Pulm/Renal - Physiology - Renal Hormones; Hypertension; Acid-Base Balance Flashcards
What is the major mediator of the effects of the renin-angiotensin system?
Angiotensin II
Besides the pulmonary circulation, where is another location where ACE is located?
The basolateral surface of renal cells
True/False.
Most angiotensinogen is produced by the PCT, but some is also produced in the liver.
False.
Most angiotensinogen is produced by the liver, but some is also produced in the PCT.
Angiotensin II primarily acts on ___ receptors.
AT2 receptors are primarily involved in:
AT1;
renal development
True/False.
A fraction of bodily angiotensin II can be produced completely within the kidney without any hepatic or pulmonary or circulatory involvement.
True.
Some angiotensinogen is produced in the renal interstitium, and ACE can be found on the basolateral epithelial surface.
What cell type produces renin?
Juxtaglomerular cells
What is the rate-limiting factor of the renin-angiotensin system?
Renin production
A.
B.
C.
Name the four major activating mechanisms for renin secretion.
(First row)
Name the three mechanisms for increasing renin secretion.
(Second row)
What happens in the juxtaglomerular cells for renin to be secreted?
(Third row)
A.
B.
C.
D.
C.
C.
True/False.
Angiotensin II has many diverse actions.
True.
What renal mechanism senses increased renal arteriolar stretch?
What is the result?
Baroreceptors in juxtaglomerulus (calcium channels opened);
inhibition of renin release
What effect does increased sympathetic tone have on juxtaglomerular cells?
β1 activation –> cAMP –> increased renin secretion
What effect does an increase in NaCl delivery to the macula densa have on the juxtaglomerular cells?
Why?
Decreased renin secretion;
the JG cells interpret this as increased ECF
(maybe mediated via PGE2)
A.
B.
C.
What effect does a decrease in NaCl delivery to the macula densa have on the juxtaglomerular cells?
Why?
Increased renin secretion;
the JG cells interpret this as decreased ECF
(maybe mediated via PGE2)
Name the major functions of angiotensin II in the following systems: renal, adrenal, blood vessels, heart, intestines, CNS, PNS.
- Renal: Reduce RBF, increase NaCl reabsorption
- Adrenal: Aldosterone release
- BV: Vasoconstriction
- Heart: Cardiac contractility
- Intestine: NaCl + H2O reabsorption
- CNS: Thirst, salt appetite, ADH release
- PNS: Sympathetic activity
What effect (if any) does angiotensin II have on the renal arterioles?
What effect (if any) does angiotensin II have on the Kf?
Efferent arteriole constriction (with no change in GFR);
it decreases it (mesangial contraction)
What parts of the nephron are stimulated to reabsorb NaCl by angiotensin II?
The PCT and DCT
What overall effect does angiotensin II have on the GFR?
How?
It maintains it;
efferent arteriole constriction
True/False.
Increases in Na+ retention via aldosterone will also result in an increase in K+ loss.
True.
A.
C.