Red blood cells (Erythrocytes) contain haemoglobin, and transport oxygen to the cells, and the majority of Carbon Dioxide back to the lungs. These cells are bioconcave in shape, making them more flexible, and increasing their overall surface area. This aids the uptake of oxygen.
Red blood cells only have a short life span, and live about 120 days, before being ingested by phagoccytic cells in the liver and spleen. They are made in the red bone marrow, and in adults can be produced in the thoracic boes, vertebrae, cranial bone and ends of the femur and humerus bones.
The fascinating thing about red blood cells is that the blood contains approximately 25 trillion, and they have to be replaced at about 3 million per second - that's pretty speedy! The condition Anaemia is the deficiency of red blood cells
The transport of oxygen is assisted by the red blood cells. The pigment haemoglobin binds four oxygen molecules to every one. Oxyhaemoglobin then forms. The oxygen molecules are carried to individual cells in the body tissue, where they are then released. This binding of oxygen is a reversible reaction.
Carbon dioxide diffuses from the tissues into the red blood cells and combines with water to form carbonic acid. This is generally a slow reaction, but it is accelerated in the red blood cell by the presence of the enzyme carbonic anhydrase. Most of the carbon dioxide is carried in the red blood cells rather than the plasma because of this enzyme.
Bibliography:
cgpartnership handout, week 24
No comments:
Post a Comment