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20 Cards in this Set
- Front
- Back
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resistance vessels of kidney
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afferent & efferent
interlobar (16%) |
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capillaries of kidney
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glomerular
-high pressure -60 mmHg Peritubular -low pressure -20 mmHg -capsule creates outward hydrostatic pressure -oncotic pressure supports resoption |
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Types of cells in the kidney
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JG
-on afferents -secrete renin Mesangial -contractile -respond to hormones Macula Densa (TG Feedback) -maintain filtration rate regardless of systemic pressure -sense filtrate concentration -contract/relax afferents -signal for release of renin |
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function of vasa recta
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surround juxtamedullary loops
create concentration grad in medulla (10% nephrons are JM) |
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Regulation of renal blood flow
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Auto
-Myogenic tone -Tubuloglomerular feedback External -Sympathetic -RAS (AT II, Aldost) -Hormones (ADH, ALdost, Endothelin, PGs, NO, ANP) |
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Myogenic tone
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-response to stretch
-buffer from systemic changes -stretch then Ca rls |
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Tubuloglomerluar (TG) feedback
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-macula densa in distal tubule
-sense decreased filtrate (NaCl) -signal for decreased tone in affs -signal for release renin |
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increase sensitivity of TG feedback
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-volume contraction
-adenosine -PGE2 -TXA1 -HETE -AT II |
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decrease sensitivity of TG feedback
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-volume expansion
-ANP -NO -cAMP -PGI2 -high-protein diet |
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sympathetic regulation of renal blood flow
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alpha 1 R's
-constrict renal bv's -via PLC -decreases renal BF beta 1 R's -renin secretion -via cAMP -inhibited by high Ca -augmented by low Ca |
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renin secretion
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-cAMP from beta 1 R's on JG's
-low Na at macula densa -fall in stretch, shear -inhibited by high IC Ca (eg from stretch) |
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production of AT II
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renin release
cleaves angiotensinogen (from liver) AT I not active ACE in endos (mostly lung) cleaves to AT II |
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actions of AT II
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-stim rls aldosterone
-stim vasoconstriction -stim rls ADH INCREASES ECF VOLUME (thirst, Na & water reten, vasoconstrict) |
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affect of AT II at heart
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constrict arteries via AT 1 R's (ARB's)
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affect of AT II on NS
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-increase epi/NE rls at PNS & CNS
-stim ADH secretion |
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effect of ET 1 binding ETA
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constrict cortical arteries
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effect of ET 1 binding ETB
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inhibit Na reabsorption at DT
dilate medullary arterioles |
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Loss of ETB Rs causes...
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Na retention
HTN |
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loss of ETA Rs causes...
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lower BP & increased renal flow
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affect of PGs on kidney
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none if healthy
surgery or High AT II levels (volume or Na depletion) PG induces vasodilation COX inhibitors cause dramatic renal function |
