What is the role of skin, lungs and intestine in the process of excretion in man?
1. Skin- Our skin contains sweat glands that excrete excess water, salts and nitrogenous waste through the skin pores. This cools our body when the sweat is evaporated from the skin, heat is absorbed from the skin cells.
2. Lungs- The alveoli increase in the surface area for the exchange of gases. The air in the alveoli has more oxygen than the air in the capillaries. The oxygen moves into the blood capillaries through the process of diffusion this oxygen is carried to every cell in the body by the blood. Blood also carries carbon dioxide to the lungs and it diffuses from the capillaries into the alveoli.
3. Intestine: The liver and intestines excrete bile pigments that result from the destruction of hemoglobinThe liver and intestines excrete bile pigments that result from the destruction of hemoglobin