Immune+System

= Immune System =

Functions
The immune system is the part of our body that keeps our bodies healthy.The immune system protects the body from bacterial, parasitic, fungal, viral infections and from the growth of tumor cells. Many of these cell types have special functions. The cells of the immune system can kill parasites or tumor cells, or kill viral-infected cells. It consists of two levels of protection, the non-specific defenses and the specific defenses. The non-specific defenses, such as the skin and mucous membranes, prevent microorganisms from entering the body.

Major Organs
There are are four main organs in the immune system: bone marrow, thymus, the spleen and lymph nodes. All the cells of the immune system are initially derived from the bone marrow; bone marrow is the soft tissue found in the hollow interior of bones. There are two types of bone marrow: red bone marrow and yellow bone marrow. Red blood cells, platelets and most white blood cells arise in red marrow; some white blood cells develop in yellow marrow. A Thymus is a flat organ situated above the heart and below the thyroid gland. Each lobe is surrounded by a capsule and is divided into lobules, which are separated from each other by strands of connective tissue. Each lobule is organized into two compartments: the cortex (outer compartment) the medulla (inner compartment). The spleen is a filter of blood. The spleen removes foreign materials away from the blood and it destroys old red blood cells.

How it works
Inside your body there is an amazing protection mechanism called the immune system. It is designed to defend you against millions of bacteria, microbes, viruses, toxins and parasites that would love to invade your body.The immune system, which is made up of special cells, proteins, tissues, and organs, defends people against germs and microorganisms every day. In most cases, the immune system does a great job of keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection. One of the illness’s, Autoimmune, is caused when when the cells in your body attack each other. When your body fights a disease it uses its white blood cells to attack the disease. This part inside the body is one of the most important to keep your body healthy and fit.

How it works with other body systems (at least three other systems)
Two of the main fluid systems in the body are blood and lymph. They are intertwined throughout the body and they are responsible for transporting the agents of the Immune System. The immune system plays a role in all the other systems by having special cells, leukocytes, that can attack foreign matter, like bacteria and viruses. The immune system works well with the integumentary system because the skin is the first defense against pathogens.

Disorders of the immune system
Disorders in the immune system can cause disease. Immunodeficiency diseases occur when the immune system is less active than normal, resulting in recurring and life-threatening infections. Another disorder is when the body's own immune system attacks is own tissue as a foreign matter, this is called autoimmune.The proper targets of your immune system are infectious organisms--bacteria such as these streptococci; fungi, parasites, including worm-like microbes that cause malaria; and viruses such as this SARS virus. Cancers of the immune system can always harm the immune system. Another type of disorder is allergic disorders which the immune system overreacts in response to an antigen. http://uhaweb.hartford.edu/bugl/immune.htm

http://encarta.msn.com/encyclopedia_761566336/Lymphatic_System.html http://www.encyclopedia.com/doc/1E1-lymphati.html [|en.wikipedia.org/wiki/Immune_system] http://www.kidshealth.org/parent/general/body_basics/immune.htmll