What is the difference between external and internal respiration in terms of gas exchange and location?
External respiration is the exchange of oxygen and carbon dioxide between the alveolar air and the blood in the lungs, where oxygen moves from the alveoli into the blood and carbon dioxide moves from the blood into the alveoli. Internal respiration is the exchange of these gases between the blood and body tissues, where oxygen moves from the blood into the tissues and carbon dioxide moves from the tissues into the blood.