Chapter 20 MAP

Which is a similarity between vasopressin and aldosterone?

Both increase transporters in the membranes of nephron epithelial cells.

At a campus event, you ate a lot of salty treats. Why would osmoreceptors in the hypothalamus shrink, and what would you predict for vasopressin release?

High plasma osmolarity, increased vasopressin release

What is the site and mechanism of the early response phase of aldosterone action?

Increased Na+/K+-ATPase activity in P cells of the distal nephron epithelium

If a patient had damage to his posterior pituitary that resulted in decreased secretion of vasopressin, which of the following would you expect?

Increased urine output and decreased blood volume

Why is a high medullary interstitial osmolarity important to renal function?

It allows reabsorption of water.

Which of the following has a direct effect to signal for renin secretion?

Low blood pressure

Dehydration leads to __________ blood volume, __________ blood pressure, and __________ osmolarity.

decreased; decreased; increased

The __________ limb of the loop of Henle is permeable only to __________, which are reabsorbed all along the length because the fluid outside is __________ concentrated deeper in the medulla.

descending; water molecules; more

Most cell types are permeable to water. An exception is cells of the __________, which can be either impermeable or permeable, depending upon the location of __________.

distal nephron; aquaporins

The ion imbalance known as __________ initially leads to __________ in excitable cells.

hyperkalemia; depolarization

Aldosterone secretion increases in response to __________ and causes __________.

increased angiotensin II; sodium reabsorption

Maintaining osmolarity is important to the body because the membranes of most cell types are freely permeable to ____.

water