THE BLOOD

Once again you do not need too much detail to pass any entrance test so we will keep it very short and simple. Just the basics is what you need!

The blood is made up of the plasma (liquid part) and the formed cells (blood cells). It distributes nutrients to the cells, carries oxygen from the lungs to the cells, carbon dioxide from cells to the lungs, transports waste to various organs to be excreted or degraded, transports hormones and various chemicals, and it helps to maintain the body's temperature.

Picture showing the components of blood.

Plasma is made up of serum and fibrinogen. Serum is the part of plasma that does not clot. Fibrinogen is inactive but when activated to fibrin, then clotting occurs.

The formed cells arise from the bone marrow. They are:
1. Erythrocytes (Red Blood Cells a.k.a RBC's): These transport oxygen. Oxygen is carried by hemoglobin in the RBC. Iron is needed for RBC production in addition to other nutrients such as Vitamin B.  "Haem" represents iron and "globin" represents protein. So hemoglobin is iron plus attached to four protein units. Lack of iron can lead to reduced RBC production referred to as anemia. RBC's have a life span of 120 days.

2. Thrombocytes (Platelets): These are not actual cells but fragments of cells. They are invlove with the formation of blood clots.

3. Leucocytes (White Blood Cells a.k.a WBC's): These cells defend the body against infections. These are the types of WBC's: Neutrophils, Eosinophils, Basophils, Lymphocytes, and monocytes. Basically, the neutrophils are more involved in fighting bacteria infections. Eosinophils and basophils play roles in allergic reactions and parasitic infections. Lymphocytes are vital to fighting viral infections and monocytes are like scavengers that get rid of cancer cells and dead cells including bacteria.