies sensitive to in B. Activity in med influenced by apneustic / pneumotaxic center in pons, blood PCO2 bc of changes in blood pH. as well as by sensory feedback information. III. Decreases in blood PO2 stimulate breathing only when <50 mm Hg; C. Conscious breathingcontrol by cere cortex via corticospinal tracts stimulates breathing thru chemoreceptors sensitive to in P CO2 and pH. II. Breathing affected by PO2, pH, PO2 of blood chemoreceptors IV. Tidal volumes of > 1 L ins inhibited by stretch receptors in lungs A. PCO2 of blood/changes in pH > blood PO2 in regulation of breathing. (the Hering Breuer reflex) A similar reflex may act to inhibit expiration. Hemoglobin and Oxygen Transport I. Hemoglobin-2 alpha/beta polypeptide chains + four heme groups w. Fe C. Affinity decrease oxy dissociation curve shift right (greater % A. Deoxyhemoglobin - Iron reduced w/o O2; Oxyhemoglobin = w/ O2 unloading of oxygen to the tissues) B. Carboxylhemoglobin Fe + CO; Methemoglobin oxidized Fe IV. Oxygen affinity decreased by organic molecule in rbc - 2,3-DPG /unable to transport any gas A. Oxy inhibits 2,3-DPG production [2,3-DPG] increases when C. Deoxy + O2 in lungs (loading reaction); breaks bonds in tissue cap anemia or low PO2 (as in high altitude) causes decrease in oxy (unloading reaction) extent determined by PO2 and O2 affinity B. Anemic low [hemoglobin] compensated partially for bc ^ % oxy II. Oxy dissociation curve - percent oxy saturation at diff values of P O2 unload oxygen as result of 2,3-DPG. A. At rest, arterial/venous saturation~22% of oxy unloads O2 to tissue C. Fetal hemoglobin cannot bind to 2,3-DPG ^ O2 affinity than mom B. Exercise venous PO2 /% oxy saturation decrease ^% oxy unload transfer of oxygen to fetus. III. pH/temp influence oxygen affinity extent of loading and unloading. V. Inherited amino acid defects in hemoglobin responsible for sickle-cell A. Bohr Effect - < pH decreases affinity and rise in pH increases affinity. anemia and thalassemia. B. Rise in temp decreases affinity VI. Striated muscles have myoglobin, related to hemoglobin, combine with O2/deliver to muscle cell mitochondria at low P O2 values. Carbon Dioxide Transport and Acid-Base Balance I. Rbc contain carbonic anhydrasecatalyzes CO2+H2Ocarbonic acid. D. Reverse chloride shift in lungs low PCO2 favors conversion of A. Favored by high PCO2 in tissue capillaries CO2 produced by tissue carbonic acid to CO2 exhaled. converted into carbonic acid in red blood cells. II. Adjust [blood CO2 carbonic acid] ventilation maintains proper B. Carbonic acid ionizes to form H+ and HCO3- (bicarbonate). acid-base balance of blood. C. H+ buffered by hemoglobin but more bicarbonate diffuse outward A. Normal arterial blood pH is 7.40; <7.35 = acidosis, >7.45 = alkalosis. electrical gradient established draws Cl- into rbc chloride shift. B. Hyperventilationresp alkalosis; hypoventilationresp acidosis. C. Met acidosishyperventilationresp alkalosis =partial compensation Effect of Exercise and High Altitude on Respiratory Function II. Acclimatization to high altitude = help to deliver O2 effectively to I. Exercise=^ventilation (hyperpnea)^ met rate so art blood PCO2 normal tissues, despite reduced arterial PO2. A. Hyperpnea bc of proprioceptor info, cerebral input, art P CO2 /pH. A. Low PO2 Hyperventilation B. Heavy exerciseanaerobic threshold reached at ~55% of max O2 B. Rbc ^ 2,3-DPG v O2 affinity and improves unloading reaction. uptake lactic acid released into blood by muscles. C. Kidneys produce hormone erythropoietin stimulates bone marrow C. Endurance trainingmuscles utilize O2 more effectively ^ levels of to ^ rbc so more oxygen can be carried by blood at given values of P O2. exercise performed before anaerobic threshold reached. Chapter 17 Structure and Function of the Kidneys I. kidney divided into outer cortex and inner medulla. B. Glomerular blood drained by efferent arteriole - delivers blood to A. Medulla = renal