White and red blood cells, or WBCs and RBCs, are created in the bone marrow and lymphatic tissue. Red blood cells are called erythrocytes, while white blood cells are referred to as leukocytes. Both types of blood cell travel throughout the body using an intricate network of passageways known as the circulatory system. Blood cells are suspended in a liquid called plasma, which carries the cells to their destinations. Though they share a common anatomical environment, white blood cells have a distinctly different purpose from red blood cells.
Function
Red blood cells supply muscles and organs with oxygen, and white blood cells fight infection. Gary Thibodeau, author of "The Human Body in Health and Disease" explains that when the body is threatened by foreign agents such as bacteria, viruses or allergens, the immune system produces greater amounts of white blood cells.
Thibodeau states that a disease response can alter the proportions of white blood cell types in relationship to each other. For example, mononucleosis causes an increase in lymphocytes and monocytes, while parasite infestations prompt an increase in eosinophils.
Types
There are five types of leukocytes, which are divided into two classes, according to RNCeus. Granulocytes are white blood cells that contain granules within their cytoplasm. Neutrophils, eosinophils and basophils are granulocytes. White blood cells with no granules are called nongranulocytes. This class includes lymphocytes and monocytes.
Neutrophils and monocytes fight infection through similar methods, by engulfing invasive microorganisms and digesting them. Lymphocytes act by forming antibodies that restrict the activity of viral microbes. Eosinophils and basophils help secrete blood-clotting agents and protect against allergens.
Disorders
Various disorders can increase or decrease the white blood cell count and can affect each type of white blood cell differently. Leukopenia is an abnormal deficiency in white blood cells. This can occur when a person has an immune disorder such as AIDS. Leukocytosis is an increase in white blood cells. Leukemia is a malignant disease that causes an extreme rise in white blood cell levels.
Effects
Leukopenia can cause a person to be dangerously vulnerable to contracting diseases that she cannot fight off because of a deficit in the immune system's primary line of defense, the white blood cells.
Leukocytosis caused by leukemia can result in common symptoms such as fever, fatigue, tendency to bleed or bruise easily, bone pain and excessive sweatiness, according to MayoClinic.com.
Considerations
Exposure to drugs and chemicals can influence white blood cell counts. The Arizona Telemedicine Program notes that penicillin, chemotherapy and radiation treatments can all cause neutropenia, a type of leukopenia in which neutrophil levels are decreased. Dietary deficiencies and alcoholism can also influence neutrophil counts.
An increase in leukocyte production can be caused by the use of steroid medications, as well as the influence of certain environmental and emotional factors such as cold, heat, pain and anger.
References
- RNCeus: White Blood Cell Count
- MayoClinic.com: ALeukemia: Symptoms
- niversity of Arizona: Telemedicine: Benign Disorders
- The Human Body in Health and Disease; Gary Thibodeau, PhD and Kevin Patton, PhD; 2002
