Carbon Dioxide Transport and pH Homeostasis

Question 1

What are the three major forms blood caries CO2 and what percent is each?

Answer 1

Dissolved CO2 - 5%
Bicarbonate - 90%
Carbamino compounds - 5%

Question 2

What is the buffer system in the blood? What does it reflect in the body?

Answer 2

carbonic acid/ bicarbonate. (Imidazole buff is also somewhat important) It reflects the pulmonary function of the organism giving it even greater diagnostic value.

Question 3

What does the Haldane effect do?

Answer 3

It minimizes acidification of the venous blood. Deoxyhemoglobin is a weaker acid than oxyhemoglobin. The Bohr effect is also explained by this fact.

Question 4

What is the Haldane effect?

Answer 4

At any given PCO2, total CO2 content increases as PO2 decreases.

Question 5

What is the Bohr effect?

Answer 5

At any given PO2, oxygen saturation decreases as PCO2 increases.

Question 6

What is the Henderson-Hasselbalch equation?

Answer 6

pH = pK + log [HCO3-/CO2]
[CO2] = 0.03 x PCO2 which is typically 40 in the lung and 46 in tissue.
pK = 6.1

Question 7

What does the kidney regulate? What about the lung?

Answer 7

Kidney regulates bicarbonate and the lung regulates PCO2; together they regulate blood pH.

Question 8

What does a compromised pulmonary function often lead to?

Answer 8

Acidosis. This was shown in different experiments where acid was added to a beaker with physiological concentration. The pH decreased for all of them except when the beaker was “ventilated” like the body would normally do. Buffering in an open system with ventilatory response maintains blood pH