Test 4 A&P PDF

Urinary System Functions ● Homeostatic regulation of blood plasma ○ Blood volume & pressure (RAAS, NAD, ADH) ○ Plasma ion concentrations ○ Stabilizing blood pH ○ Conserving nutrients ● Filter fluid of blood ● Excretion ○ Removal of organic waste products such as: ○ Urea, uric acid, creatinine, hemog...

Urinary System Functions ● Homeostatic regulation of blood plasma ○ Blood volume & pressure (RAAS, NAD, ADH) ○ Plasma ion concentrations ○ Stabilizing blood pH ○ Conserving nutrients ● Filter fluid of blood ● Excretion ○ Removal of organic waste products such as: ○ Urea, uric acid, creatinine, hemoglobin end product (bilirubin), hormone metabolites, Foreign substances (drugs, pesticides etc). ● Elimination ○ Discharge of waste products into environment Anatomy Highlights (Lab Practical Study) ● Kidneys, Ureters, Urinary Bladder, Urethra, ● Retroperitoneally ○ Located within the abdominal cavity but BEHIND peritoneum ○ T12-L3 ● Kidney composed of outer cortex and inner medulla ○ Cortex = 1.25 million nephrons ○ Medulla = 6-18 renal pyramids ● 2-3 minor calyces converge into a major calyx ○ Major calyces drain urine to ureters ● Renal Anatomy ○ Nephron -> functional unit of Kidney, composed of ■ Renal corpuscle (bowman’s corpuscle + Glomerulus) ● Glomerulus (aka glomerular capillaries) ○ Fenestrated capillaries ● Bowman's Corpuscle (aka glomerular capsule) ○ Simple squamous epithelium -> parietal layer ○ Podocytes -> visceral layer ■ PCT (Proximal Convoluted Tubule) ■ Loop of Henle ■ DCT (distal convoluted tubule) ■ Collecting Duct Kidney Function ● Regulate body fluid osmolality & volume ○ Excretion of h2o and Na+ ● Regulate electrolyte balance ○ Daily intake should match daily excretion ■ Na+, K+, Cl-, HCO3-, H+, Ca2+, Mg+, PO4^3● Regulate acid-base balance ○ Coordinate with lunds on pH ● Production and secretion of Hormones ○ Renin -> angiotensinogen -> angiotensin 1 -> angiotensin 2 -> aldosterone ■ Aldosterone regulates BP via Na+ (reabsorption) and K+ (secretion) ○ EPO -> stimulate erythropoiesis in bone marrow if low O2 ○ Prostaglandins & Kinins (learning later - come back to this) Nephron & Function ● Produces filtrate from blood ● Reabsorbs organic nutrients, water and ions ● Secretes waste products into tubular fluid ● 2 Types ○ Cortical nephrons ■ 85% of nephrons (located in cortex) ○ Juxtamedullary nephrons ■ Location of countercurrent exchange mechanism (come back to this) ■ 15% of nephrons, closer to medulla and loops of henle are super deep Renal Corpuscle ○ Blood travels into afferent arteriole into renal corpuscle and out from efferent arteriole to peritubular capillaries ○ Podocytes ■ cover the lamina densa of capillaries and project into the capsular space ■ Have filtration slits Nephron Parts & Function ● PCT ○ Reabsorbs nutrients, plasma protiens and ions from filtrate ■ Released into peritubular fluid ● Loop of Henle ○ Descending & Ascending limb with thick and thin sections (come back to this) ● DCT ○ Last minute tweaks to ion, toxin and drug secretion and reabsorption ● Types of Capillaries ○ Glomerular capillaries (in the renal corpuscle; fed and drained by afferent and efferent arterioles) ○ Peritubular capillaries ■ Around the PCT, DCT and loop of henle ■ Come from the efferent arterioles ● Glomerular capillaries -> efferent arterioles ->peritubular capillaries ■ Main purpose to reabsorb solutes ■ Porous and low pressure ○ Vasa Recta (only on juxtamedullary nephrons) ■ Thin-walled and loop ■ Function = urine-concentrating mechanism Urine Production (Filtrate -> Urine) ● Filtration (glomerular filtration) ○ Filtrate of the blood plasma leaves the glomerulus ■ Filtrate must be able to pass through ALL: ● Endothelial cell fenestrations (capillary spaces) ● Basement membrane (not made of cells, just collagen and glycoprotein in between capillary and glomerular capsule) ● Filtration slits from podocytes ■ Filtrate is similar to plasma (salts, organic molecules) ■ Cell and protein free ■ Circle back on size of radius allowed to flow through ■ NO PROTEINS ○ Driven by starling forces ○ Filtration membrane is more permeable ● Reabsorption (Tubular resorption) ○ Most nutrients, water, ions reclaimed ● Secretion (Tubular secretion) ○ Active process removing undesirable substances (drugs, toxins etc) FLUID, Electrolyte, Acid-bace balance ● Big focuse is Acid-base balance (pH) ● Electrolytes -> ion, anything that conducts electricity ● Review tonicity (hypo and hyper) ○ .9% ● Water intake ○ Metabolism 10% ○ Food 30% ○ Beverages 60% ○ Only need around 5 glasses of a beverage a day ● Review ADH, aldosterone, etc