Diffusion

Definition

Diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration. It plays a crucial role in the exchange of gases in the lungs and the distribution of nutrients in cells.

5 Must Know Facts For Your Next Test

1. Molecular diffusion is essential for oxygen and carbon dioxide exchange in the alveoli.
2. Nutrient diffusion affects cellular respiration by ensuring cells receive adequate glucose and oxygen.
3. In patients with pulmonary diseases, impaired diffusion can lead to decreased oxygen levels and compromised nutrition.
4. The rate of diffusion can be influenced by factors such as temperature, molecule size, and concentration gradients.
5. Proper hydration is vital as it facilitates optimal diffusion processes within bodily fluids.

Review Questions

• What role does diffusion play in gas exchange within the lungs?
• How can impaired diffusion affect a patient's nutritional status and pulmonary function?
• What factors influence the rate of molecular diffusion in the human body?

Related terms

Osmosis:

The movement of water molecules through a semi-permeable membrane from an area of low solute concentration to high solute concentration.

Partial Pressure: The pressure exerted by a single type of gas in a mixture of gases, important for understanding gas exchange.

Alveoli:

Tiny air sacs in the lungs where gas exchange occurs between the air and blood.