Question

Describe (in order) the anatomical structures through which a molecule of oxygen moves from the time it enters your pharynx until the time it enters your blood.

Answer 1

The oxygen molecules move from the alveoli into the bloodstream, then into body cells through diffusion. Carbon dioxide moves in the opposite direction. This process takes place in the respiratory system.

Step-by-step explanation:

The anatomical structures through which a molecule of oxygen moves from the time it enters your pharynx until the time it enters your blood are as follows:

1. The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place. The transfer of oxygen into the blood is through simple diffusion.
2. The oxygen-rich blood returns to the heart.
3. The oxygen molecules move, by diffusion, out of the capillaries and into the body cells. Meanwhile, carbon dioxide moves from the cells into the capillaries.
4. Carbon dioxide is transported back to the heart and then to the lungs through the blood, where it is released into the air during exhalation.

This entire process is part of the respiratory system, which is responsible for exchanging gases between the lungs and the blood.