The Way the Immune System Works Essay Example

which produces B-lymphocytes (B-cell), immature thymocytes, red blood cells, white blood cells, and platelets. Hematopoiesis is the process wherein hematopoietic stem cells (HSC) differentiate into either lymphoid or myeloid progenitor cells under the influence of growth factors and cytokines produced in hematopoietic tissues. The aforementioned specialized cells all play vital roles in targeting and wiping out foreign antigens. The thymus is an organ that is found in the upper anterior section of the chest cavity just behind the breastbone.

The main function of the thymus, is to produce mature T-lymphocytes, or T-cells. The T-cells play a very important role in the immune system. It is composed of two types of tissues: cortical and medullary. The cortical tissue is an area of intense T-cell development activity. It is where the T-cells develop their antigen receptors. Loss of the thymus, or T-cells, at an early age of life via surgical process or genetic mutation, can result in a severe deficiency of the immune system.

The medullary tissue serves as a staging area where T-cells migrate before they are released into the bloodstream.

The tonsils are gland-like structures on the sides of the throat that carry lymph (the fluid that covers the cells in water and nutrients). Their main function is to help your immune system by catching bacteria and viruses that are passing through your throat. The tonsils located at the back of the throat and under the tongue, contain large numbers of lymphocytes and filter out potentially harmful bacteria that might enter the body via the nose and mouth. Unfortunately, sometimes tonsils don’t perform their job very well, and they can often become a hindrance on

your health.

Treatment for infected tonsils depends on the severity of the infection. In case of acute or mild tonsil infection, one can find relief by practicing some remedies at home, but the course of treatment for chronic tonsillitis can only be decided after thorough physical examination with a sensitivity test. The health care provider examines the inflammation, enlargement and severity of the infected tonsils and decides the basic path of medication. In case of chronic tonsillitis, a strep test or throat culture can be collected in order to determine the exact cause behind the infection.

Blood tests and biopsy can be required in some rare cases. The spleen is a flattened organ located in the upper left portion of the abdomen.

The spleen serves as an immunologic blood filter. It filters your blood and it destroys old or damaged blood vessels. It is made up of B-cells (B-lymphocytes), T-cells (T-lymphocytes), dendritic cells, and macrophages. The purpose of the T-cells and B-cells, is to identify the foreign particles and create antibodies against it.

The lymph nodes are small, roundlike, bean shaped organs located in the lymphatic vessels. The lymph nodes function as an immunologic filter for the body.

It filters particulate and soluble molecules out of lymph, thus attracting immunogens for immune system stimulation. Lymph is the interstitial tissue fluid picked up by the lymphatics for transport to the lymph ducts that empty into the veins.

Lymph nodes are also composed mostly of T-cells, B-cells, dendritic cells and macrophages. When foreign antigens enter the lymph nodes by either lymphatic vessels, or by circulation, these cells identify them as foreign antigens and respond accordingly. Cells of

the Immune System Two types of cells exist in the immune system: myeloid cells and lymphoid cells.

There are four types of myeloid cells. They are granulocytes, monocytes, macrophages, and dendritic cells.

Granulocytes are leukocytes (white blood cells) containing granules in the cytoplasm. They act as a first line of defense, rushing toward an infected area to capture offending microbes. These cells kill microbes by digesting them with killer enzymes contained in small units called lysosomes. Macrophages act as effector cells in cell mediated immunity.

Dendritic cells are mostly found in the skin and mucosal epithelium. Unlike macrophages, dendritic cells can also recognize viral particles that are unlike themselves.

Lymphoid cells are the second type of cell in the immune system and these cells are responsible for immune responses. The lymphoid cells are composed of B lymphocytes (B-cells), T lymphocytes (T-cells), and natural killer cells.

B-lymphocytes spend the earlier stages of life in the bone marrow. Their job is to travel through the blood and lymph searching for antigens which they can interlock with. Once a B-cell has found an antigen, it starts duplicating itself. These cloned cells mature into antibody creating plasma cells.

T-lyphocytes travel through the blood and lymph looking for antigens.

When an antigen is located, they notify other cells to help in combating the invader. Natural killer cells play a major role in the destruction of tumors and cells infected by viruses. They kill cells by releasing small amounts of proteins called perforin and granzyme that cause the target cell to die. Types of Immune Responses We as humans are capable of two kinds of immune responses, innate and adaptive.

Both

the innate and immune responses distinguish between self and non-self antigens, but the degree of specificity underlying the recognition of the foreign entity, are very different.

The innate response has two components: a collection of physical, chemical, and molecular barriers, and an army of cells possessing receptors that recognize a limited number of molecular patterns common to a wide variety of pathogens. The adaptive response requires recognition and effector actions that are highly specific to the precise foreign entity that has triggered the response. Immunity Disorders in Humans Autoimmunity takes place when immune responses mounted in the host are directed against self-components.

Autoimmune diseases are pathophysiological stages wherein the hosts’ own tissues are damaged as a result of the immune system attacks.

In other words, the body will actually attack itself. The immune system mistakes some part of the body as a pathogen and attacks it. Autoimmune disorders fall into two general types: those that damage many organs and those where only a single organ or tissue is directly damaged by the autoimmune process. Many parts of the body such as the red blood cells, blood vessels, connective tissues, digestive system, endocrine system, muscles, joints, nerves and skin may be affected.

Autoimmune diseases predominantly affect women, frequently during their childbearing years.

These diseases often tend to be hereditary, and certain environmental factors may also contribute to a weakened immune system. Some examples of autoimmune diseases are Crohn’s disease, Graves’ disease, Multiple schlerosis, and Rheumatoid arthritis. The cause of autoimmune disease is unknown, but it is proven that there is an inherited predisposition to develop autoimmune disease in many cases.

In a few types of autoimmune

diseases, a bacteria or virus triggers an immune response, and the antibodies or T-cells attack normal cells because they have some part of their structure that resembles a part of the structure of the infecting microorganism. Most autoimmune diseases cannot be cured, although much can be done to relieve symptoms and improve quality of life.

The treatment of an autoimmune disease depends on the symptoms associated with a specific disease. There are various treatment options such as conventional medicine, complementary therapy, or natural remedies that can help to reduce the severity of symptoms. .