RESPIRATORY SYSTEM
Respiration : Respiration is a process of uptake of oxygen and removal of carbon dioxide from tissues of the body. The cells in the body derive energy mainly by utilizing oxygen.carbon dioxide (CO2) is produced as a by-product.Carbon dioxide has to be eliminated from the cell. Unicellular Organisms exchange oxygen and CO2 directly with the external environment.Multicellular organisms require a specialized system to exchange O2 and CO2 with the external environment.This complex function is performed by the respiratory system. External respiration :Exhange of gases between the atmosphere and the lungs. Internal respiration ; Exchange of gases between blood and tissues. Respiration Involves two processes : 1.Inspiration:During this phase air is taken into the lungs from the atmosphere 2. Expiration:Dur...