EFC Control I (lec 13) Flashcards
Na+ regulation driven primarily by Δs in what?
Primary effector is?
Blood volume, mainly BP Δs
RAAS
H2O regulation driven primarily by Δs in what?
Primary effector is?
osmolarity and vol of ECF
ADH
Aldosterone release stimulated by?
↑ [AngII] or plamsa [K+] stims adrenal cortex ->
stims aldosterone realease
Aldosterone affects NaCl reabsorption how?
Stimulates Principle Cells in Late DCT and CD ->
Na+ reab, K+ secreted
Accounts for only 2% of Na+ filtration
Angiotensin II fxns are? (3)
1) vasoconstriction
2) aldosterone release
3) Na+/H+ exchange in PCT
Angiotensin II fxns all favor what? (2)
Na+ retention and ↑ arterial BP
Ang II controlled by?
Renin
Renin released by?
JGA
Intrarenal baroreceptors (granular cells) affect Renin release how?
JGA responds to stretch in afferent arterioles
Renin release is INVERSELY proportional to aff art pressure
Macula Densa affects Renin release how?
responds to flow DCT (GFR)
Renin release is INVERSELY proportional to GFR
Renal SNS affects Renin release how?
stim of SNS near granular cells ->
stim β-receptors ->
release renin
Atrial Natriuretic Peptide (ANP) release from?
In response to?
atria
response to high pressure
ANP affects GFR how?
dilates aff arterioles, constricts eff arterioles ->
↑ GFR, ↑ NaCl filtered load
ANP affects NaCl reab how?
Directly inhibits reab at CD by:
directly inhibiting renin/aldosterone secretion,
directly inhibiting Na+ reuptake by medulla CD
ADH released from?
In response to?
pituitary
high plasma Osmo or
low plasma volume (hypovolemia)
ADH affects H2O reab how? (3)
↑ aquaporins in CD basomemb,
↑ Na+/K+/2Cl-cotrans in LOH,
↑ CD permeability to urea
primary regulator of H2O balance
little effect on NaCl excretion
ADH control: Baroreceptors?
respond to low plasma vol ->
↑ ADH ->
↑ H2O reab
ADH control: Osmoreceptors?
respond to excess H2O ->
↓ ADH ->
↓ H2O reab
Osmolar Clearance (Cosm) is?
rate of blood plasma cleared of osmotically active particles (ml/min)
Cosm = UosmV/Posm
Normal Cosm = ?
1 to 2 ml/min
Gaining osmoles (+ osmo balance) results in?
Progresses towards?
low Cosm
edema
Low Cosm caused by?
↓ GFR, ↑ aldosterone, or dz that ↓ kidney ability to eliminate solute
Dumping of osmoles results in?
loss of ECF ->
high Cosm
High Cosm caused by?
diuretics, low aldosterone, or dz that ↓ kidney ability to reabsorb
