Oxygen diffuses from the alveoli into surrounding capillaries.Oxygen diffuses from the alveoli into surrounding capillaries. Oxy
gen is carried through blood vessels to a capillary.Oxygen is carried through blood vessels to a capillary. Oxygen diffuses from the blood to the body's tissues.Oxygen diffuses from the blood to the body's tissues. Oxygen binds to a molecule of hemoglobin.Oxygen binds to a molecule of hemoglobin. Oxygen enters a red blood cell.Oxygen enters a red blood cell.
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. ... While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.