Question

During the process of gaseous exchange in the alveoli, what kind of movement of gases can be observed?

• A. Oxygen is inhaled and directly passed to the blood for the exchange
• B. Carbon dioxide diffuses in and oxygen diffuses out.
• C. Carbon dioxide diffuses out and oxygen diffuses in.
• D. None of the above.

Answer 1

The correct option is C Carbon dioxide diffuses out and oxygen diffuses in.

The process of inhalation includes the entry of oxygen from the external environment into the lungs. Oxygen reaches the alveoli (having a single-layered squamous epithelial layer), where it is diffused into the blood (for the process of cellular respiration in the mitochondria of a cell). Carbon dioxide (a byproduct of cellular respiration process) is released by the cell and reaches the lungs through the body's circulation. It gets exchanged through the single-layered squamous epithelial layer of alveoli by using the process of diffusion and then finally, it is exhaled.