Every empire needs gallant soldiers to keep their cities from invasion and if peradventure invaded needs soldiers to suppress intruder’s proliferation. Immunology is the study of the immune system, it deals with how the natural body soldiers help to fight and eliminate intruders (microorganisms) that causes diseases in our body.
The human body is composed of many systems: circulatory system, digestive system, nervous system, respiratory system together with the immune system.
A body system is composed of the organs performing similar functions, organs are composed of tissues while tissues are made up of cells carrying out similar functions.
For the sake of easy understanding, the following sub-topics will be explained
- Immune organs
- Immune tissues
- Immune cells
The organs producing white blood cells in the human body are also referred to as primary lymphoid organs.
Examples of such these organs include:
- Bone marrow
All blood cells (both white and red blood cells) are produced in the bone marrow. An important type of white blood cell are the lymphocytes. Examples of lymphocytes are B-cells and T-cells which are produced in the bone marrow. After the production of T-cells in the bone marrow, they migrate to the thymus for maturation. Thymus is located in the upper anterior front part of our chest, between our lungs while the bone marrow is a soft reddish substance found in the hollow of the bone. B-cells are that are also produced in the bone marrow matures in the bone marrow. This marks the major difference between the T- Cells and the B-cells coupled with the fact that T-cells receptors only recognize antigens on viral-infected body cells while B-cells receptor sites recognize both bacterial and viral antigens on the surface of body cells.
White blood cells are stored and activated in the lymphatic tissues. Examples of such tissues include: appendix, lymph node, tonsil and adenoids, spleen and Peyer’s patches tissues.
The Peyer’s patch is found in the lowest portion of the small intestine (in the jejunum, ileum and duodenum). It stores the lymphocytes that fight against pathogenic microorganisms entering into the intestine.
Tonsils and adenoids are located at the back of our throat. They are round lumps of tissue that can be seen when one opens one’s mouth white blood cells are stored in this tissue, tonsil and adenoid help to trap and eliminate bacteria and viruses entering the body through the mouth and nose before they can reach the other parts of the body.
The lymph node is another major site for the storage of white blood cells. It found all above the body. they act as filter for foreign particles and cancer cells. It is believed that immune cells present in the appendix protect the beneficial gut bacterial for it serves as a reservoir for beneficial gut bacteria.
Immune cells are of five types: neutrophils, eosinophils, basophils, lymphocytes, and monocytes
Eosinophils are known for primarily fighting intestinal parasites such as flatworm and roundworm.
Example of neutrophils are phagocytes that move toward intruding bacteria and ingest them. See phagocytosis
Basophils, on the other hand, are found at the cite of body ectoparasite (e.g. tick) They fight against ectoparasite and help in their elimination in our body.
Monocytes, on the other hand, recognizes pathogens using the complement system follower by subsequent phagocytosis.
Lymphocytes include the T-cells, B-cells, and Natural killer cells (NK-cells)
This is referred to as the dysfunction of the immune system. Thereby leading to the inability of the body to fight off infections. This can be genetic in case of hypogammaglobulinemia, a decrease of one or more types of antibodies within an individual thus leading to continuous predisposition of such individual to mild respiratory infections, and agammaglobulinemia, a condition of lack of all or most antibody thereby leading to continuous susceptibility of individual to infections.
Immunodeficiency can also be caused by viral infection(HIV/AIDS) that leads to T-cell deficiency and Age (the number of immune cells produced in the body decreases with age).
How to improve our immune systems
Immune system functions in our body can be improved by avoiding tobacco intake, taking diet high in fruits and vegetables, regular exercise, avoiding excessive intake of alcohol, and getting adequate rest as well as good personal hygiene.