White blood cells are part of the immune system that helps protect your body from infections. They move through your blood and tissues to fight off germs or harmful organisms that might cause illness or injury.
What are White Blood Cells?
White blood cells, or leukocytes, are a crucial part of the composition of blood and help protect your body from infections. They are an essential component of the immune system and travel through your blood to fight off illnesses or respond to injuries. Their primary role is to defend the body against harmful invaders such as bacteria, viruses, and other pathogens.
Function
What do white blood cells do?
White blood cells guard your body against infections. They move through your blood and tissues to find the infection site, like a general leading an army. Once they locate the threat, they alert other white blood cells to join the fight. Together, they produce special proteins called antibodies to attach to the harmful organism and destroy it, protecting your body.
FAQs on Anatomy of WBCs
Our white blood cells move through our bloodstream and pass through blood vessel walls and tissues to find the site of an infection.
Despite their name, white blood cells are actually colorless. However, when viewed under a microscope and stained with dye, they can appear light purple or pink. These tiny cells have a round shape and a clear center, known as the nucleus.
White blood cells are so small that you can only see them under a microscope.
White blood cells make up about 1% of your blood. There are more red blood cells in your body than white blood cells.
White blood cells are formed in the soft tissue inside your bones, called bone marrow. Two types of white blood cells, known as lymphocytes, develop in different areas: T cells grow in the thymus gland, while B cells grow in the lymph nodes and spleen.
White blood cells come from stem cells, which change into other types of cells in the body. These stem cells are located in the soft tissue of your bones, known as bone marrow.
Types of White Blood Cells?
White blood cells (WBCs), also known as leukocytes, are an essential part of the immune system. They help protect the body against infections, foreign invaders, and harmful organisms. White blood cells can be classified into two main groups based on the presence or absence of granules in their cytoplasm:
- Granulocytes (WBCs with granules in their cytoplasm)
- Agranulocytes (WBCs without distinct granules in their cytoplasm)
Here’s an overview of the different types of white blood cells and their functions:
Granulocytes
Granulocytes contain tiny granules in their cytoplasm, which are filled with enzymes that help destroy foreign particles and microorganisms. The three main types of granulocytes are:
1. Neutrophils
- Function: Neutrophils are the first line of defense against bacterial infections. They are the most abundant type of white blood cell and are known for their ability to engulf and destroy bacteria and fungi through a process called phagocytosis.
- Characteristics: Neutrophils are fast responders and can travel to the site of infection quickly. They make up about 60% of the total WBC count.
2. Eosinophils
- Function: Eosinophils play a major role in combating parasitic infections and are involved in allergic reactions. They release inflammatory mediators to help control the immune response during allergic reactions.
- Characteristics: These cells are involved in fighting parasitic infections and may help modulate allergic responses.
3. Basophils
- Function: Basophils release histamine during allergic reactions. Histamine enhances blood flow and recruits other immune cells to the affected area, contributing to inflammation.
- Characteristics: Though less common, basophils help mediate allergic responses and are involved in inflammation processes.
Agranulocytes
Agranulocytes do not have visible granules in their cytoplasm but are still very effective in defending the body against infections. The four main types of agranulocytes include:
1. Lymphocytes
Lymphocytes are crucial to the adaptive immune response, which helps the body remember and fight specific pathogens over time. There are three main types of lymphocytes:
- B-Lymphocytes: These cells produce antibodies that target specific pathogens like bacteria and viruses. They are part of the humoral immune response and can provide long-term immunity.
- T-Lymphocytes: T-cells are involved in directly attacking infected or cancerous cells. They also help coordinate the immune response by activating other immune cells.
- Natural Killer Cells (NK Cells): These cells are responsible for attacking and destroying virus-infected cells and cancer cells. NK cells play a vital role in identifying and eliminating abnormal cells.
2. Monocytes
- Function: Monocytes transform into macrophages or dendritic cells once they enter tissues. These cells engulf and destroy pathogens, debris, and dead cells. They also help activate other immune cells by presenting antigens.
