The human immune system is a complex combination of organs, cells and physiological responses that work together to keep bodies free from disease, bacteria and infection. When the immune system or any of its parts are compromised due to an existing infection or birth defect, an individual may suffer from increased illnesses or become vulnerable to internal corruptions such as cancers or other malignant growths.
White Blood Cells
The smallest parts of the immune system are the myriad types of white blood cells that are responsible for demolishing malicious bacterial, viral and tumor cells. T cells serve as both managers and infection killers. They are responsible for activating and communicating with other types of white blood cells before destroying malignant cells like parasites and tumors. Natural killer cells directly attack virus cells and tumor cells such as lymphoma, melanoma and herpes. They work alone without communicating with other parts of the immune system. B cells work to produce antibodies that attach themselves to foreign cells as a sign to natural killer cells and T cells to attack and destroy.
Bone Marrow
An essential aspect of the immune system--and the origin of all types of immune system cells--is red bone marrow. Bone marrow is a specific type of tissue that grows in the empty centers of bones. This tissue uses the process of hematopoiesis to manipulate its own stem cells into B cells and natural killer cells, as well as the foundational pieces of other immune cells like T cells. Once they are created, these cells migrate out of the marrow tissue and circulate through the blood stream to infection sites, other glands or around the body as general patrol entities.
Thymus Gland
The foundations of T cells produced in the bone marrow, called thymocytes, leave the tissue and travel to the thymus gland for completion. The thymus is a small gland located near the lungs in the upper torso. Thymocytes complete their maturation in the thymus through the process of thymic education, where each cell is developed and examined for maximum efficiency. Cells that are not strong enough to provide immune support are destroyed and absorbed by the thymus, while the successfully matured cells are excreted from the gland into the blood stream.
Spleen
The spleen, which is located on the left side of the abdomen just under the lung, is a blood filter that works to remove malignant cells from the blood stream. To assist in this function, it holds a significant store of B cells, T cells and natural killer cells to help eliminate any contaminants that are caught. The spleen also assists in immune function by holding a store of red blood cells and platelets that can be deployed as support for the immune cells in the event of an infection or wound.
Lymph Nodes
Lymph nodes, found throughout the body, are also integral parts of the immune system that filter tissue fluid for bacteria cells, tumor cells and viral particles. Like the spleen, lymph nodes are full of the various types of white blood cells that clean the lymph fluid before returning it to various areas of the body. Lymph nodes are located in the head, neck, arms, legs, abdomen and genital area of the human body and are connected through a network of afferent lymphatic vessels. In the event of an infection, white blood cells can use these lymphatic vessels to quickly communicate with other parts of the immune system.
Tags: immune system, blood cells, killer cells, parts immune system, white blood