Human Blood is actually a liquid connective tissue made of mainly plasma and more 3 important components like the red blood cells, the white blood cells and the platelets.

WHAT IS THE MAIN FUNTION OF BLOOD?

The main functions of blood are:

  2. Maintain the body immunity.

  Furthermore, blood helps in healing of wounds and also keeps our body temperature steady.

  WHAT ARE THE MAIN COMPONENTS OF THE LIQUID?

  Blood is mainly made of about 22% solids and 78 % water. The components of human blood are:

• Plasma

• Red blood cells (RBC)

• White blood cells (WBC)

• Platelets

• Fat globules

• Chemical substances including carbohydrate, hormones, electrolytes, proteins.

• Gases like oxygen & carbon di oxide.

PLASMA: This is a straw colored liquid with 92% composed of water. However, the remaining 8 % of this liquid contains more than 200 substances, including minerals, vitamins, proteins, sugar, fats and some other minerals acting as chemical messengers and help fight diseases. As more than the half of blood is made of this circulating liquid, the RBCs, WBCs, and Platelets as well as other components of blood move throughout the system remaining suspended in plasma. Generally, average adult body contains six pints of plasma out of 10 –12 of pints of blood. Plasma carries nutrients to all parts of the human body and carries off waste products to the excretory organs.

 RED BLOOD CELLS (RBC): This component makes up 40-50%of total blood volume and is responsible for providing the red color to the blood due to the oxygenated haemoglobin present in it. As it contains the iron containing protein haemogloobin, which is very much essential component helping in carrying of oxygen from lungs to the entire body cells and at the some time it picks up carbon dioxide and carries it back to the lungs to be exhaled, serves the most impotent function of blood to keep life possible. The oxygen released by the red cells help in the conversion of nutrients in food such as milk, red meat and green vegetables into energy. The RBCs (erythrocytes) are disc shaped, round and tiny microscopic cells without nuclei. These red cells are produced in bone marrow at a rate of 2-3 million per second from the stem cells by hematopoiesis. Each red cell contains about 270,000,000 iron-rich hemoglobin molecules.

WHITE BLOOD CELLS (WBC):Only 1% of total blood is composed of WBCs or leucocytes of variable number and types. Normally these are produced by the same hematopoiesis process in the bone marrow, and in some cases in the thymus gland. Other than blood, lymphocytes also occur in the spleen, liver and lymph glands. There are many specialized sub types of the cells that take vital part in our immune system. Among them the 5 main sub types are lymphocytes, monocytes (both agranular), basophils, neutrophils and eosinophils (all 3 are granular).

 •Lymphocytes (20-25%) - recognize surface markers on cells and targets them for destruction if foreign to the body;

•Monocytes (3-8%) - formed in bone marrow, monocytes migrate into connective tissue and become macrophages; •Basophils (5-1%) - acts on smooth muscle and Blood cell walls;

•Eosinophils (60-70%) - acts against infestations of parasitic lar

•Neutrophils (2-4%) - the first line of defense, 100 billion mature neutrophils are released into the body everyday.

  The primary function that white blood cells, or leukocytes, play is to fight against various bacterial, viral, fungi, and parasitic infections.

 • WBCs help in healing of wounds not only by fighting infection but also by ingesting matter such as tissue debris, dead cells and old erythrocytes.

 • Gives us protections from foreign bodies such as allergens that enter the blood stream.

 • Also protects against mutated cells, such as cancer.