Regulation of Extracellular Sodium & Water

Question 1

A decrease in MAP activates ______.

Answer 1

the renin/angiotensin axis

Question 2

______ ==> shift of ECF water into cells ==> decreased ECF volume ==> decreased MAP ==> increased baroreceptor reflexes (arterial and intrarenal) ==> increased renin ==> increased AgII ==> increased aldosterone ==> increased Na reabsorption in distal tubule and collecting duct ==> addition of ingested Na to ECF

Answer 2

Loss of ECF Na

Question 3

In a function apart from its vasoconstrictive role, _____ acts on cells of the adrenal cortex and causes them to increase aldosterone synthesis.

Answer 3

AgII

Question 3

_____ is a peptide hormone that is synthesized in neurons located in the hypothalamus of the brain.

Answer 3

ADH

Question 3

Increased ECF osmolarity causes activation of?

Answer 3

hypothalamic osmoreceptors

Question 4

The normal Na+ concentration in the ECF is considered to be in the range of _______.

Answer 4

135-145mM

Question 4

ADH is a peptide hormone that is synthesized in the _______.

Answer 4

hypothalamus of the brain

Question 5

Losses or gains in ECF sodium cause greater changes in _____ than they do in _____.

Answer 5

ECF volume>Na concentration

Question 6

The sensors of sodium regulation monitor changes to ______.

Answer 6

ECF volume (not Na concentration!)

Question 7

ADH release from the post pituitary causes?

Answer 7

increased water reabsorption in the distal t. and collecting duct

Question 8

How does severe sweating change the osmolarity of the ECF?

Answer 8

it becomes hypertonic

Question 9

Loss of ECF Na ==> _______ ==> decreased ECF volume ==> decreased MAP ==> increased baroreceptor reflexes (arterial and intrarenal) ==> increased renin ==> increased AgII ==> increased aldosterone ==> increased Na reabsorption in distal tubule and collecting duct ==> addition of ingested Na to ECF

Answer 9

shift of ECF water into cells

Question 10

Diarrhea represents an ______ loss of ECF via pathological secretion into the gut.

Answer 10

isotonic

Question 11

Changes in ECF volume have little effect on _____ levels, except when ECF volume falls severely.

Answer 11

ADH

Question 12

What is ANP?

Answer 12

a potent diuretic peptide that also increases sodium excretion

Question 14

Due to the two-fold greater volume of the cellular over the ECF compartment, gains (or losses) of sodium from the ECF result in _____-fold greater changes in ECF volume than they do in ECF sodium concentration.

Answer 14

two

Question 15

Where are the baroreceptors in the heart located?

Answer 15

in the auricle (a.k.a. “left atrial appendage”)

Question 17

What hormone dilates both the afferent and efferent arteriole?

Answer 17

ANP

Question 18

Where is ADH stored and released from?

Answer 18

the posterior pituitary

Question 20

Loss of ECF Na ==> shift of ECF water into cells ==> decreased ECF volume ==> decreased MAP ==> increased baroreceptor reflexes (arterial and intrarenal) ==> increased renin ==> increased AgII ==> increased aldosterone ==> _______ ==> addition of ingested Na to ECF

Answer 20

increased Na reabsorption in distal tubule and collecting duct

Question 21

This is a potent diuretic peptide that also increases sodium excretion.

Answer 21

ANP

Question 22

ANP acts to increase filtration by selectively dilating?

Answer 22

both the afferent and efferent arteriole

Question 23

The reduction in ECF volume in severe sweating is monitored by changes in blood pressure, which to a lesser extent is done by the ______.

Answer 23

arterial high pressure baroreceptors

Question 24

A decrease in ______ activates the renin/angiotensin axis.

Answer 24

MAP

Question 25

In a function apart from its vasoconstrictive role, AgII acts on cells of the adrenal cortex and causes them to increase ______ synthesis.

Answer 25

aldosterone

Question 26

Decreased ICF volume causes decreased LA pressure, which activates a baroreceptor reflex to the _____.

Answer 26

hypothalamus