pyramids separated by renal columns. peritubular capillaries surrounding nephron tubules. B. Renal pyramids empty urine into calyces that drain into renal pelvis C. Glomerular (Bowman's) capsule/proximal&distal tubules in cortex. D. Loop of Henle in medulla. urine flows into ureter and transported to bladder to be stored. II. 1 kidney = million+ func. Units- nephrons vascular/tubular comp. E. Distal tubule collecting ducts thru med to empty urine into calyce A. Filtration occurs in glomerulus - receives blood from afferent arteriole Glomerular Filtration B. Glomerular filtration rate (GFR) - volume of filtrate by both kidneys I. Filtrate from plasma in glomerulusbasement mem of glom cap/ thru each minute; 115 to 125 ml/min. slits in processes of podocytes (inner layer of Bowman's capsule) II. GFR regulated by constriction/dilation of afferent arterioles. A. Glomerular ultrafiltrate, formed under force of bp low [protein] A. Sympathetic innervation causes constriction of afferent arterioles. B. Intrinsic mechanisms autoregulate rate of renal blood flow and GFR. Reabsorption of Salt and Water I. 65% of filtered salt/water reabsorbed across proximal tubules. C. Salt transport/CCE in vasa recta tissue fluid of med= hypertonic A. Na actively transported, Cl follows passively, water follows salt out D. Hypertonicity of med multiplied by positive feedback mechanism in B. Salt transport in proximal tubules not under hormonal regulation. descending limb passively permeable to water and perhaps to salt. II. Countercurrent multiplier system-reabsorption of remaining water III. Collecting duct permeable to water but not salt. A. Na actively extruded from ascending limb passively by chloride. A. Collecting ducts thru hypertonic medh20 leaves by osmosis cap . B. Ascending limb impermeable to h20remaining filtrate = hypotonic. B. Permeability of collecting ducts to water stimulated by ADH Renal Plasma Clearance III. Almost all PAH going through kidneys cleared by filtration/secretion I. Inulin filtered but not reabsorbed/secreted clearance = GFR PAH clearance = total renal blood flow. II. Some filtered urea reabsorbed clearance < GFR IV. Normally all filtered glucose reabsorbed; glycosuria - transport carriers for glucose become saturated as a result of hyperglycemia. Renal Control of Electrolyte and Acid-Base Balance IV. Nephrons filter bicarbonate/reabsorb amount required to maintain I. Aldosterone Na reabsorption/K secretion in distal convoluted tubule. acid-base balance. Reabsorption of bicarbonate is indirect. II. Aldosterone stimulated by rise in blood K/indirectly by fall in blood Na A. Filtered bicarbonate + H+ carbonic acid in filtrate. A. v blood flow thru kidneys enzyme renin secreted from B. Carbonic anhydrase in microvilli mem in tubules catalyzes carbonic juxtaglomerular apparatus. acid to carbon dioxide and water. B. Renin catalyzes angiotensin I formationconverted to angiotensin II C. CO2 reabsorbed/converted in tubule cells/rbc to carbonic acid C. Angiotensin II stimulates adrenal cortex to secrete aldosterone. dissociates to bicarbonate and H+. III. Aldosterone stimulates secretion of H+/K into filtrate for Na D. Nephron filter/secrete H+ excreted/buffered by ammonium/phosphate
Clinical Applications I. Diuretic drugs increase urine volume lower blood volume/pressure. B. Osmotic diuretics - extra solutes in filtrate ^osmotic pressure of A. Loop diuretics/thiazides inhibit active Na+ transport in ascending limb filtrate and inhibit osmotic reabsorption of water. and early portion of the distal tubule C. K-sparing diuretics- distal tubule inhibited to reabsorb Na + /secrete K. II. Glomerulonephritis - glomeruli leaks plasma proteins into the urine. III. Renal dialysis used to treat people with renal insufficiency. Chapter 18 - Introduction to the Digestive System I. Digestion of food - hydrolysis of molecules into subunits. A. Mucosa- simple columnar epithelium, connective tissue called