NEET BIOLOGY

Detailed explanation-1: -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. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

Detailed explanation-2: -This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli. Here you see red blood cells traveling through the capillaries. The walls of the alveoli share a membrane with the capillaries. That’s how close they are.

Detailed explanation-3: -Gas exchange is the physical process by which gases move passively, meaning that no energy is required to power the transport, by diffusion across a surface.

Detailed explanation-4: -Gas exchange occurs by diffusion across cell membranes. Gas molecules naturally move down a concentration gradient from an area of higher concentration to an area of lower concentration. This is a passive process that requires no energy. To diffuse across cell membranes, gases must first be dissolved in a liquid.

Detailed explanation-5: -As stated, all gases exchange between alveolar gas and pulmonary capillary blood by passive diffusion.