Red blood cells are one of the type of blood cells which the widely distributed cells in the blood. These are also called as blood corpuscles because they are like coins and also lack other cell organelles. Further they float freely in the blood due to their shape and low weight. They are abbreviated as RBC’s. These cells are also termed as erythrocytes due to their red colour and are the reason for the red coloration of the blood. They are formed in the bone marrow. They have a life span of 120 days. During their continuous flow inside the blood, they get worn out and removed from blood by liver and spleen.
Blood corpuscles Shape & Size:
As shown in pic, they are biconcave discs with a mean diameter of 7.8 micrometers and a width of 2.5 micrometers at the thickest point and 1 micrometer or less in the center. Their volume is 90 to 95 cubic micrometers.
Concentration of blood corpuscles or RBC’s:
The concentration of red blood cells per cubic millimeter is 5, 200,000 to 4,700,000 varying between men and women. Their decline is seen during pregnancy and other severe disease conditions. Decrease in count results in anemia.
Formation and content: They are formed in the red bone marrow of long bones.They internally have a pigment called hemoglobin which is a protenacious substance in complex with iron molecules. This pigment helps to carry oxygen by these cells.
Red blood cell function:
1. They transport oxygen from lungs to the tissues and cells all over the body. They do it by reversible combination of oxygen with hemoglobin within them.
2. The help in transport of carbon dioxide from tissues to lungs. They contain carbonic anhydrase enzyme that catalyzes the reversible reaction between carbon dioxide (CO2) and water to form carbonic acid (H2CO3), thereby increases the rate of the reaction. Thus formed carbonic acid is transported by water in the blood.
3. Due to presence of hemoglobin which can act as acid-base buffer, the red blood cells are responsible for the acid-base buffering power of whole blood.