Skip to Main Content

++

Regulation of Sodium and Water Excretion

++
++
++

Which of the following cell types are not nerve cells?

++
++
++

a. Pituitary cells that secrete ADH

++
++

b. Baroreceptors located in pulmonary vessels

++
++

c. Baroreceptors located in the arch of the aorta

++
++

d. Intrarenal baroreceptors

+
++

(d) Intrarenal baroreceptors are modified smooth muscle cells in the afferent arteriole.

++
++
++

In the production of aldosterone, the rate-limiting step is

++
++
++

a. the production of angiotensin I.

++
++

b. the production of angiotensinogen.

++
++

c. the activity of angiotensin converting enzyme.

++
++

d. the responsiveness of the adrenal gland to angiotensin II.

+
++

(a) The action of renin to produce angiotensin I is the rate-limiting step because (1) there is excess substrate (angiotensinogen) and (2) almost all angiotensin I is converted to angiotensin II by angiontensin converting enzyme (ACE).

++
++
++

A person eats a large bag of very salty potato chips with no beverage. Which response is most likely to ensue?

++
++
++

a. Movement of aquaporins into the membranes of cortical collecting duct principal cells.

++
++

b. Enhanced activity of Na–H antiporters in the proximal tubule.

++
++

c. Enhanced activity of Na-K-ATPase pumps in collecting duct principal cells.

++
++

d. Decreased levels of natriuretic peptides in the blood.

+
++

(a) Consumption of salt without water concentrates the ECF and triggers secretion of ADH. A key action of ADH is to cause insertion of aquaporins into the luminal membrane of cortical collecting duct principal cells.

++
++
++

In response to a major hemorrhage

++
++
++

a. GFR increases.

++
++

b. ADH secretion is reduced.

++
++

c. Granular (juxtaglomerular) cells are stimulated by neural input.

++
++

d. Neural baroreceptor firing rate increases.

+
++

(c) Loss of blood volume and likely ensuing drop of arterial pressure both reduce the inhibition of sympathetic outflow (ie, sympathetic outflow increases). A prime target of sympathetic outflow in the kidneys is the juxtaglomerular cells.

++
++
++

The macula densa generates signals that directly regulate

++
++
++

a. GFR.

++
++

b. Sympathetic neural activity.

++
++...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.