How does gas exchange occur in the alveoli?

Answer 1

Gas is exchanged by diffusion.

We have followed the path of the air and of the oxygen into the bloodstream. But breathing is a two-way street: we breathe in and then we breathe out. When we breathe in, or inhale, oxygen is removed from the air. Breathing also removes waste from the lungs and from our noses and mouths. How does this waste material get into the air that we breathe out, or exhale?

The thin walls of the alveoli actually have two purposes. When we breathe in, oxygen passes through the walls of the alveoli and into the blood. Carbon dioxide and water vapor then travel the opposite direction. They are the main waste products that pass from the blood vessels (arteries) in the lungs, into the alveoli, through the windpipe and out the nose and mouth.

In the alveoli, oxygen crosses over into the blood stream and carbon dioxide leaves the blood stream and enters the alveoli to be expelled through the lungs.

Answer 2

Alveoli- these are the small sac-like structures where gas exchange occurs with the blood. Its creates an ideal site for gas exchange between the air in the lungs and the blood in the capillaries.

Answer 3

Gas exchange works by diffusion. The movement of molecules from a Higher concentration gradient to an area of lower concentration gradient.

Since there is more oxygen in the alveoli than in the capillaries, oxygen diffuses from the alveoli to the capillaries. And since there are more carbon dioxide in the capillaries than in the alveoli, carbon dioxide diffuses from the capillaries to the alveoli.

Answer 4

There are about 170,000,000 alveoli in your lungs. The total estimated surface area is about 1100 square feet. Gaseous exchange occurs through such a large surface area. You have a thin wall of capillary and thin wall of alveolus, that separates the blood and the air. So both come very close to each other, but do not get mixed up. The blood flows very slowly in the capillaries, but the length of capillaries is very less. Within few milliseconds the gaseous exchange takes place by way of diffusion. That is transferred from higher concentration to lower concentration. No energy is required in this process.

Answer 5

The capillaries are very close to the alveoli. Gases move across their boundary in response to the diffusion gradient.

Answer 6

Yep.