Body Fluids and Circulation – Solutions
1. Name the components of blood and mention one major function of each of them.
Blood is composed of cells bathed in a fluid matrix plasma. The cells constitute about 45% of the blood by volume, while the other 55% is represented by the plasma. The plasma is a pale yellow liquid and consists of 90% water and 10% of a variety of substances in solution and suspension.
Blood cells consist of erythrocytes (red blood cells), leucocytes (white blood cells) and platelets.
Erythrocytes are red blood cells devoid a nucleus. They are produced by a process called hemopoiesis. RCB’s have an average life span of about 120 days, after which they are destroyed in the spleen. RCB’s contains haemoglobin, a pigment that can combine reversibly with oxygen. They also contain the enzyme carbonic anhydrase, which plays an important role in the transport of carbon dioxide.
Leucocytes are larger than erythrocytes and are much less in number.