Question

required information
which of the following is true at the venous ends of the pulmonary capillaries?
multiple choice
the pco2 is higher in the capillaries than in the alveoli.
the pco2 is lower in the capillaries than in the alveoli.
the pco2 is equal in the capillaries and in the alveoli.
the pco2 is higher at first in the capillaries than in the alveoli, and then it is lower in the alveoli than in the capillaries.
the pco2 is lower at first in the capillaries than in the alveoli, and then it is higher in the alveoli than in the capillaries.

Explanation:

Gas exchange occurs in the lungs. Carbon dioxide (\(P_{CO_2}\)) diffuses from an area of higher concentration to an area of lower concentration. At the venous ends of the pulmonary capillaries, after gas exchange has occurred, the \(P_{CO_2}\) in the capillaries and alveoli reaches equilibrium.

Answer:

The \(P_{CO_2}\) is equal in the capillaries and in the alveoli.