Differentiate internal respiration from external respiration. Explain each of them by using illustrations.
The correct answer and explanation is:
Internal Respiration and External Respiration are two distinct processes involved in the movement of gases in the body.
External Respiration refers to the exchange of gases (oxygen and carbon dioxide) between the atmosphere and the blood. This process occurs in the lungs. Oxygen from the air enters the alveoli (tiny air sacs in the lungs), and from there, it diffuses into the capillaries. At the same time, carbon dioxide, which is a waste product from cellular respiration, moves from the blood into the alveoli to be exhaled out of the body.
Illustration for External Respiration:
- Oxygen enters the lungs from the atmosphere.
- Oxygen diffuses across the alveolar membrane into the capillaries.
- Carbon dioxide diffuses from the blood into the alveoli to be expelled.
Internal Respiration happens at the cellular level, where oxygen from the blood is transferred into the tissues, and carbon dioxide, a waste product of metabolism, is transferred from the tissues into the blood. The oxygen-rich blood travels through the arteries and capillaries, delivering oxygen to the body’s cells. In turn, the cells release carbon dioxide into the blood, which is then transported back to the lungs for removal.
Illustration for Internal Respiration:
- Oxygen-rich blood reaches the tissues.
- Oxygen diffuses from the blood into the tissues for cellular use.
- Carbon dioxide diffuses from the tissues into the blood to be transported back to the lungs.
In Summary:
- External respiration involves the exchange of gases between the lungs and the bloodstream.
- Internal respiration involves the exchange of gases between the blood and the body’s cells.
These two processes ensure that oxygen is delivered to tissues and that carbon dioxide, a byproduct of metabolism, is removed from the body.