I know that your blood carries oxygen to distribute to cells, but if the red blood cells and hemoglobin never leave the blood cells, how do the body cells receive oxygen from these cells? How is oxygen transferred?
In: Biology
The oxygen is carried bound up in the molecules of hemoglobin that are in your red blood cells. As they move through smaller and smaller arteries, then capillaries, they eventually get into very, very small capillaries and spaces between tissues and fibers. The chemistry of your body tissues tries to be homeostatic in regards to oxygen and other cellular inputs and also carbon dioxide and other cellular waste. The hemoglobin molecules chemically release the oxygen into depleted spaces and tissues and similar processes cause your cells to take up carbon dioxide to ferry back to your lungs. It’s actually a process of chemistry as opposed to some sort of “physical” process. Also, while we have a circulator system, the easily observable parts – veins, arteries and many capillaries – are just then big parts, like freeways and major streets. Most of your tissues are filled with very small, even invisible capillaries where the red blood cells actually go to release their oxygen and pick up waste products, similar to how you take a freeway to the store and back, then take a major street to get to your neighborhood, and then a small surface street to get to your house. The veins and arteries are just transport systems for blood, they’re not where the blood is doing it’s work. There are a few other steps in the process of how the oxygen actually moves in and out of cells, but ultimately its a process of chemical diffusion.
Latest Answers