White blood cell defense mechanism

The article was professionally consulted by Specialist Doctor II Ho Viet Le Diem - General Internal Medicine - Department of Examination & Internal Medicine - Vinmec Central Park International General Hospital.

White blood cells travel through the bloodstream and destroy viruses, bacteria, and foreign objects in the human body that can cause disease or inflammation. White blood cells form a defensive barrier to protect the body from foreign objects.

Blood is made up of red blood cells, white blood cells, platelets, and plasma. The number of white blood cells (also known as immune cells) makes up only 1% of the blood but plays a very important role in fighting disease.
Bone marrow makes blood stem cells, and these blood stem cells make red blood cells, white blood cells, and platelets. White blood cells are stored in the blood and lymphatic tissues. Because the lifespan of white blood cells is only 1-3 days, the bone marrow continuously produces blood stem cells to turn into white blood cells.

Monocytes: 5 - 12% of white blood cells are monocytes. They live longer than other types of white blood cells and have a role in 'cleaning up' dead cells and fighting bacteria. Lymphocytes (T lymphocytes and B lymphocytes): Lymphocytes are also important in the immune system. T lymphocytes have a direct role in destroying some foreign objects in the human body. B lymphocytes play a role in humoral immunity by producing antibodies that are able to "remember" the cause of an infection and recognize the next time an infection occurs.

Neutrophils: About 50% of white blood cells are neutrophils. Neutrophils are usually the first cells to respond when a foreign object enters the body such as bacteria or viruses. They also have a role in sending warning signals to other cells in the immune system to promptly deal with foreign objects. The lifespan of neutrophils is only about 8 hours, but the human body produces 100 billion neutrophils per day. Eosinophils: Eosinophils play a role in fighting inflammation caused by parasites (such as helminths). However, the most important role of eosinophils is to fight foreign objects that can trigger allergic reactions. Eosinophils make up only 5% of white blood cells and are present in high concentrations in the gastrointestinal tract. Basophils: The most important role of basophils is in asthma. They secrete chemicals like histamine to help the body respond appropriately to foreign objects.

The cause of an elevated white blood cell count is usually an infection. However, an elevated white blood cell count can also signal a number of other conditions or be caused by a number of other conditions:
Cancers such as blood cancers and bone marrow cancers (leukemia), lymphoma , myeloma Inflammatory diseases such as inflammatory bowel disease and autoimmune diseases Trauma types from fractures to stress Asthma and allergic reactions Exercise Pregnancy .

Articles refer to sources: wellhealth.com, Urmc.rochester.edu