Question 1

The activity of the respiratory system can increase pH by

Accepted Answer

Hyperventilation decreases PCO2, reducing carbonic acid and increasing blood pH (alkalosis).

Question 2

Under severe acidic conditions, the proximal tubules can convert into bicarbonate.

Accepted Answer

Under severe acidic conditions, the proximal tubules in the kidneys can metabolize glutamine to produce bicarbonate, which helps in maintaining acid-base balance.

Question 3

In the early portion of the collecting duct (in cortical interstitial fluid), an increase in water permeability will result in a(n)

Accepted Answer

An increase in water permeability in the collecting duct leads to more water being reabsorbed into the surrounding interstitial fluid, thus decreasing the volume of the filtrate remaining in the duct.

Question 4

Aldosterone increases the number of potassium channels where?

Accepted Answer

Aldosterone increases the number of potassium channels in the apical membrane of principal cells in the distal nephron, enhancing potassium secretion.

Question 5

A student in your physiology lab is thirsty and decides to sneak a drink of deionized or distilled water. The student drinks a fairly large quantity of this water in a short period of time. What will happen to the student's cells?

Accepted Answer

Drinking a large quantity of deionized or distilled water, which is hypotonic compared to the body's cells, will cause water to move into the cells by osmosis, leading to cell swelling.

Question 6

What solute maintains the medullary interstitial fluid osmotic gradient?

Accepted Answer

Urea is the major solute that maintains the medullary interstitial fluid osmotic gradient.

Question 7

Angiotensin II and atrial natriuretic peptide are able to alter the reabsorption of water through a similar pathway that involves altered

Accepted Answer

The answer of Angiotensin II and atrial natriuretic peptide are...

Question 8

The regulation of water and ion excretion occurs primarily within the

Accepted Answer

The regulation of water and ion excretion primarily occurs within both the collecting ducts and the late distal tubules. These areas of the nephron are key sites for the hormonal control of water and electrolyte balance, allowing the body to adjust urine concentration according to needs.

Question 9

How does severe vomiting cause a metabolic alkalosis?

Accepted Answer

Severe vomiting leads to the loss of gastric acid, which contains hydrogen ions (H+). This loss of hydrogen ions results in a decrease in acidity and an increase in blood pH, causing metabolic alkalosis.

Question 10

A patient is exhibiting several signs of acid- base imbalance. Blood tests reveal that blood pH is 7.5, and bicarbonate and carbon dioxide levels in blood are both low. What is the state of this patient?

Accepted Answer

The blood pH of 7.5 indicates alkalosis. Low bicarbonate and low carbon dioxide levels suggest respiratory alkalosis with renal compensation, as the kidneys attempt to retain bicarbonate to compensate for the loss of CO2.

Question 11

Which statement best describes why estrogen may contribute to osteoporosis?

Accepted Answer

A decrease in estrogen stimulates the production of interleukin-6, which in turn stimulates osteoclast activity, leading to increased bone resorption and contributing to osteoporosis.

Question 12

Angiotensin II acts directly in the hypothalamus to stimulate what?

Accepted Answer

Angiotensin II acts on the hypothalamus to stimulate thirst, which helps to increase fluid intake and subsequently blood volume and pressure.

Question 13

ADH increases the insertion of aquaporin- 2 where?

Accepted Answer

ADH (antidiuretic hormone) increases the insertion of aquaporin-2 water channels into the apical membrane of principal cells in the collecting ducts of the kidney, facilitating water reabsorption.

Question 14

The last step to synthesis of 1,25- dihydroxy vitamin D3 occurs in what organ?

Accepted Answer

The last step in the synthesis of 1,25-dihydroxy vitamin D3, also known as calcitriol, occurs in the kidney where 25-hydroxyvitamin D is hydroxylated to form the active form of vitamin D.

Question 15

Carbonic anhydrase is located where?

Accepted Answer

Carbonic anhydrase is located on the apical membrane of the proximal tubule.

Question 16

How might a high- fat diet cause metabolic acidosis?

Accepted Answer

A high-fat diet can lead to the breakdown of fat into fatty acids, which can increase the production of ketone bodies, leading to metabolic acidosis.

Question 17

Which of the following accurately describes the thick ascending limb of the loop of Henle?

Accepted Answer

The thick ascending limb of the loop of Henle is impermeable to water and contains Na+/K+/Cl- cotransporters, which actively reabsorb these ions from the filtrate.

Question 18

What form of osteoporosis would be localized to a specific bone?

Accepted Answer

Disuse osteoporosis occurs when a bone is not subjected to regular stress or use, leading to localized bone density loss. This can happen, for example, in a limb that is immobilized in a cast for a long period.

Question 19

What regulates the rate of water loss?

Accepted Answer

The kidneys regulate the rate of water loss by filtering blood and adjusting the concentration of urine, thus controlling the body's fluid balance.

Question 20

Which of the following ions acts as a buffer to minimize changes in intracellular pH?

Accepted Answer

Phosphate ions act as a buffer in the intracellular fluid, helping to maintain a stable pH by neutralizing excess acids or bases.

Quiz 19: The Urinary System: Fluid and Electrolyte Balance