Difference between external respiration and internal respiration.
The correct answer and explanation is:
Correct Answer:
External respiration refers to the exchange of gases between the lungs and the atmosphere, specifically oxygen intake and carbon dioxide expulsion. On the other hand, internal respiration involves the exchange of gases between the blood and tissues, where oxygen is delivered to cells, and carbon dioxide is removed.
Explanation:
External respiration occurs in the lungs, where oxygen from the atmosphere is inhaled through the respiratory system and diffuses into the bloodstream, while carbon dioxide, produced by cellular respiration, diffuses out of the blood and is exhaled. The process is essential for maintaining the oxygen supply for the body while eliminating excess carbon dioxide. This process mainly involves the alveoli, tiny air sacs in the lungs, where gas exchange occurs. Oxygen diffuses from the alveoli into the blood in the pulmonary capillaries, and carbon dioxide moves in the opposite direction, from the blood into the alveoli to be expelled from the body through exhalation.
In contrast, internal respiration happens at the cellular level. It is the process by which oxygen is transported by the blood to tissues and organs, where it is used for cellular metabolism. As cells use oxygen to produce energy (ATP) through cellular respiration, they release carbon dioxide as a waste product. This carbon dioxide diffuses from the cells into the bloodstream and is carried back to the lungs for elimination. The exchange of gases in the tissues is facilitated by capillaries, where oxygen from the blood diffuses into the cells, and carbon dioxide from the cells moves into the blood.
Both processes are crucial for maintaining life, as oxygen is needed for cellular activities, and the removal of carbon dioxide is necessary to prevent toxic accumulation in the body. External respiration ensures oxygen reaches the blood, and internal respiration ensures that oxygen reaches the cells where it is most needed.