lamina A. Occurs in lumen of GI tract and is catalyzed by specific enzymes. propria, smooth muscle called muscularis mucosa. B. Digestion products absorbed thru intest. mucosa; enters blood/ lymph B. Ssubmucosa - connective tissue; muscularis- smooth muscles; serosa II. Layers (tunics) of GI tract (from inside outward): mucosa, submucosa, connective tissue covered by the visceral peritoneum. muscularis, and serosa. C. Submucosa - submucosal plexus/muscularis -myenteric plexus of autonomic nerves. Esophagus and Stomach I. Peristalsis push food thru lower esophageal sphincter into stomach. B. Parietal cells of gastric gland HCl; chief cells pepsinogen II. Stomach - cardia, fundus, body, and pyloris (antrum); pylorus w/ C. Acidic environ. pepsinogen protein- digesting enzyme (pepsin) pyloric sphincter. D. Some protein digestion in stomach; most important stomach functionA. Lining of stomach folds (rugae)/mucosal surface forms gastric pits secretion of intrinsic factor needed for B12 absorption in intestine. gastric glands. Small Intestine A. New epithelial cells are formed in crypts. I. Small intestineduodenum, jejunum, and ileum; common bile duct/ B. Membrane of intestinal epithelial cells folded into microvilli = brush pancreatic duct empty into duodenum. border of mucosa and serves to increase surface area. II. Villi project into lumen; at base of villi- mucosa forms narrow pouches III. Dig. enzymes (brush border enzymes), located in microvilli membrane called crypts of Lieberkuhn. IV. Small intestine exhibits - peristalsis and segmentation. Large Intestine I. Large intestine divided into cecum, colon, rectum, and anal canal. A. Most water absorbed in small intestine, but 1-1.5 L/day pass to large A. Appendix attached to inferior medial margin of the cecum. intestine absorbs about 90% of this amount. B. Colon - ascending, transverse, descending, and sigmoid portions. B. Na+ actively absorbed/water follows passively, ~kidneys C. Haustra - bulges in walls of the large intestine III. Anal sphincters relax/other muscles contract ^ rectal pressure II. Large intestine absorbs water and electrolytes. defecation Liver, Gallbladder, and Pancreas I. Liver - largest internal organ - functional units called lobules. G. Modifies plasma concentrations of proteins, glucose, triglycerides, A. Liver lobules - plates of hepatic cells separated by capillary sinusoids. and ketone bodies. B. Blood flow from periphery of each lobule (where hepatic artery/portal II. Gallbladder stores/concentrates bile released thru cystic/common vein empty) thru sinusoids and out central vein. duct to the duodenum. C. Bile flows within the hepatocyte plates, in canaliculi, to the bile ducts. III. Pancreas - exocrine and endocrine gland. D. Substances excreted in bile returned to liver in hepatic portal blood; A. Endocrine - islets of Langerhans secrete hormones insulin/glucagon. this is called enterohepatic circulation. B. Exocrine acini of pancreas make pancreatic juice (contains various E. Bile- bilirubin, bile salts, cholesterol, and other molecule digestive enzymes and bicarbonate) F. Detoxifies blood by excreting substances in bile by phagocytosis/ chemical inactivation Neural and Endocrine Regulation of the Digestive System I. Regulation of gastric function occurs in three phases. B. Short reflexes include gastroileal reflex, ileogastric reflex, and intestino-intestinal reflexes. A. Cephalic phase - higher brain centers act via vagus nerve III. Hormones secretin and CCK regulate pancreatic juice/bile secretion. stimulates gastric juice secretion. A. Secretin secretion by arrival of acidic chyme into duodenum B. Gastric phase - secretion of HCl and pepsin, controlled by gastric B. CCK secretion by presence of fat in chyme arriving in the duodenum. contents/hormone gastrin, secreted by gastric mucosa. C. Contraction of gallbladder in response to neural reflex and to CCK C. Intestinal phase- stomach activity inhibited