Human Immune System Created by: Bryan Bencomo, Allan Jones, and Tim Hoskinson

What Does it Do? Two most important functions –Maintenance of fluid balance in the internal environment. –Immunity Without the lymphatic system, a small amount of interstitial fluid is left behind, causing tissue destruction or death

Lymph A clear Watery fluid that flows through lymphatic vessels It is essential for the removal of wastes throughout the body After flowing through the lymph vessels, the lymph gets dumped into an artery or vein Anatomy

Lymph Nodes –oval-shaped or bean-shaped structures –Some are as small as a pinhead and others as large as a lima bean –When an infection is present, germinal centers form and the node begins to release lymphocytes –The center or medulla of a lymph node is composed of sinuses and cords. The spleen is an organ which is really like a giant lymph node filled with blood.

Lymph Vessels Lymphatic vessels resemble veins in structure with these exceptions: –Lymphatics have thinner walls. –Lymphatics contain more valves. –Lymphatics contain lymph nodes located at certain intervals along their course. Proteins that accumulate in the interstitial spaces can return to the blood only via lymphatics

White Blood Cells “Killer” T-Cell –Sensitized T-cells that release lymphotoxin, a powerful poison, are called killer T-cells “Helper” T-Cell Creates –Cytotoxic T lymphocytes (CTL), which destroy specific infected cells, –B-cells, which produce antibodies –Natural killer cells, which destroy any infected cells –Production of antibodies and cytokines

Thymus It is composed of two pyramid shaped lobes Serves as a final site of lymphocyte development before birth. Soon after birth the thymus begins secreting a group of hormones collectively called thymosin that enable lymphocytes to develop into mature T-cells

Inherited Immunity –immunity to certain diseases develops before birth Natural immunity- Exposure to the causative agent is not deliberate –Active (exposure) A child develops measles and acquires an immunity to subsequent infection –Passive (exposure) A fetus receives protection from the mother through the placenta, or an infant receives protection by way of the mother's milk Artificial Immunity- exposure is deliberate –Active injection of the causative agent, such as vaccination against polio, confers immunity –Passive injection of protective material (antibodies) that was developed by another individual's immune system Immunity

AIDS Acquired Immunodeficiency Syndrome –Caused by the HIV Virus –Damaging white blood cells, the virus stops the human immune system from functioning –It can be spread by having contact with body fluids and other ways –Eventually the immune system breaks down since no white blood cells can identify any disease/virus –The person eventually dies from an opportunistic disease; there is no treatment Antibody Animation!!

Hodgkin’s Disease Is a lymphoma, type of cancer that develops in the lymphatic system Basically, cells in the body divide too quickly and a mass of extra tissue is formed This prevents the immune system from functioning properly Symptoms include: Swelling in lymph nodes, fevers, night sweats, and weight loss Treatment includes chemotherapy and radiation therapy, but there is no “cure”.

New Technology Advancements in the biotechnology sector have led to many medical breakthroughs over the last few years Medicines such as Proleukin which helps goad the body’s immune system were science fiction as little as 15 yrs. Ago New technology is now available which shuts off the disease-causing messages the gene sends to the body More is in the future though, such as a cure for AIDS and other so far “incurable” diseases

Bibliography BBC Health- The Washington Post-Jan. 08, 2002 “Human Genome Sciences to Begin Tests of Cancer Drug” Encarta Encyclopedia UCLA University Wire “Scientists testing HIV vaccines at UCLA” All About You, Raymond V. Hand Jr. Funk & Wagnalls’ New Encyclopedia The Human Body, Charles Clayman The Human Body: An Overview, Mary Kittredge