Module 01: Fluid and Electrolyte Balance - Water and Blood Volume Balance

Which of the following statements does not describe the movement of water across the late distal tubule and collecting duct?

Water flows from the blood plasma to tubule lumen.

Angiotensin II leads to a change in kidney function by ________.

initiating the release of aldosterone and antidiuretic hormone (ADH)

When mean arterial pressure decreases, which of the following may increase in response?

ADH levels and water reabsorption

An osmotic gradient exists in the renal medulla because various parts of the loop of Henle differ from each other. Which of the following contribute to the osmotic gradient?

All of the listed responses are correct.

Plasma solute concentration directly or indirectly affects ________.

All of the listed responses are correct.

The plasma can gain or lose water and/or solutes by ________.

All of the listed responses are correct.

The signals controlling ADH release come from ________.

All of the listed responses are correct.

When mean arterial pressure increases, which of the following increase(s) in response?

GFR and urine volume

When insufficient water intake leads to dehydration, what compensatory mechanism preserves plasma volume and homeostatic osmolarity?

Increase the amount of water that is reabsorbed from the filtrate at the collecting duct.

Which of the following is not true of thirst?

Thirst is a physiological mechanism that maintains fluid and electrolyte balance.

Which of the following hormones acts directly on the collecting duct of the kidney to enhance the reabsorption of water?

antidiuretic hormone (ADH)

Hemorrhage would tend to increase the secretion of each of the following, except ________.

atrial natriuretic peptide

If a person drinks 200 mL of seawater, how does the body correct for the increase in plasma osmolarity?

by increasing the release of antidiuretic hormone (ADH)

Put the following events of the renin-angiotensin-aldosterone system in the correct order: a. Angiotensin I is converted to angiotensin II. b. Renin is secreted by the granular cells. c. Aldosterone is released from the adrenal glands. d. Renin converts angiotensinogen into angiotensin I. e. Cells in the macula densa detect a decrease in the flow of fluid (or ion concentration) in the distal tubule.

e, b, d, a, c

An ACE (angiotensin converting enzyme) inhibitor is used to treat ________.

hypertension since ACE inhibition results in decreased secretion of anti-diuretic hormone and aldosterone

If a person with a normal body fluid osmolarity drinks a large quantity of water, which of the following would occur if the kidneys could not excrete any of the water?

hypervolemia and decreased plasma osmolarity

The effects of angiotensin II on the central nervous system are to ________.

increase thirst, increase cardiac output, and cause peripheral vasoconstriction

The organ(s) that regulate water loss to maintain water balance is (are) the ________.

kidneys

When compared to filtrate entering the descending limb of the loop of Henle, filtrate leaving the ascending limb of the loop of Henle is ________ in volume and ________.

lower; hypo-osmotic

The primary function of the vasa recta is to ________.

maintain the medullary concentration gradient

People suffering from central diabetes insipidus (a disorder of the hypothalamus or pituitary gland) may have increased ________.

plasma osmolarity and urine volume

An antidiuretic hormone (ADH) receptor antagonist would ________.

prevent aquaporins from being inserted into the apical membranes of collecting duct cells

Angiotensin II leads to an alteration in kidney function by __________.

release of both aldosterone and ADH