The function of leukocytes (white blood cells) and their normal numbers in the body

Leukocytes are one of the four components of human blood. Although the numbers are not as many as red blood cells, the function of white blood cells is no less important. What are the main roles of white blood cells in our body? What is the normal number of leukocytes in healthy people? Check out the full explanation below.

What are leukocytes?

Leukocytes, or white blood cells, are a component of blood that functions for the immune system, aka the immune system. Normal adult leukocytes range from 4,500-11,000 / microliter (mcL) of blood. If the results are abnormal, you may have a condition called leukocytosis (too high white blood cells) or leukopenia (white blood cells too low).

Leukocytes function to track and fight against microorganisms or foreign molecules that cause disease or infection, such as bacteria, viruses, fungi, or parasites. Not only fighting germs that cause disease and infection, leukocytes also protect us from foreign substances that may threaten the condition of the body.

Leukocytes have various types. There are several types of white blood cells that immediately work to kill germs completely. There are also those that produce "weapons" in the form of antibodies to protect the body. Do not stop there, there are also other types of white blood cells that function as information to the "invading" leukocyte troops that the disease has occurred.

What are the types of leukocytes and their functions?

There are five different types of leukocytes that develop specific tasks based on the capabilities of each and the types of foreign molecules that are resisted.

The kinds of white blood cells, namely neutrophils, basophils, eosinophils, monocytes, and lymphocytes.

1. Neutrophils

Nearly half of the white blood cells in the body are neutrophil cells. Neutrophils are the first cells of the immune system to respond by attacking bacteria or viruses.

As the main shield, neutrophils will also send signals that alert other cells in the immune system to respond to these bacteria or viruses. Neutrophils are generally the pus that comes out of an infection or wound on your body.

These leukocytes will come out after being released from the bone marrow, and stay in the body for only about 8 hours. Your body can produce about 100 billion neutrophil cells each day.

2. Eosinophils

Eosinophils are a type of leukocyte that functions to fight bacteria and parasitic infections (such as worms). Eosinophils also work when a person has an allergic reaction. When the number of eosinophil cells is excessive, this is generally the result of an immune response to the allergen.

Eosinophils make up only about 1 percent of the white blood cells in your bloodstream. However, in the digestive system the numbers are higher.

Eosinophils not only bring benefits to the body, but also harm. In extreme conditions, such as in toxic erythema disease, eosinophils can act as useful elements or simply observers.

3. Basophils

Basophils are a type of white blood cell that account for only about 1 percent. Basophils function to increase non-specific immune responses against pathogens (germs that cause disease, such as bacteria or viruses). Basophils are the cells best known for their role in giving rise to asthma.

When you are exposed to asthma triggers, such as dust, basophil cells will release histamine. These basophils can cause inflammation in your respiratory tract.

4.Lymphocytes (B lymphocytes and T lymphocytes)

Lymphocytes are leukocytes that are important for maintaining the immune system. There are two main types of lymphocytes, namely B cell lymphocytes and T cells.

B lymphocytes function to make antibodies to fight bacteria, viruses, and toxins that attack your body. Meanwhile, T lymphocytes are responsible for destroying the body's own cells that have been attacked by viruses or become cancerous.

T lymphocytes are "fighters" who fight against the invaders head on. These types of lymphocytes also produce cytokines which are biological substances that help activate other parts of the immune system.

T lymphocytes are still divided into several types, namely:

• T cells: are in charge of releasing proteins called cytokines that help direct the response of other white blood cells.
• Cytotoxic T cells (also known as natural killer T cells): capable of releasing molecules that kill viruses and other foreign bodies.
• Memory T cells: will appear after the body has fought infection. This is useful so that the body can more easily deal with similar infections at a later date.
• Regulatory T cells (also known as suppressor T cells): help regulate other T cells to prevent attacking the body's own cells.

5. Monocytes

Monocytes are leukocytes that can be described as "garbage trucks". Monocytes originate from the spinal cord which carry out movement in the blood and spleen. Monocytes are known for their ability to recognize "danger signals".

This type of leukocyte accounts for about 5 percent of all white blood cells. The function of monocytes is to move to the tissues in the body while cleaning the dead cells in them.

Monocytes can be divided into two types of cells, namely:

• Dendritic cells, namely antigen-presenting cells by marking foreign bodies that need to be destroyed by lymphocytes.
• Macrophages, which are cells that are larger and outlive neutrophils. Macrophages can also act as antigen presenting cells.

What is the normal leukocyte count?

According to the standards stated by the American Associaton of Family Physician (AAFP), the following are normal leukocyte levels when calculated based on age categories:

• Newborn children: 13,000-38,000 / mcL
• Infants and children: 5,000-20,000 / mcL
• Adults: 4,500-11,000 / mcL
• Pregnant women (third trimester): 5,800-13,200 / mcL

What causes the leukocyte count to rise or fall?

As explained above, leukocytes are important for maintaining the body's immune system. If the leukocyte count is too low, you are susceptible to disease. However, too high white blood cells can also be dangerous.

A low leukocyte test, which is less than 4,000-4,500 per microliter of blood, can indicate that your body may not be able to fight off the infection as it should. This condition is known as leukopenia.

Some conditions that cause low white blood cells include:

• Severe infection
• Bone marrow damage or disorders, including aplastic anemia.
• Autoimmune diseases such as lupus.

Meanwhile, if the leukocyte test result is high, which is above 11,000 / mcL, this indicates an infection or serious condition that needs to be investigated further. This condition is known as leukocytosis.

• Infection
• The presence of cancers such as leukemia, lymphoma, and myeloma. This condition occurs when many white blood cells are produced
• Inflammation such as inflammatory bowel disease and autoimmune disorders
• Physical or mental trauma, such as a fracture and stress
• You are pregnant. pregnancy can make the white blood cell count increase
• Asthma and allergies are characterized by an increase in eosinophil white blood cells