by neural reflexes/ secretion by duo hormonal secretion from duodenum. IV. Gastrointestinal hormones needed for maintenance of GI tract/ II. Intestinal function regulated by local short reflexes. accessory digestive organs. A. Submucosal/myenteric plexuse-autonomic motor/sensory/interneurons Digestion and Absorption of Carbohydrates, Lipids, and Proteins I. Starch digestion begins in mouth through salivary amylase. III. Lipids digested in small intestine after being emulsified by bile salts. A. Free fatty acids/monoglycerides enter micelles (formed in bile salts)/ A. Pancreatic amylase digests starchdisaccharides/short-chain absorbed in this form or as free molecules. oligosaccharide B. Complete digestion into monosaccharides by brush border enzymes. B. Inside mucosal epi cells subunits used to resynthesize triglycerides II. Protein digestion begins in stomach through pepsin. C. Triglycerides in epithelial cells + proteins chylomicrons - secreted A. Pancreatic juice - protein-digesting enzymes trypsin, chymotrypsin. into the central lacteals of the villi. B. Brush border - digestive enzymes help complete digestion of proteins D. Chylomicrons transported by lymph to thoracic duct and enter blood. C. Amino acids, like monosaccharides, absorbed/secreted into cap blood entering the portal vein. Chapter 19 - Nutritional Requirements A. Metabolic rate influenced by physical activity, temp, eating; basal II. Vitamins and elements serve as cofactors and coenzymes. metabolic rate measured as rate of oxygen consumption when influences A. Vitamins divided into fat-soluble (A, D, E, and K) and water-soluble. standardized and minimal. B. Water-soluble vitamins needed for enzymes involved in cell resp. B. Energy from food/energy consumed by body measured in kilocalories C. Fat-soluble vitamins A and D have specific functions but share similar mechanisms of action, activating nuclear receptors and regulating genetic C. Caloric intake> energy expenditure excess calories stored as fat. expression. Regulation of Energy Metabolism I. Body tissues use circulating energy substrates (glucose, fatty acids, A. Different organs have different preferred energy sources. ketone bodies, lactic acid, amino acid) for cell respiration.
B. Circulating energy substrates obtained from food or energy reserves of A. Children- circulating saturated fatty acids promote cell division and glycogen, fat, and protein in body differentiation of new adipocytes activity involves bonding of II. Eating behavior is regulated by hypothalamus. prostaglandin, 15d-PGJ2, with nuclear receptor PPARg. A. Lesions of ventromedial area of hypo produce hyperphagia; B. Adipocytes secrete leptin (regulates food intake/metabolism) and lesions of lateral hypothalamus produce hypophagia. TNFa (regulate sensitivity of skeletal muscles to insulin) B. NT implicated in control of eating behavior (endorphins, norepi, IV. Control of energy balance in body regulated by anabolic/catabolic serotonin, and cck) effects of a variety of hormones. III. Adipose cells, or adipocytes, are targets of hormonal regulation endocrine in nature. Energy Regulation by the Islets of Langerhans I. ^ [plasma glucose] stimulates insulin and inhibits glucagon secretion. B. Skeletal muscles - major organs removing glucose A. Amino acids stimulate secretion of insulin and glucagon. III. Fasting insulin secretion decreases and glucagon secretion^ B. Insulin secretion stimulated by parasymp innervation of islets/action A. Glucagon glycogenolysis in the liver, gluconeogenesis, lipolysis, of intestinal hormones (gastric inhibitory peptide (GIP)) and ketogenesis. II. Intestinal absorption - insulin promotes uptake of blood glucose B. Help maintain levels of blood glucose for brain/provide alternate A. Lowers [blood glucose] and ^ reserves of glycogen, fat, protein. energy sources for other organs. Diabetes Mellitus and Hypoglycemia I. Diabetes mellitus/reactive hypoglycemia represent