Question

The number of WBCs per mm3 of human blood is ideally.
A. 8000
B. 7000
C. 6500
D. 6000

Answer 1

Hint: WBCs are white blood cells which are known as immunity cells of the body, these cells provide immunity against various infections, white blood cells are of many types such as basophils, eosinophils and some other cells which work together to fight against disease and form white blood cells.

Complete answer:
White blood cells are called leukocytes which are the cells of the immune system and present in the blood and lymphatic system. White blood cells are different from blood cells due to the presence of nuclei in their cell. The WBC are broadly divided into two groups such as granulocytes or agranulocytes, which are associated with five types of cells such as neutrophils, eosinophils, basophils, monocytes, and lymphocytes. These cells perform different functions against disease. The number of white blood cell or leucocytes in the blood is varied and influence by the infections in the body, the number of WBCs is 4000 to 11,000 per microliter of blood but the average number of cells are 8000 cells per cubic millimeter, which make 1 percent of the total blood volume in a normal adult. The decrease in the count of white blood cells is called leukopenia, which is the indication of a weaker immune system. WBC circulate with blood throughout the whole body. Some of the leukocyte cells move into the tissue of the body where it resides permanently and these cells have a specific name that depends on the residence tissue, such as kupffer cells which are the transformed macrophages cells in the liver and play a role in the immune system.
Hence, the correct Option is A.

Note: The disorder in leukocytes or white blood cells will lead to dysfunctioning of the immune system. Some of the disorders related to leukocytes are named leukopenia due to a decrease in WBC, Neutropenia which occur due to a decrease in neutrophils cells, lymphocytopenia, and many more.