Chapter 4.5 Breathing and gas exchange

Question 1

How is air moved in and out of your lungs?

Answer 1

When you exhale your diaphragm relaxes and moves upward into the chest cavity. As the space in the chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out of your nose or mouth.

Question 2

define the term gaseous exchange.

Answer 2

The diffusion of gases from an area of higher concentration to an area of lower concentration, especially the exchange of oxygen and carbon dioxide between an organism and its environment.

Question 3

How are alveoli adapted for their function?

Answer 3

Alveoli are folded to increase their surface area to volume ratio, so more volume of air can diffuse in from the blood and and in from the bronchioles. The lining of the alveoli walls are also moist so the gases can easily dissolve. The walls are thin so the diffusion distance is short.