Question

why is breathing also called external respiration?​

Answer 1

Answer:

Gas exchange in the lungs is referred to as external respiration as one side of the respiratory membrane - that is, the alveolar air - is actually outside of the body. As blood flows through the pulmonary capillaries, oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar gas.

Answer 2

Answer:

Gas exchange in the lungs is referred to as external respiration as one side of the respiratory membrane - that is, the alveolar air - is actually outside of the body. As blood flows through the pulmonary capillaries, oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar gas.