Anatomy & Physiology Chapter 20

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

ADH, aldosterone, and erythropoietin

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?

Active transport of solutes Direction of fluid movement Permeability to water

Suppose that your company is developing a new drug that blocks aldosterone synthesis. You would expect that patients given this drug in clinical tests would respond with ________

a higher concentration of sodium in their urine than in patients given a placebo

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

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

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

ADH levels and water reabsorption

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

Antidiuretic hormone

In which of the following locations is the osmolarity of the filtrate the greatest?

At the base of the loop of Henle

If plasma calcium levels decrease, which of the following may increase in response?

Bone resorption, PTH (parathyroid hormone) and reabsorption of calcium by the kidneys

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

Hormonal regulation of Na+ reabsorption occurs in which part of the nephron?

Distal convoluted tubule and collecting duct

Potassium is filtered, secreted and reabsorbed by the nephrons of the kidney. In what order does the majority of each process occur?

Filtration, reabsorption, secretion

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

GFR and urine volume

The excretion of which substances is primarily regulated in the late distal tubule and collecting duct?

H2O, H+ and Na+

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

Which of the following is appropriately linked to increased renin secretion?

Increased sodium reabsorption in the distal nephron

Acid-base balance in the distal tubule and collecting duct is regulated by what epithelial cell type?

Intercalated

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

Kidneys

Which of the following types of transporters found in the cells lining the collecting duct help to maintain acid-base balance by promoting H+ transport into the tubule lumen?

Na+/H+ countertransporter and H+ pump H+ pump Na+/K+ ATPase Na+/H+ countertransporter

Which of the following statements about the handling of potassium by the renal system is false?

Potassium leak channels are located on the apical membranes of the epithelial cells in the collecting duct.

Suppose that a comatose patient on a respirator has a pH of 7.5. Should the ventilation rate of the patient be increased or decreased, and why?

Ventilation rate should be decreased in order to increase plasma CO2.

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.

The active transport of which of the following contribute(s) to the medullary osmotic gradient?

Urea, chloride, and potassium

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

Urine osmolarity and aquaporin synthesis

High plasma PCO2 would not ________

be a result of hyperventilation

The release of renin is stimulated by a decrease in _____

blood volume, GFR and sodium and chloride concentration in the distal tubule

Metabolic acidosis is a decrease in plasma pH due to failure of body systems to compensate for H+ ions acquired from metabolic processes or the diet or from a loss of bicarbonate ions, as from diarrhea. Compensatory mechanisms work to prevent a change in plasma pH or to bring it back to homeostasis if it decreases. Put the following compensatory mechanisms in order of fastest to slowest response: a) changes in ventilation rate b) renal transport of H+ and HCO3- c) buffering by HCO3- or HPO42

c, a, b

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

The plasma can gain or lose water and/or solutes by _____

exchange with the lumen of the GI tract exchange with extracellular connective tissue, such as bone respiration

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

High ECF K+ stimulates ______

increased synthesis and secretion of aldosterone

Organs involved in calcium balance include __________

kidneys skin gastrointestinal tract bones

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

lower; hypo-osmotic

Arterial blood pH is regulated by the ______

lungs and kidneys

The primary function of the vasa recta is to _____

maintain the medullary concentration gradient

The signals controlling ADH release come from ______

osmoreceptors in the hypothalamus arterial baroreceptors the macula densa

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

Atrial natriuretic peptide (ANP) decreases _________

secretion of aldosterone reabsorption of sodium secretion of renin

Metabolic acidosis can be caused by _____

severe diarrhea and a diet high in protein and fat

If someone eats a large quantity of salty potato chips, to maintain homeostasis the kidneys may excrete urine that is higher in ________

solute concentration and osmolarity

Plasma solute concentration directly or indirectly affects __________.

the amount of water in the various body fluid compartments changes in plasma volume mean arterial pressure