Question

internal and external respiration

Answer 1

External respiration is basically the transfer of gas between respiratory organs such as lungs and the outer environment. It takes place prior to internal respiration. Internal respiration is the transfer of gas between the blood and cells. External respiration also known as breathing refers to a process of inhaling oxygen from the air into the lungs and expelling carbon dioxide from the lungs to the air. Exchange of gases both in and out of the blood occurs simultaneously. External respiration is a physical process during which oxygen is taken up by capillaries of lung alveoli and carbon dioxide is released from blood.

Internal respiration or tissue respiration/cellular respiration refers to a metabolic process in which oxygen is released to tissues or living cells and carbon dioxide is absorbed by the blood. Once inside the cell the oxygen is used for producing energy in the form of ATP.

Answer 2

internal respiration. : the exchange of gases (as oxygen and carbon dioxide) between the cells of the body and the blood by way of the fluid bathing the cells — compare external respiration.

external respiration. : exchange of gases between the external environment and a distributing system of the animal body (as the lungs of higher vertebrates or the tracheal tubes of insects) or between the alveoli of the lungs and the blood — compare internal respiration.