Immunity & other Body Systems

               A new kind of researches is trying  to explore how the immune system and the brain may have a role to influence health. Biological links between the immune system and the central nervous system ( C.N.S) exist at several levels. Beside that to help a person respond to emergencies by mobilizing the body's energy, reserves  these decrease antibodies and reduce lymphocytes  in both their strength beside their number. 
 
           Recently, it has been well known that hormones and neuropeptides, which convey messages to different cells in the nervous system and organs throughout the body, also they can speak to cells of the immune system. Some of the macrophages and activated lymphocytes actually manufacture typical neuropeptides.
Hormones produced by the thymus act on cells in the brain. The brain may directly influence the immune system by sending messages down nerve cells. Nerve fibers have been found that they have been connected to the thymus gland, lymph node, spleen, and bone marrow. Immune cells may function in a sensory capacity detecting the arrival of foreign invaders and replaying chemical signals to alert the brain. 

       The lymphatic system is composed of lymph vessels, lymph nodes, and organs. These organs include the bone marrow, the spleen, and the thymus. The lymphatic system functions to:

    Lymphatic System in Action

         Lymph nodes are part of a network of lymph vessels that extends throughout your body. The clear yellow fluid  that flows through the lymphatic vessels is called lymph . Lymph travels through your body to a location near your shoulders, where it drains into your circulatory systems. During its journey, lymph is filtered through lymph nodes, where bacteria and viruses  can be trapped.  These nodes are filled with white blood cells called lymphocytes. Lymphocytes fight infections, when  viruses are present, the lymphocytes multiply  rapidly and the lymph nodes are tender and swollen. Along  the lymphatic vessels are special areas, where lymphocytes can     
be recruited, mobilized, and 
deployed to appropriate sites
 as part of the immune response,
 these sites  include the lymph
 nodes , tonsils, bone marrow,
 spleen, liver, lungs and intestines. 

                                                        From The Merck Manual of Medical information-Home Edition ,Chapter 167, edited 
by Mark H. Beers and Robert Berkow.
Copyright 1997 by Merck  &Co., INC., 
Whitehouse Station, NJ.  

      Did you know that you can see  the lymphatic system  at work when you are sick. Sore lumps in your neck are noticed when you are sick . These little lumps are swollen lymph nodes that are helping  you get well. You can also see this system at work when a throats infection causes the lymph  nodes under the jaw to swell or when a wound in your fingertip leads to an enlarged lymph node at the elbow .Lymph nodes actually swell, because the lymphatic vessels drain the infection by carrying it to the nearest area where an immune response can be organized.