disorders of islets B. Non-insulin-dependent diabetes mellitustissue insensitivity to A. Insulin-dependent diabetes mellitus occurs when beta cells destroyed; insulin/inadequate insulin; aggravated by obesity/improved by exercise. lack of insulin/excessive glucagon secretion C. Reactive hypoglycemia occurs when islets secrete excessive amounts of insulin in response to a rise in blood glucose concentration. Metabolic Regulation by Adrenal Hormones, Thyroxine, and Growth Hormone I. Adrenal hormones in energy regulation- epi from adrenal med and B. Promotes protein syn./needed for body growth/development (CNS) glucocorticoids (hydrocortisone) from adrenal cortex. III. Secretion of growth hormone regulated by releasing/inhibiting hormones from hypo A. Effects of epi similar to glucagon stimulates glycogenolysis/ A. Stimulated by protein meal/fall in glucose (fasting) lipolysis activates ^ metabolism of brown fat. B. GH stimulates catabolism of lipids/inhibits glucose utilization. B. Glucocort-breakdown of muscle protein/conversion of amine C. GH stimulates protein synthesis body growth. glucose in liver. D. Anabolic effects (bone growth in childhood) produced indirectly via II. Thyroxine stimulates rate of cell resp in almost all cells in the body. polypeptides called insulin-like growth factors, or somatomedins. A. Thyroxine sets basal metabolic rate (BMR) (rate at which energy (and oxygen) consumed by body under resting conditions) Regulation of Calcium and Phosphate Balance A. Last hydroxylation step is stimulated by PTH I. Bone Ca/phosphate in hydroxyapatite crystals reserve supply B. 1,25-dihydroxyvitamin D3 stimulates intestinal absorption of calcium A. Formation/reabsorption of bone by osteoblasts/osteoclasts, respectivel and phosphate, resorption of bone, and renal reabsorption of phosphate. B. [plasma Ca/phosphate] affected by intestinal absorption/urinary excretion of these ions. IV. ^ PTH ^ 1,25-dihydroxyvitamin D3 production maintain proper blood levels of Ca/phosphate in response to a fall in calcium levels. II. PTH - bone resorption/calcium reabsorption in kidneys raises [Ca] V. Calcitonin secreted by parafollicular cells of thyroid gland. A. Secretion of PTH stimulated by fall in blood calcium levels. A. Secretion stimulated by rise in blood calcium levels. B. PTH inhibits reabsorption of phosphate in kidneys more is excreted B. Calcitonin lowers blood calcium by inhibiting bone resorption and III. 1,25-dihydroxyvitamin D3 derived from vitamin D by hydroxylation. stimulating the urinary excretion of calcium and phosphate. Chapter 20 - Sexual Reproduction B. Testes of male embryo secrete testosterone/mllerian inhibitory factor. A. Female accessory sex organs- uterus and uterine (fallopian) tubes. B. Testosterone (via conversion to dihydrotestosterone) promotes MIF no female acces. sex organs/testosteronemale acces. sex organs. formation of male external genitalia; female genitalia formed when absent. II. Male accessory sex organs - epididymis, ductus (vas) deferens, seminal vesicles, prostate, and ejaculatory duct. Endocrine Regulation of Reproduction I. Gonads stimulated by ant pit hormones: FSH and LH II. ^ FSH /LH secretion at puberty due to maturational changes in brain and v sensitivity of hypo/pit gland to negative feedback effects A. Secretion stimulated by GnRH hypothalamus. B. FSH/LH secretion under control of gonads by negative feedback III. Pineal gland secretes melatonin inhibitory effect on gonadal exerted by gonadal steroid hormones and by a peptide called inhibin. function in some mammals, but role in human physiology controversial. Male Reproductive System I. LH secretion- negative feedback from testos, FSH inhibin from testes III. Diploid spermatogonia in sem tubules meiosis haploid sperm. A. Testosterone conversion to 5a-reduced androgen/estradiol. A. Four spermatids formed develop into spermatozoa by maturational B. Secretion relatively constant and does