Blood is the red fluid that flows in our body. Its main function is to distribute oxygen and nutrients. Blood is actually a suspension of cells in plasma.
Most of our blood is a colorless liquid called plasma. The red cells in it make it look red.
The plasma, a clear yellow fluid, accounts for about 55 per cent. The main cell elements are the red blood cells, and there are also the white blood cells and the platelets.
White blood cells: these fighting white cells kill germs that get into the body. They are bigger than red cells, but we don’t have so many of them.
The red blood cells and their function
Our blood stream flows round the body like a river, to bring supplies to all the body cells. The human body is made up of tiny bits called cells. They need food and a special gas called oxygen to live and grow and work.
The red blood cells bring oxygen from the lungs to the body cells. During the process, they also take away the waste gas made by body cells as they work. Bits of food are carried by the blood stream. The body cells pick up what they need as the blood flows past, while the blood takes away any rubbish made by the cells. It is cleaned as it goes through the kidneys.
Red blood cells are produced by the bone marrow, and they are released into the body system where they survive for 120 days, with new ones continuously produced and then broken down throughout the body.
In the liver and spleen, they are broken down into haem (where iron is attached) and globin, which is the protein matrix (the substance between cells). These components are re-used by the body, and thus the whole cycle of production begins again.
Red blood cell production involves mainly the building up of haemoglobin, which is designed to take oxygen in the lungs and unload it in the tissues for bodily functions. It transports carbon dioxide from the tissues to the lungs for elimination and exchanges this for oxygen.
reference: what’s in the blood? by netwellness.org