Summary summarized basics of gaseous exchange

Gaseous exchange
- physical process by which gases move by diffusion across a surface

Diffusion : the movement of a substance from an area of high concentration to an ares of lower
concentration until equilibrium is reached




Solute


The alveoli are adapted to make gaseous exchange in the lungs happen easily


Where does gaseous exchange occur :

- large surface are : mainly alvedi
- Thin walls : one cell layer thick , providing gasses with a short
diffusion distance
- Moist walls - gasses dissolve in moisture
- Permeable walls , easy to pass through
- Extensive blood supply , capillaries



Lungs :

- inhalation , higher concentration of oxygen in alveoli
- lower concentration of oxygen in blood capillaries surrounding
alveoli
= oxygen diffuses into blood capillaries
- Due to cellular respiration , there is a higher concentration of
carbon dioxide in capillaries
- lower concentration of carbon dioxide in alveoli
= carbon dioxide diffuses into alveoli to be exhaled