Fluid and Electrolyte Balance Water and Blood Volume Balance

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

all answers are correct -exchange with extracellular connective tissue, such as bone -exchange with the lumen of the GI tract -respiration

The signals controlling ADH release come from __________.

all answers are correct -the macula densa -arterial baroreceptors -osmoreceptors in the hypothalamus

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

increasing water reabsorption from the collecting ducts and increasing sodium reabsorption along the distal tubules

Hemorrhage would tend to increase the secretion of which of the following?

ADH, aldosterone, and erythropoietin

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

ADH levels and water reabsorption

Plasma solute concentration directly or indirectly affects __________.

All answers are correct -changes in plasma volume -mean arterial pressure -the amount of water in the various body fluid compartments

If a human drinks 200 ml of seawater, how will the body correct for the increase in plasma osmolarity?

By increasing the release of vasopressin

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

GFR and urine volume

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

Moderate changes in blood pressure (mean arterial pressure not less than 80 mmHg or greater than 180 mmHg) generally do not affect the glomerular filtration rate due to which known local control processes within the kidney?

The myogenic response and tubule-glomerular feedback

Which of the following is not true of thirst?

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

In the absence of ADH, which of the following will decrease?

Urine osmolarity and aquaporin synthesis

An osmotic gradient develops in the renal medulla because various parts of the loop of Henle differ from each other in which of the following characteristics?

all answers are correct -active transport of solutes -permeability to water -direction of fluid movement

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

antidiuretic hormone

Put the following events 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 would be used to treat __________.

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

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

increase thirst, increase cardiac output, and cause peripheral vasoconstriction

When insufficient water intake leads to dehydration, compensatory mechanisms to preserve plasma volume and homeostatic osmolarity include __________.

increasing the amount of water that is reabsorbed from the filtrate in the collecting duct

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

kidneys

Filtrate leaving the loop of Henle is __________ in volume and __________ to the fluid entering the loop.

lower; hypo-osmotic

The primary function of the vasa recta is to __________.

maintain the medullary concentration gradient

The movement of water across the late distal tubule and collecting duct is __________.

passive, through channels called aquaporins, and driven by the medullary osmotic gradient

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

plasma osmolarity and urine volume

A vasopressin receptor antagonist would __________.

prevent membrane recycling in collecting duct cells

Angiotensin II stimulates the __________.

release of aldosterone and release of ADH