Blood is a transport fluid that supplies various substances to all the body parts. The study of blood is known as Haematology.
Blood
Blood carries gases, liquids, digested food materials, hormones, salts and provides different parts of the body.Blood collects wastes and carries them to excretory organs.
Components of Blood: The major components of Blood are Plasma and Cells.
Plasma: It is a liquid portion of blood. It contains salts, glucose, amino acids, hormones and electrolytes.
Types of blood cells: Blood includes Red Blood Cells, White Blood Cells and Blood Platelets.
Red blood cells are also known as erythrocytes and are red in colour. They have a red colour protein called haemoglobin, which helps in the transportation of Oxygen.
Red blood cells are coin shaped and the nucleus is absent. But animals like camels and llamas have nucleus in red blood cells.
1ml of blood contains 5 million Red Blood Cells. Their life span is 120 days. RBC are produced in the Bone Marrow.
White blood cellsThese are also known as Leukocytes. These cells do not have Haemoglobin.
One microliter of blood contains 4,500 to 11000 white blood cells. These are produced with a bone lifespan of 13 to 20 days.
White blood cells are categorised into two types. They include Granulocytes and Agranulocytes.
Granulocytes: They have granules in the cytoplasm. These are three types. They are Neutrophils, Basophils and Eosinophils.
Agranulocytes: These do not have granules in the cytoplasm. These are two types. They are Monocytes and Lymphocytes.
The main function of white blood cells is fighting against microorganisms.
Blood platelets: These are also known as Thrombocytes. These are colourless and irregular in shape. They are produced in the Bone Marrow.
One microliter blood contains 150,000 to 450,000 platelets. The life span is ten days. These are responsible for the clotting of blood at the time of injuries.