Where in the lungs does diffusion take place and what gasses are diffused?

Diffusion in the lungs takes place in the alveoli.

- The alveoli are small, sac-like structures in the lungs where gas exchange occurs.

- They are lined with capillaries, which are tiny blood vessels.

- The walls of the alveoli and capillaries are very thin, allowing for the efficient diffusion of gases.

During inhalation, fresh air enters the lungs and fills the alveoli. This air contains oxygen (O2) and other gases, such as nitrogen (N2) and carbon dioxide (CO2).

During exhalation, the stale air in the lungs is expelled, and it carries away waste gases, such as carbon dioxide (CO2). Diffusion occurs in the alveoli, allowing氧气(O2)to enter the bloodstream and碳 dioxide(CO2)to leave the bloodstream.

During inspiration, oxygen passes from the alveoli into the capillaries, while carbon dioxide diffuses in the opposite direction, from the capillaries into the alveoli.

The partial pressure of oxygen in the alveoli is higher than the partial pressure of oxygen in the capillaries, so oxygen moves from an area of higher concentration to an area of lower concentration, down its concentration gradient.

The partial pressure of carbon dioxide in the capillaries is higher than the partial pressure of carbon dioxide in the alveoli, so carbon dioxide moves from an area of higher concentration to an area of lower concentration, down its concentration gradient.

The overall effect of diffusion in the alveoli is the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. Oxygen is taken up by the bloodstream, while carbon dioxide is removed from the bloodstream.