By: Erin Murray, Sachiko Kawata, Michelle Pecora

The lymphatic system is a “specialized component of the circulatory system.” Two main functions- -Immunity -Control the fluid balance in the internal environment Achieves two different kinds of immunity- non-specific, and specific Non-specific- defend against anything that is foreign. Examples of non-specific= specific resistance (genetic by species resistance to certain diseases) medical and chemical barriers (secretion, skin, mucus, sebum, hydrochloric acid, enzymes), phagocytosis (phagocytes ingest and destroy foreign microorganisms), inflammation (tissue damage brings in mediators, which attract white blood cells). Specific- Four different lymphocytes- B cells, make antibodies that attack, or command other cells. Killer T-cells, destroy antigens by attacking them directly. Helper T cells, stimulate the production of anti-bodies by activating B cells. Supressor T cells, turn off antibody production when the infection is gone. The B cells are made and mature in the bone marrow, and all of the T cells are made in the bone marrow and mature in the thymus.

Cells that will grow into the unique types of more specialized cells that circulate throughout the immune system are crated in the bone marrow. This spongy tissue is found in the center shafts of certain long, flat bones of the body. The cells most relevant for understanding vaccines are the lymphocytes, are close to one trillion. The two major classes of lymphocytes are B cells, which grow to maturity in the bone marrow, and T cells, which mature in the thymus. B cells made antibodies that circulate in the blood and lymph streams and connect to foreign antigens to destroy them by other immune cells. Certain T cells can attack and destroy diseased cells they recognize as foreign. T lymphocytes are accountable for cell-mediated immunity. T cells depend on the major histocompatibility complex to help them recognize antigen fragments.

To the right is the diagram of the activation of helper T cells. To the left is activation of B cells to make antibody, and to the activation of cytotoxic T cells.

There are many diseases and problems that can be happening in the Immune System. For example…. Aids/HIV, Allergies, Hodgkin’s Disease, Leukimia, Multiple Myeloma, Lupus, Mononecleosis, Myssthenia Gravis, and White Blood Cell Disorders. There are numerous amounts of sickness in the human body, to say one system.

*AIDS/HIV-there are many mediations that people can take to calm their sickness but at this time, there is stil nocure for this virus. *Allergies-you can take medicine to slow the immune system down, but we can’t cure this problem. *Hodgkin’s Disease and Non-Hodgkin’s Lymphoma-Can be treated with drugs or radiation. *Leukemia-they can take the drugs but only under doctor supervision. * Multiple Myeloma-it can be helped by standard therapy usually *Lupus-mild cases need no treatment but sever cases with aspirin and cortisone. It can’t be cured completely. *Mononecleosis-treated by bed rest and it isn’t fatal. Patients mostly recover within 3-6 weeks. *Myasthenia Gravis-with medication (anticholinesterases or immunosuppressives) *White Blood Cell Disorders-Depends on its cause but sometimes it can recover with nothing at all but if its sever then they must be hospitalized.

Called Lyphoid organs Organs-Tonsils and Adenoids, Lymph Nodes, Appendix, Bone Marrow, Thymus, Spleen, Peyer’s Patches, Lymphatic Vessels, Thoracic Duct, and Lymphatic Vasculature. Tonsils and Adenoids- located in mouth (nose for Adenoids), lymphoid tissue that produce white blood cells that fight against antigens. Prevent infections from nose and mouth.

Lymph nodes- dilations of the lymphatic tissue, supported by reticulin fibers, larger clusters located mainly in axillary (armpit area), and inguinal (pubic area), filters lymphatic fluid. Bone Marrow- located in bones, produces red blood cells that eventually become lymphocytes (T cells mature in the spleen, B cells mature in the marrow). Thymus- located in thoracic cavity just below the neck, mainly used when younger, contains lymphocytes, function is to develop T cells that are immature to T cells that are immune-competent. Spleen- located about mid-body, destroys old red blood cells (waste), and has a good immune response because it filters blood and is able control blood-borne antigens better. Peyer’s Patches- found in small intestine, lymphoid tissues. Lymphatic (Lymph) Vessels- prevent backflow of lymph, contain specialized organs (Lymph Nodes). Thoracic Duct- collects small amounts of interstatial (tissue) fluid and returns it to the blood stream. The larger lymphatic vessels unite into this. Lymphatic Capillaries- closed end tubes, are near normal capillaries, different fluids go in the L. capillaries by osmosis and lymph is then formed.

Gene therapy helps cancer patients. The problem is that the killer T-cells don’t recognize that cancer cells are foreign. Allovectin-2 is injected into the tumor and helps the cells to recognize cancer cells. Cancer vaccine presents the immune system with a harmless version of a pathogen. The immune system learns to recognize cancer if it is presented with a pathogen. It contains similar proteins that are in cancer cells to help the immune system recognize cancer. Immunogene therapy uses the chemicals GM-CSF and B7-2 to build the bodies immune system and destroy cancer cells at the same time. The treatment is a shot of 2 genes in one virus. It can be used as a vaccine or a treatment.

Your Immune System, by Alan E. Nourse, M.D., copyright 1982 The Immune System, by Edward Edelson, copyright system.htm/ system.htm/