Red Blood Cells are produced in the bone marrow which is closely attached to a macrophage. When it has expelled its nucleus which is ingested by the macrophage, it leaves the bone marrow and becomes know as a reticulocyte. It then goes through another stage and has to lose its organelles. Once this has happened the red blood cell (rbc) has fully matured in to an Erythrocyte.
Structure - An RBC is biconcave in shape and very flexible. It has the ability to move single file through capillaries without breaking.
An RBC is 1/25,000 of an inch in size.
An RBC can last about 120 days in the blood stream. Once it has become old it is injested by the macrophages in the liver and spleen.
Interesting Fact; Men contain more rbc's per cubic millimetre than women. Men - 5,200,000 pcm; Women - 4,600,000 pcm.
Approximately 40-45% of blood is rbc's.
The red colouring of the Erythrocyte (rbc) comes from a substance called Haemoglobin- a simple protein, and iron pigments. When they are exposed to Oxygen their colour becomes bright scarlet.
Function - It is the red blood cells main function to transport oxygen from the lungs to the cells in the body, where needed. The oxygen is diffused in to the haemogloin protein with in the red blood cell. It circulates around the body as oxyhaemoglobin. In turn, as the oxygen is being diffused in to cells, carbon dioxide is diffused from the cell in to the rbc, and in some cases plasma.
Carbon dioxide combines with the water in the rbc to form carbonic acid. Normally a slow reaction, however, this process is accellerated by the enzyme carbonic anhydrase.
Carbonic acid then seperates in to bicarbonate ions and hydrogen ions. Hydrogen ions combine with the haemoglobin, and the bicarbonate ions go in to the plasma. The remaining Co2 is either dissolved in the plasma, or diffused diectly in to the haemoblobin for gaseous exchange with the alveoli.
Bibliography
CG Partnership handout, wk 22, The blood system
CG Partnership handout, wk 24, Blood
Hi Emma,
ReplyDeleteI like your new look blog; "view my complete profile" looks kind of spooky but cool!
"Men contain more rbc's per cubic millimetre than women. Men - 5,200,000 pcm; Women - 4,600,000 pcm" I read this also. I wonder why this is?
Alan