WHITE BLOOD CELLS
White blood cells (WBC's) are the mobile units of the body's immune system. They move at will all over the body. Where our country may take weeks to months to deploy troops, our body does it in seconds.
Your white blood cells are produced both in the bone marrow and in the lymphatic system. WBC's are divided into two groups:
Granulocytes: Have distinct granules present in the cytoplasm and multilobed nuclei and are also called polymorphonuclear leukocytes. They consist of your neutrophils, basophils, and eosinophils.
Non-granulocytes contain no granules and are your monocytes and lymphocytes.
The endocrine system along with site inflammation/infection is responsible for regulation of production, storage and release of leukocytes into the blood stream as well as their destruction or disintegration.
The average WBC lives for 13-20 days and is destroyed by the lymphatic system and eliminated from the body thru fecal matter.
The WBC's that are produced in your bone marrow originate from cells called myelocytes.
A myelocyte will mature into a promyelocyte and either form a megakaryocyte or monocyte.
1. Magakaryocytes split to form granulocytes that will produce your neutrophils (polymorphonuclear cells), eosinophils, and basophils/mast cells and your monocytes
2. Monocytes grow to become tissue macrophages and live for years.
These cells utilize a number of weapons in their arsenal such as:
¬ Phagocytosis, whereby some of these cells, such as neutrophils and macrophages encapsulate and use proteolytic enzymes to digest bacteria, virus etc.
¬ Diapedesis, whereby neutrophils and monocytes squeeze through blood vessel pores and move about the body
¬ Ameboid movement for neutrophils and macrophages, and
¬ Chemotaxis a weapon whereby chemicals from bacteria cause neutrophils and macrophages to be attracted to them.
¬ Leukocytes also produce, transport and distribute antibodies as part of the immune response.
It is mostly the monocytes and neutrophils that destroy bacteria and virus.
Basophils and mast cells, on the other hand, liberate heparin, an anti-coagulant, into the blood. Basophils and mast cells also release histamine, bradykinnin, and serotonin. Therefore, they are involved with allergic reactions and speed up the removal of fat particles after a meal. The lifespan of a granulocyte is 4-5 days.
The WBC's that are produced by the lymph tissue are called lymphocytes and plasma cells. These cells are also produced in the spleen, thymus, tonsils, and bone marrow. Lymphocytes keep circulating between the lymph, blood, and intercellular spaces via diapedesis.
WBC'S cells/mm3
ADULTS 4,500-10,000
BLACK ADULTS 3,200-10,000
CHILDREN
2MONTHS 6 YEARS 5,000-19,000
6-18 YEARS OF AGE 4,800-10,800
WBC'S are increased in (leukocytosis >11,000/mm3:
1.Neutrophilic leukocytosis or neutrophilia
Lymphocytic leukocytosis or lymphocytosis
Monocytic leukocytosis or monocytosis
Basophilic leukocytosis or basophilia
Eosinophilic leukocytosis or eosinophilia
Acute infections
Measles, pertussis
Trauma or injury
Malignant neoplasms
Toxins, uremia, eclampsia
Acute hemolysis
Polycythemia vera
Tissue necrosis
Over exposure to sunlight
Exercise
Pain
Stress
Pain
Cold
WBC's are decreased (leukopenia <4,000/mm3
1. Viral infections
2. Toxic reactions
3. Hyperspleenism
4. Bone marrow depression
5. Antibiotics
6. Barbiturates
7. Antihistamines
8. Anticonvulsants
9. Heavey metal intoxication
10. Diuretics
11. Cardiovascular drugs
12. Bone marrow disorders
13. Leukemia
14. Pernicious anemia
15. Aplastic anemia
16. Marrow occupying lesions such as tumors