Flashcards in Physiology 3 Deck (19):
How and when does the juxtaglomerular apparatus increase renin release?
The macula densa release Renin in response to:
- beta-1-adrenergic stimulation
- decreased perfusion pressure
- decreased NaCl at the DCT (macula densa)
How and when does the JGA decrease GFR?
Increased NaCl reabsorption at the macula densa (DCT) causes the constriction of the afferent arteriole and slight dilation of the efferent.
Why doesn't Ang II cause reflex bradycardia?
It inhibits baroreceptors.
What peptide released by the heart acts as a check on the renin-angiotensin-aldosterone system?
If the blood osmolality is too low, but the blood volume is also too low, will ADH be secreted?
yes, blood volume takes precedence
Why would renal artery stenosis cause an increaes in blood pressure?
Renin release by JG cells
How do NSAIDs cause ACUTE renal failure?
prevent renal PG production, preventing dilation of the afferent arteriole and lowering GFR.
Effects of ANP
up GFR, up Na secretion at PCT w/ no compensatory reabsorption at distal nephron
PTH increases Ca++ reabsorption at the ____.
PTH causes decreased PO4--- reabsorption at the _____.
Aldosterone acts at the _______ to translocate _______ channels to the luminal membrane.
collecting duct (principal cell), Na+
PTH increases proton secretion from the _______ cells of the collecting duct.
What acid-base disturbance will hyperaldosteronism cause? Why?
metabolic alkalosis d/t increased H+ excretion at the collecting duct
Etiology of Type 1 (distal) renal tubular acidosis?
In ability to secrete H+ at DCT.
risks associated w/ RTA 1
hypokalemia and Ca++ kidney stones
Etiology of Type 2 (proximal) RTA?
Inability to reabsorb HCO3- at the PCT
risks associated w/ type 2 RTA
kypokalemia and hypophosphatemic rickets
Etiology of Type 4 (hyperkalemic) RTA?
Hypoaldosteronism or collecting tubule insensitivity to aldo.