what causes oxygen to enter the blood?where does this occur?
Answers
Answer:
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion. The oxygen-rich blood returns to the heart.
Answer:
Once you take in a breath of air, the oxygen doesn't just stay there in your lungs. It has a lot of traveling to do! Oxygen has to reach each one of your cells. How do you think the oxygen is moved?
The Journey of a Breath of Air
Breathing is only part of the process of bringing oxygen to where it is needed in the body. After oxygen enters the lungs, what happens?
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion.
The oxygen-rich blood returns to the heart.
Oxygen-rich blood is then pumped through the aorta, the large artery that receives blood directly from the heart.
From the aorta, oxygen-rich blood travels to the smaller arteries and, finally, to the capillaries, the smallest type of blood vessel.
The oxygen molecules move, by diffusion, out of the capillaries and into the body cells.
While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.
Carbon dioxide is brought, through the blood, back to the heart and then to the lungs. Then it is released into the air during exhalation.