Red Blood Cells
The structure of red blood cells (or erythrocytes) can be described as follows:
- Immature erythrocytes have a nucleus but mature erythrocytes have no nucleus.
- Red Blood Cells have a "prosthetic group" (meaning "in addition to" - in this case, in addition to the cell). The active component of this prosthetic group is Haem.
- Haem relies on the presence of iron (Fe).
- Haem combines with oxygen to form oxyhaemoglobin.
- Red Blood Cells are eventually broken down by the spleen into the blood pigments bilinubin and bilviridin, and iron. These components are then transported by the blood to the liver where the iron is re-cycled for use by new red blood cells, and the blood pigments form bile salts. (Bile breaks down fats.)
- Have a longevity of approx. 120 days.
- There are approx. 4.5 - 5.8 million red blood cells per micro-litre of healthy blood, although there are variations between racial groups and between men and women.
The most important function of red blood cells is that of:
- Transporting oxygen around the body.
For more information about other components (sometimes called the 'constituents') of blood, see the page about the structure and functions of blood. This may interest students of holistic massage, reflexology, beauty therapies, or health-related courses.