An Exchange Surface in Direct Contact with the External Environment

Question

An exchange surface in direct contact with the external environment is found in the
A)lungs.
B)skeletal muscles.
C)liver.
D)heart.
E)brain.

Accepted Answer

The lungs have alveoli, which are small air sacs that directly contact the external environment and allow for gas exchange between oxygen in the air and carbon dioxide in the blood. The other options listed do not have direct contact with the external environment for gas exchange.