Blood is the life giving fluid that flows through the human body. None can live without it. The heart pumps blood to all our body cells, supplying them with oxygen, chemicals and nutrition. Simultaneously, the blood also carries away the carbon dioxide and waste products from the cells. It fights infections and keeps our body temperature normal and steady. In an adult of average age, there is about five litres of blood while an infant may have around 250 millilitre.
Composition of Blood:- Blood consists of 3 types of formed elements (cells) that flow in a watery liquid called plasma inside the blood vessels. The three types of cells are: red blood cells, white blood cells, platelets.
1. Red Blood Cells (RBC):- RBC contains only haemoglobin which is its main factor. It carries oxygen to body tissues and removes carbon dioxide. Haemoglobin contains iron and imparts red colour to the cells.
Abnormally low levels of red blood cells or haemoglobin cause Anaemia. In Anaemia, the oxygen carrying capacity of blood is reduced and it can not meet the needs of body tissues. Haemoglobin may be low due to low nutrition, infection, poor formation and diseases. Besides blood loss from injury often results in Anaemia.
2. White Blood Cells (WBC):- WBC are of 5 types. They are Neutrophils, Lymphocytes, Monoytes, Basophils, Eosinophils. Each type plays a distinct and important role in helping the immune system to fight against infection. Neutrophils contain granules of bacteria killing enzymes in cytoplasm.
Leukopenia is a blood disorder due to a low number of white blood cells. Neutropenia is the most common type of leucopenia. Neutropenia suffering people have increased risk of infection. Infection fighting ability is reduced against harmful bacteria in Neutropenia.
Neutrophils can squeeze through capillary walls into infected tissues where they kill the invaders and then engulf the foreign body by phagocytosis. This is a never ending task. Neutrophils have the shortest life span (2 to 3 days) of all blood cells. After chemotherapy is given, blood cells count goes down and Neutropenia is the first clinical sign.
3. Platelets:- These are also known as thrombocytes and help to stop bleeding through formation of a blood clot.
Low levels of plateles is called Thrombocytopenia. In this condition the blood coagulates extremely slowly. Thrombocytopenia causes sudden, unexplained bleeding, severe bleeding from minor injuries and also the bleeding of joints and internal organs.
In day to day life we have to understand the importance of complete blood count-CBC Tests. A CBC test provides a major of the levels of the different types of cells in our blood. Appropriate treatments for blood disorder may be sought depending upon the result of low or high count of red or white blood cells, platelets etc.
There is yet no substitute of blood. Therefore blood donation saves life. Our one bottle of blood may create a wide gap from death to life. Donating blood is a social responsibility and the most noble gift. So donate blood and save life.