BIOL373 MIDTERM 2 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED ++

BIOL373 MIDTERM 2 EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED ++ Roles of the kidney regulation of ECF and BP regulation of plasma osmolarity regulates ion balance regulates plasma pH excretion of waste endocrine functions How much of cardiac output goes to the urinary tract? 20-25% Venus Portal System Circulation artery arteriole capillary venule capillary venule vein heart - conventional circulation only has 1 capillary and 1 venule How many capillary beds does a nephron have? two, glomerulus and peritubular capillaries Main difference between cortical and juxtamedullary nephrons JM nephrons have vasa recta, aka straight vasculature along its loop of Henle How much plasma do kidneys process per day? 180L but urine output is only 1.5L/day Filtration movement of water/solutes from blood into tubules - only occurs in renal corpuscles - once in tubules, filtrate will be excreted unless reabsorbed Reabsorption movement of water/solutes from filtrate back into blood - occurs in peritubular capillaries Secretion removing molecules from blood, adding them to filtrate - much more selective than filtration Filtration fraction % of total plasma volume that filters into tubule Which proteins are uniquely expressed in kidneys podocin and nephrin What does pi mean in glomerular filtration colloid osmotic pressure gradient due to proteins in plasma but not in capsule What range of mean arterial pressure are nephrons able to autoregulate at? ~ 80 - 180 mm Hg What is excretion formula Filtration - Reabsorbed + Secretion Macula densa cells modified tubular epithelium that sense and respond to NaCl; if NaCl is high the cell considers the GFR is high as well Juxtaglomerular Apparatus cells modified arteriolar wall which are specialized smooth cells Hormone chemical messenger secreted into the blood by specialized cells; regulate long-term and/or on-going fx Endogenous generated from within; therefore endocrine glands can only secrete their product to the blood stream Exogenous generated from outside, therefore exocrine glands can secrete out onto epithelial surfaces Classical Approaches in Experimental Endocrinology - ablate: remove expected gland - replace: gland or extract of gland - create situation of excess: isolate active substance and chemically characterize First formal experiment in endocrinology