DISORDERS.

There are certain disorders, related to the blood. Some of them are discussed below:

i) Leucaemia (Blood Cancer). Cause. It is the result of uncontrolled production of white blood cells (leucocytes). This is caused by a cancerous mutation of a myelogenous or lymphogenous cell.

Characterized by.

The Leucaemia is usually characterized by greatly increased numbers of abnormal white blood cells in the circulating blood. These white blood cells are not completely differentiated, and so are defective. Spread. Myelogenous cells (bone marrow cells) are in the bone marrow – and may spread throughout the body, so that white blood cells are produced in many other organs.

Types.

Leucaemia may be of different types depending on the type of white blood cells, which are undifferentiated and being produced at a faster, than normal rate. There may be neutrophilic leucaemia, eosinophilic leucaemia, and basophilic leucaemia, monocytic or lymphocytic leucaemia.

Blood replacement.

It is a very serious disorder and the patient needs to change the blood regularly with the normal blood, got from donors. Cure. It can be cured by bone marrow transplant – which is in most cases effective, but very expensive treatment.

ii) Thalassemia (G. Thalassa = The sea; haema = blood). It is also called Cooley‟s anaemia on the name of Thomas B. Cooley, American pediatrician.

Haemoglobin abnormality.

It is a genetically transmitted haemoglobin abnormality. Haemoglobin molecule in most cases, does not have (beta chains in it, instead F.chain is present (F is foetal haemoglobin).

Characterized by.

It is characterized by the presence of microcytes, by spleenomegaly (enlargement of spleen) and by changes in the bones and skin.

Blood replacement.

The blood of these patients is to be replaced regularly, with normal blood. Cure. It can be cured by bone marrow transplant – which is very expensive – and does not give 100% cure rate.

iii) Oedema. It means the presence of excess fluid in the tissues of the body. The excess fluid may be in the cells, or outside the cells.

Intracellular Oedema.

The intracellular Oedema is caused by osmosis of water into the cells, and cause, depression of metabolic systems (due to lack of nutrition and O2 in the tissues) especially and the Na-pump. Extracellular Oedema It may be the result of :

i) Abnormal leakage of fluid from the blood capillaries or failure of the lymphatic system to return fluid from the interstitial fluid.

ii) Oedema is caused by renal retention of salts and water. Disturbances. Oedema disturbs the exchange and concentration of minerals and ions in the blood and body cells, affects blood pressure, increases heart load etc.