The purpose of surfactant in the lungs is to
A. facilitate lung expansion.
B. bind oxygen from the air.
C. improve lung blood flow.
D. remove pollutants in the air.
I believe it's A
To determine the purpose of surfactant in the lungs, let's understand what surfactant is. Surfactant is a substance that is produced by special cells called type II alveolar cells in the lungs. It is composed of lipids and proteins.
Surfactant serves an important role in lung functioning. Its main purpose is to reduce surface tension within the alveoli, which are small air sacs in the lungs where gas exchange occurs. The surface tension is the force that causes liquid molecules to stick together. In the case of the lungs, this force would cause the alveoli to collapse and resist expansion.
Therefore, the correct answer is A) facilitate lung expansion. Surfactant helps to lower the surface tension, allowing the alveoli to remain open and expand easily with each breath. This is essential for efficient gas exchange and normal lung function.