Describe Is WBC(White Blood Corpuscles):-hello friends welcome to yourstudynotes.com today post is WBC. so I Hope this topic is very useful in your study. so let’s start this topic.
Leucocytes or White Blood Corpuscles(WBCs):-
They are circular or amoeboid, nucleated wandering cells. They have the capacity to squeez out from blood capillaries inti tissue fluid where they destroy pathogens and foregin antigens to product the body. The moving out of WBCs form capillaries is called Diapedesis.They are larger size than red blood corpuscles. There are about 6000-8000 WBCs per mm³in a healthy adult man. It means the ratio of white blood corpuscles to red blood corpuscles is 1: 700. Abnormal reduction in the number of white blood corpuscles is called Leukopenia, while the abnormal increase in their number is called Leucocytosis. The number of WBCs is also increased abnormal in patients of blood cancer . This condition is know as Leukemia. The production of white blood corpuscles is Leucopoiesis. They are produced in bone marrow, peyer’s patches of intestinal mucosa, lymph nodes, thymus and spleen.
There are following two groups of white blood corpuscles:
cytoplasm of such type of white blood corpuscles is agranular or without granules and their nucleus is spherical , not lobed. Granulocytes are of two types.
Lymphocytes are smallest white blood corpuscles and measure 8-12μ in diameter. They from 30% of total white blood corpuscles. Their nucleus is spherical and large in size, Therefore, the cytoplasm is restricted to peripheral portion only. On the basis of their size they are grouped as small and large lymphocytes. Lymphocytes are produced in Lymph glands. Their main funcation is to produce antibodies.
They are comparatively large sized and measure 12-15μ in diameter. Monocytes from about 6% of total leucocyte count. They have large, kindly shaped or horseshoe shaped nucleus. These are produced in lymph nodes and spleen. They are actively wandering cells engaged in phagocytosis, and are converted into macrophages after reaching tissue fluid. In tissue fluid they dispose off dead or worn out cells.
There are many granules in the cytoplasm of such types of white blood corpuscles, and their asymmetrical nucleus is divided into two more or lobes. On the basis of shape of nuclei and staining reaction of the cells the granulocytes are divided into following three types
They are most active white blood corpuscles and measure 10-12μ in diameter, They are also known as heterophils. They are about 66% of total leucocyte count. Their granules are smaller but more numerous and can be stained by acidic or alkaline both type of stains . Their granules are actually lysosomes and Golgi bodies. The nucleus of neutrophils is made of 3-4 lobes. Neutrophils are actively wandering phagocytic cells. A small body called Drumstick is found attached with the nucleus of neutrophils of females. Like bar body drumstick is also produced by a modified X chromosome.
Eosinophils measure 10-15μ in diameter and form 2-4% of total leucocyte count. They have larger granules and are stained by acidic stains like Eosin. Their nucleus is bilobed and both the lobe are connected by a thread like structure . Their exact function is not known but their number is increased many fold during allergy and infection. This state is called eosinopphilia.
Basophils are granulocytes measuring 8-10μ in diameter and form 0.5-2% of total leucocyte count. Their granules are less numerous but larger in size and can be stained with basis days like methylene blue. Their nucleus is made of 2 to 3 lobes or ‘S’ shaped. Basophils secrete heparin and histamine. Heparin is an anticoagulant and histamine promotes inflammatory reaction.