- Characteristics: Monocytes are the largest type of white blood cell and play a key role in cleaning up infections and tissue repair.
Summary of White Blood Cell Types and Functions
- Granulocytes (with granules):
- Neutrophils: Engulf and destroy bacteria and fungi.
- Eosinophils: Attack parasites and are involved in allergic reactions.
- Basophils: Release histamine to enhance blood flow and recruit immune cells during allergic reactions.
- Agranulocytes (without granules):
- B-Lymphocytes: Produce antibodies to target specific pathogens.
- T-Lymphocytes: Destroy infected or cancerous cells and coordinate the immune response.
- Natural Killer Cells: Attack virus-infected and cancer cells.
- Monocytes: Transform into macrophages or dendritic cells to clean up debris and help activate other immune cells.
Conclusion
White blood cells are crucial in protecting the body from infections and other harmful organisms. Their diverse types and functions work together to provide a strong defense system, ensuring that the body can respond to infections and injuries effectively. Whether attacking bacteria, fighting viruses, or controlling inflammation, each type of white blood cell plays a specialized role in maintaining health and immunity.
Conditions and Disorders of WBCs
Common conditions and disorders that affect white blood cells?
If you have a low white blood cell count, you might be more likely to get infections (a condition called leukopenia). On the other hand, if your white blood cell count is too high (called leukocytosis), it could mean you have an infection or a serious condition like leukemia, lymphoma, or an immune disorder.
Common signs or symptoms of white blood cell conditions?
Symptoms of white blood cell conditions, where you may have a count that is too high or too low, include:
- Fever, body aches, and chills.
- Wound that is red, swollen, oozes pus, or won’t heal.
- Frequent infections.
- Persistent cough or difficulty breathing.
What is a normal white blood cell count?
It is normal for you to produce nearly 100 billion white blood cells each day. After completing a blood draw, a test counts your white blood cells, which equals number of cells per microliter of blood. The normal white blood cell count ranges between 4,000 and 11,000 cells per microliter.
Common tests to check the number of white blood cells?
Common tests to check the number of white blood cells include:
White Blood Cell Scan: This test is used to detect infections or abscesses in your body’s soft tissues. It involves drawing your blood, separating the white blood cells, and tagging them with a radioactive isotope. After this, the tagged white blood cells are returned to your body, and an imaging test will highlight areas where infections or abscesses may be present.
Complete Blood Count (CBC): This test provides detailed information about the cells in your blood, including both white and red blood cell counts. A healthcare professional will draw your blood, and the lab will analyze it to determine your white blood cell levels.
What causes a low white blood cell count?
A low white blood cell count can be caused by several factors, including:
- Bone marrow failure, such as in aplastic anemia.
- Bone marrow being attacked by cancer cells, like in leukemia.
- Exposure to certain drugs, such as chemotherapy.
- Vitamin deficiency, especially B12.
- HIV/AIDS.
A blood test showing fewer than 4,000 white blood cells per microliter of blood can diagnose a low white blood cell count.
What causes a high white blood cell count?
A high white blood cell count can be caused by several factors, including:
- Autoimmune disorders like lupus or rheumatoid arthritis.
- Viral infections such as mononucleosis.
- Bacterial infections, including sepsis.
- Physical injury or stress.
- Conditions like leukemia or Hodgkin’s disease.
- Allergies.
A blood test showing more than 11,000 white blood cells per microliter of blood can diagnose a high white blood cell count.
Common treatments for white blood cell disorders?
Common treatments for white blood cell disorders depend on the specific condition and how serious it is. Some possible treatments include:
- Taking vitamins to support immune health.
- Using antibiotics to fight infections.
- Surgery to replace or fix damaged bone marrow.
- Receiving a blood transfusion to help increase blood cell levels.
- Undergoing a stem cell transplant to rebuild healthy blood cells.
Major Source: clevelandclinic.org
