Author Question: Which organ system maintains the normal level of HCO3 at 24 mEq/L? a. Liver b. Lung c. Renal ... (Read 56 times)

ENagel · **on:** Jul 16, 2018

Which organ system maintains the normal level of HCO3 at 24 mEq/L?

a. Liver
b. Lung
c. Renal
d. Spleen

Question 2

Which of the following is/are true about the relationship between chloride (Cl) and bicarbonate HCO3 in acid-base balance?

1. For each Cl ion excreted into the urine, the blood gains an HCO3 ion.
2. Blood Cl and HCO3 ion levels are reciprocally related.
3. People with chronically high CO2 tend to have low blood Cl levels.
4. Activation of the NH3 buffer system enhances Cl gain and HCO3 loss.
a. 2 and 3 only
b. 1, 2, and 3 only
c. 2 only
d. 2, 3, and 4 only

Jsherida · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: C
Normally, the kidneys maintain an arterial bicarbonate concentration of approximately 24 mEq/L, whereas lung ventilation maintains an arterial PCO2 of approximately 40 mm Hg.

Answer to Question 2

ANS: B
The net effect of ammonia buffer activity is to cause more bicarbonate to be reabsorbed into the blood, counteracting the acidic state of the blood. Figure 14-5 shows that when a Cl ion is ex-creted in combination with an ammonium ion, the blood gains an HCO3 ion. Thus, blood Cl and HCO3 ion concentrations are reciprocally related (i.e., when one is high, the other is low). This explains why people with chronically high blood PCO2 tend to have low blood Cl concentra-tions. Activation of the ammonia buffer system enhances Cl loss and HCO3 gain.