Physiology - from Ganong's 23rd ed Chapter 40 - Acidification of the Urine

Question 1

Which of the following is the principal buffer in interstitial fluid?

A) Hemoglobin

B) Other proteins

C) Carbonic acid

D) H₂PO₄

E) compounds containing histidine

Answer 1

C

Question 2

Increasing alveolar ventilation increases the blood pH because

A) it activates neural mechanisms that remove acid from the blood

B) it makes hemoglobin a stronger acid

C) it increases the P_O2 of the blood

D) it decreases the P_CO2 of the blood

E) the increased muscle work of increased breathing generates more CO₂

Answer 2

D

Question 3

In uncompensated metabolic alkalosis

A) The plasma pH, the plasma HCO₃^- concentration, and the arterial P_CO2 are all low.

B) the plasma pH is high and the plasma HCO₃^- concentration and arterial P_CO2 are low.

C) the plasma pH and the plasma HCO₃^- concentration are low and the arterial P_CO2 is normal.

D) the plasma pH and the plasma HCO₃^- concentration are high and the arterial P_CO2 is normal.

E) the plasma pH is low, the plasma HCO₃^- concentration is high, and the arterial P_CO2 is normal.

Answer 3

D

Question 4

In a patient with a plasma pH of 7.10, the [HCO₃^-]/[H₂CO₃] ratio in plasma is

A) 20

B) 10

C) 2

D) 1

E) 0.1

Answer 4

B. Remember that the pK’ of the bicarbonate system is 6.1, which means that at a pH of 6.1, the H₂CO₃ will be 50% dissociated.