An area of the lung has no ventilation but is normally perfused by the pulmonary circulation. Which of the following statements are correct?
I .Blood exiting the pulmonary capillary will have a PO₂ = 40 and a PCO₂ = 46.
II.The area represents an alveolar shunt.
III.The $\dot { V }$ / $\dot { Q }$ is 0.

Question

An area of the lung has no ventilation but is normally perfused by the pulmonary circulation. Which of the following statements are correct?
I .Blood exiting the pulmonary capillary will have a PO₂ = 40 and a PCO₂ = 46.
II.The area represents an alveolar shunt.
III.The

\dot { V }

/

\dot { Q }

is 0.

Quizplus · Accepted Answer

The area with no ventilation but normal perfusion is an example of an alveolar shunt, where blood bypasses the alveoli without gas exchange, leading to a ventilation/perfusion ($\dot { V }$/$\dot { Q }$) ratio of 0. Blood exiting the pulmonary capillary in this scenario will maintain systemic arterial values for oxygen and carbon dioxide, typically a PO2 of 40 mmHg and a PCO2 of 46 mmHg, as there is no gas exchange to alter these values.

An Area of the Lung Has No Ventilation but Is V˙\dot { V }V˙

An Area of the Lung Has No Ventilation but Is $\dot { V }$