not decline sharply process called spermiogenesis. II. Testosterone promotes growth of soft tissue/bones before epiphyseal B. Sertoli cells in seminiferous tubules required for spermatogenesis. discs have sealed = anabolic steroids. C. Puberty testos needed for meiosis/FSH spermiogenesis. A. Secreted by interstitial cells of Leydig under stimulation of LH. IV. Spermatozoa in semin tubulesepididymisdrained from epididymis B. LH receptor proteins located in interstitial tissue. FSH receptors in into ductus deferens; prostate and seminal vesicles add fluid to the semen. Sertoli cells in seminiferous tubules. V. Penile erection produced by parasymp-induced vasodilation. C. Leydig/Sertoli cells secrete autocrine regulatory molecules interact Ejaculation produced by symp stimulation of peristaltic contractions Female Reproductive System I. Human sexual response excitation, orgasm, plateau, and resolution. A. Ovulation secondary oocyte extruded from ovary does not II. Primordial follicles in ovary have primary oocytes (arrested at prophase complete second meiotic division unless fertilized. of first meiotic division) B. After ovulation - empty follicle endocrine gland corpus luteum. A. Small # of oocytes stimulated to complete first meiotic division 2 C. Ovarian follicles secrete only estradiol, Corpus luteum secretes both estradiol and progesterone. B. Secondary oocyte- complete cell formed other product- polar body IV. Hypo secretes GnRH in pulsatile fashion pulsatile secretion of III. One of secondary follicles grows large graafian follicle ovulated. gonadotropins needed to prevent desensitization Menstrual Cycle I. Follicular phase, ovarian follicles stimulated by FSH from ant pit A. Follicles grow, mature, and secrete increasing amounts of estradiol.
B. Day 13 rapid ^ in estradiol LH surge from ant pit (+) feedback C. LH surge stimulates ovulation at about day 14. D. After ovulation, LH stimulation corpus luteum luteal phase E. Progesterone/estradiol secretion ^ during luteal phase; (-) feedback on FSH and LH secretion.
F. No continued stimulation by LH corpus luteum regresses at end of luteal phase estradiol/progesterone declines menstruation/new cycle II. ^ [estradiol] during follicular phase proliferative phase of endometrium; progesterone secretion during luteal phase secretory III. Oral contraceptive pills contain estrogen/progesterone negative feedback control of FSH and LH secretion. Fertilization, Pregnancy, and Parturition IV. Contraction of uterus in labor stimulated by oxytocin from post pit/ I. Sperm acrosomal reaction penetrate corona radiata/zona pellucida. prostaglandins, produced within the uterus. A. Fertilizationsecondary oocyte completes meiosis second polar A. Androgens, primarily DHEA, secreted by fetal adrenal cortex body converted to estrogen by placenta. B. Diploid zygote undergoes cleavage to form a morula blastocyst. B. Estrogen from the placenta induces oxytocin; enhances uterine Implantation of blastocyst in endometrium begins bt fifth and seventh day. sensitivity/promotes prostaglandin synthesis in uterus labor/delivery. II. Trophoblast cells of blastocyst secrete hCG (~LH); maintains corpus V. High levels of estrogen during pregnancy stimulate growth and luteum for the first 10 weeks of pregnancy. development of mammary glands. B. O2, nutrients, wastes exchanged by diffusion bt fetal/maternal blood. A. Prolactin (prolactin-like hCS) stimulate milk protein production III. Placenta secretes hCS, hCG and steroid hormones. Prolactin secretion/action blocked during pregnancy by ^ estrogen A. hCS similar to prolactin/GH; hCG similar to LH/TSH. B. After delivery, estrogen levels fall, prolactin milk production. B. Major steroid hormones secreted by placenta - estriol. Placenta/fetal glands cooperate in production of steroid hormones. C. Milk-ejection reflex- neuroendocrine reflex - stimulus of suckling reflex secretion of oxytocin ejection of milk from the nipple.