Details Title: 24 - Urinary System Description: na Total Flash Cards: 19 Created: 04/25/2009 10:49:06		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Anatomy Flashcards
Cards in this set: Term renal corpuscle Definition this is where filtration takes place; this consists of glomerular capsule (Bowman's capsule) and enclosed glomerulus Term podocytes Definition these cells, located on the visceral layer of the glomerular capsule, cling to the glomerulus capillaries; highly modified branching cells Term thin and thick segment Definition descending and ascending loop of Henle Term cortical nephrons Definition nephrons that are located entirely in cortex Term juxtamedullary nephrons Definition these nephrons' loop of Henle go deep into medulla; produce concentrated urine Term peritubular capillaries Definition these capillaries cling closely to renal tubules and absorb solutes and water from the tubule cells Term vasa recta Definition the peritubular capillaries of juxtamedullary nephrons; they extend deep into medulla paralleling the longest loops of Henle Term juxtaglomerular apparatus Definition this is the most distal portion of ascending limb of loop of Henle; this lies against the afferent arteriole feeding the glomerulus Term granular cells Definition these muscle cells act as mechanoreceptors that sense blood pressure in afferent arterioles Term macula densa Definition chemoreceptors that that respond to changes in NaCl content; this and granular cells play important roles in regulating rate of filtrate formation Term filtration membrane Definition this membrane lies between blood and interior of glomerular capsule Term net filtration pressure Definition this pressure is responsible for filtrate formation Term glomerular hydrostatic pressure Definition force pushing water and solutes out of blood and across filtration membrane Term colloid osmotic pressure of glomerular blood and capsular hydrostatic pressure Definition two filtration - opposing forces Term glomerular filtration rate Definition volume of filtrate formed each minute by combined activity of all 2 million glomeruli of kidneys Term myogenic mechanism Definition part of renal autoregulation (intrinisc control); tendency of vascular smooth muscle to contract when stretched; increasing systemic BP causes afferent arteries to constrict which restricts flow into glomerulus; opposite when low BP Term tubuloglomerular feedback Definition (intrinsic control); directed by macula densa cells of juxtaglomerular apparatus; these cells, located on walls of ascending limb of Henle's loop, respond to filtrate concentration NaCl concentration Term sympathetic nervous system control Definition extrinsic control of filtration; during stress; neural controls constrict afferent arterioles inhibiting filtrate; this in turn trips the renin-angiotensin mechanism by stimulating macula densa Term renin-angiotensin mechanism Definition triggered when various stimuli cause granular cells to release renin which enzymatically acts on angiotensinogen converts it to angiotensin I. this turns into angiotensin II by ACE; angiotensin II stabilizes systemic BP