hormones ● Salts are important for ○ Neuromuscular excitbaility, secretory activity… ● Osmolarity of ECF is 300mOSM, but 280 mOSM comes from sodium, ● Wherever sodium goes water follows ● ANP -> concelers out aldosterone, vassopressinn ● Aldosterone is a steroid (corticol) lipid soluble, and goes right into cell and creates chennels that allow sodium to be reabsorbed. Gets kidney to retain sodium and water folllows ● Potassium Balance ● ● ● ○ Hypokalemia is biggest threat, so we need to unload it ○ K+ excretion increases as ACF concentrations rise due to aldosterone ○ Review K+ from beginning Calcium levels ○ PTH hormone will get osteoclast to breakdown bone (review) ○ If too much, the calitonin, will put Ca+ back into bones Anion ○ “Irrelevant’ ○ Chloride follows sodium, once digested they dissociate ACID-BASE Balance (pH)** ○ Number refers to the log/exponent -> # of hydrogen per volume (gee whiz) ■ Acidic = more h+ ions ○ Arterial blood = 7.4 ■ Intracellular fluid is 7.0pH ○ Only thing that is 7pH is pure water ○ SOURCES OF HYDROGEN IONS **** slide ■ Know sources ● Most originate form cellular metabolism ■ CO2 equation and Cellular respiration equation ■ Lactic Acid -> energy source, not toxin ● Will be turned back into pyruvate ■ Ketone Bodies ● Acetone, acetoacetic acid, and betahyrodxybutyric acid ● Come from using fat as primary energy source ○ Starving, keto, or diabetic ● Ketoacidosis ■ Brain can’t use fats to make ATP, need glucose, ○ Buffer systems - hydrogen ion regulation ■ Strong acids ->dissociates 100% ● 100 molecules of HCL into solutions, every single molecule will dissociate ■ Weak acids -> ● Carbonic acid, only 5 of 100 molecules dissociate ■ Buffer systems - reist pH changes ● Different from neutralization ● Buffer system can hold onto H+ ions or unload ions until just right ● 3 buffer systems ○ Bicarbonate system is the most important ECF buffer***** ■ Reversible reaction (know equation) ■ If not enough h+ hydrogens, H2CO3 -> unloads hydrogen and HCO3- appears ■ If too much, then HCO3- + H -> H2CO3 ○ Phosphate butter system (not being tested on) ○ Proteins buffer system ■ ■ ■ ■ ■ Made up of amino acds, made of amine and carboxyl group. Have the ability to hold on to let lose a H+ ion ● If too low, H+ gets added to amine group ● If too low H+ gets unloaded from Hydroxyl group Respiratory mechanisms for pH imbalance ● Acidosis rising Co2 or H+ ● Alkalosis ● Respiratory acidosis or alkinosis -> something wrong with lungs ● CO2 should be around 40, if too high, co2 will react with water and make acid ● alkilosis ->hyperventilation result ● If too high Renal pH ● Diagram on Test ○ Dont need to know type a or type b ○ Acidosis diagram in notes ○ Alkinosis diagram in notes Metabolic pH imbalance ● Metabolic acidosis -> 2nd most common cause ○ Too much alcohol, or loss of bicarbonate ions ○ Lactic acid accumulation -> not enought O2 ○ Diabetic, starvation, kidney failure, ketoacidosis ● Metabolic alkalosis more rare ○ c=vomiting all acid contents, antiacids ESSAY Q ● Response to metabolic acidosis ○ We are going to hyperventalate, get rid of CO2, ○ Hydrogen ions bind to buffer systems (protein and sodium bicarbonate) ○ Some hydrogen ions removed by kidney and keep bicarbonate ○ Need to draw and explain (add hyperventalation) ● Response to alkalosis ○ Slow down breathing rate, unload H+ in buffer systems ○ Unload bicarbonate and keep H+ ion ○ Open Answer Q’s 1. Blood Flow through the kidney a. b. c. d. e. f. g. h. i. j. k. l. Renal artery Segmental artery Interlobar artery Arcuate artery Interlobular artery Afferent Arteriole Glomerulus Efferent arteriole Interlobular vein Arcuate vein Interlobar vein Renal vein 2. 3. 4. 5. 6. RAAS ADH GFR Calculations Flow of filtrate through nephron/kidney till Urine QUESTION a. Consumption of water is 1500ml, 750 ml from food, and 250ml from metabolism. b. Known output too 7. ESSAY Q a. Response to metabolic acidosis i. We are going to hyperventalate, get rid of CO2, ii. Hydrogen ions bind to buffer systems (protein and sodium bicarbonate) iii. Some hydrogen ions removed by kidney and keep bicarbonate iv. Need to draw and explain (add hyperventalation) b. Renal pH i. Diagram on Test ii. Say hyperventalate iii. Say buffers 1. If GFR = 135 mL/min and plasma glucose = 355 mg/dL, (work and units required for credit): a. Calculate filtered load for glucose Step 1 -> mg/dl to 135x3.55 = 479.25mg/min glucose filtering per minute Can only reabsorb 375 so. 479.25-375 = 104.25 mg/min in urine Practice Q: 125 = GFR, plasma glucose = 1 125 x1 = 125 -> normal fasting for glucose is 70-110