Ch. 19 Review Questions

The kidneys also function in in acid-base balance by controlling which of the following ions?

H+ and HCO3–

If hydrogen ions are taken out of a solution, the pH will

Increase

Fluid and electrolyte balance occur when

Solutes and water enter and exit the plasma at the same rate

A substance is in negative balance when

It exits plasma at a greater rate than it enters plasma

A greater plasma volume than normal is called

Hypervolemia

A substance is in positive balance when

It enters plasma at a greater rate than it exits plasma

Bicarbonate crosses the apical membrane of the renal tubule by

Conversion to carbon dioxide

Kidneys compensate for changes in plasma volume and osmolarity by adjusting the rate of water reabsorption only.

False

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

Glutamine

Aldosterone is released from the ________ in response to ________.

Adrenal cortex; increases in plasma potassium

Which of the following is associated with actions of aldosterone on tubular cells?

Increased potassium secretion

Hyperkalemia refers to an excess of what?

K potassium

Potassium secretion is regulated by

Aldosterone

How might a high-fat diet cause metabolic acidosis?

Breakdown of fat into fatty acids

The role of a buffer is to

Limit the change in pH with changing hydrogen ion concentrations

What solute is primarily responsible for producing the osmotic gradient that drives water reabsorption?

Sodium

If hydrogen ions are added to a solution, the pH will

Decrease

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

Phosphate

What is the secondary defense against changes in pH that requires minutes to be activated?

Respiratory compensation

The most important buffer system in the extracellular fluid is

Bicarbonate

How might heavy exercise cause metabolic acidosis?

Production of lactic acid

The hydrogen ion concentration or pH of arterial blood is regulated by the combined actions of the ________ and ________.

Lungs; kidneys

Which of the following is NOT a metabolic disturbance that can result in a metabolic acidosis?

Excessive vomiting

When an increase in hydrogen ions remains after one hour, this will lead to a(n)

Increase in hydrogen ion secretion from the kidneys

Metabolic acidosis is a disturbance in blood pH caused by something other than an abnormal PCO2.

True

As the body becomes dehydrated, the osmolarity of the body fluids decreases.

False

What is the most rapid defense against changes in blood pH?

Buffering of hydrogen ions

Alterations in acid-base balance that originate from the respiratory system involve alterations in CO2 content within the blood.

True

How does severe diarrhea cause a metabolic acidosis?

Loss of bicarbonate

How does severe vomiting cause a metabolic alkalosis?

Loss of hydrogen ions

Acidosis results in potassium retention, whereas alkalosis results in potassium depletion.

True

A metabolic alkalosis will cause a decrease in ventilation and an increased excretion of bicarbonate.

False

Under normal conditions, the total solute concentration of the plasma and the interstitial fluid is approximately 300 mOsm.

True

In a state of negative balance, the quantity of a substance in the plasma tends to increase.

False

Antidiuretic hormone binds to receptors on cells in the collecting ducts and distal tubules where it ________.

Causes vesicles with aquaporin-2 to insert into the apical membrane

In order to compensate for a hyperventilation, the

Kidneys decrease the reabsorption of bicarbonate

Consumption of salty foods without drinking water will increase plasma osmolarity and cause cells to shrink.

True

A patient is exhibiting several signs of acid-base imbalance. Blood tests reveal that blood pH is 7.3, and bicarbonate and carbon dioxide levels in blood are both low. What is the state of this patient?

Metabolic acidosis with respiratory compensation

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?

Respiratory alkalosis with renal compensation

What would the following blood values indicate? Blood pH = 7.3, PCO2 is high, [HCO3-] is high.

Respiratory acidosis with renal compensation