EVERYDAY SCIENCE

Detailed explanation-1: -In addition to forming the connection between the arteries and veins, capillaries have a vital role in the exchange of gases, nutrients, and metabolic waste products between the blood and the tissue cells. Substances pass through the capillary wall by diffusion, filtration, and osmosis.

Detailed explanation-2: -Capillary Exchange Mechanisms Diffusion, the most widely-used mechanism, allows the flow of small molecules across capillaries such as glucose and oxygen from the blood into the tissues and carbon dioxide from the tissue into the blood.

Detailed explanation-3: -Small, lipid-soluble molecules, such as oxygen and carbon dioxide are able to freely diffuse across the membrane. However, molecules can also be exchanged via specialised channels or pores. The number of these channels or pores can vary depending on the function of the tissue.

Detailed explanation-4: -When we breathe in, the millions of air sacs in the lungs fill with fresh oxygenated air. The oxygen then moves into the blood by passing first through the very thin walls of the air sacs and then into the capillaries, which are tiny blood vessels in a network within the lungs.