NEET PG DENTAL EXAM

Detailed explanation-1: -Ventilation is the process by which air moves in and out of the lungs. Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs.

Detailed explanation-2: -The rate of gas exchange is affected by: the area available for diffusion • the distance over which diffusion occurs • the concentration gradient across the gas exchange surface • the speed with which molecules diffuse through membranes.

Detailed explanation-3: -Adaptations of the alveoli: Thin walls-alveolar walls are one cell thick providing gases with a short diffusion distance.

Detailed explanation-4: -a) The alveoli wall (and the capillary wall) is only one cell thick so there is only a short distance over which diffusion takes place (short diffusion pathway) so there is a faster rate of diffusion of oxygen from alveoli into the blood.