Presentation on theme: "Lymphatic System By Jenna Hanson and Rachel Gaddis."— Presentation transcript:
Lymphatic System By Jenna Hanson and Rachel Gaddis
Word Bank: tonsils spleen thymus lymph node Lymph vessels
What is the lymphatic system? The lymphatic system is a collection of cells and biochemicals that travel in lymphatic vessels, and the organs and glands that produce them. The lymphatic system is also known as the immune system.
What does the lymphatic system do? Transports fluids Carries away excess fluid from interstitial spaces Destroys foreign particles (Immunities) Destroys toxins and cancerous cells
Lymphocytes Type of white blood cell (leukocyte) Two types: T-cells and B-cells Determines immune response *Lymphocytes must be activated in order to respond to antigens!*
Lymph Nodes Contain large numbers of lymphocytes and macrophages that fight invading organisms Vary in diameter from 1/25 to 1 inch Located along lymphatic vessels Approximately 500-700 lymph nodes in the adult human body
Lymphatic Pathways Prevent backflow of lymph Begin as lymphatic capillaries Turn into larger lymphatic vessels
Functions of the spleen Filters blood (immune system) Helps to fight certain kinds of bacteria Recycles red blood cells
Thymus (Thoracic Cavity, between lungs, connects w/ trachea )
Functions of the thymus Transform lymphocytes into T-cells T-cells in the thymus help to fight disease and infection *The thymus grows less functional with age and is eventually replaced almost entirely by adipose (fat) tissue*
Body Defenses Innate (nonspecific) Species resistant: the development of diseases unique to that organism. Mechanical barriers: Prevent entry of infectious agents, in areas such as the respiratory, urinary and reproductive systems (Skin and mucus membranes, and sweat). Chemical barriers: Enzymes in body fluid that provide the barrier to the pathogens. Lymphocytes produce hormone like peptides called interferons. (Viruses/ tumor cells). Fever: the raise in temperature cause the spleen and liver to take away iron in the blood which is needed for bacteria/fungi as the temp rises. Inflammation: blood flow to region of infection increases to isolate and destroy the infection, however this is painful
Body defenses cont. Adaptive (Specific)/ Immunity Antigens: Usually located on cells surface; with the help of lymphocytes detect foreign antigens. Lymphocyte Origins: During fetal development, release lymphocytes into the circulation with later turn to T and B cells.
Types of antibodies Immunoglobulin G (IgG): in plasma and tissue fluids, effective against bacteria, viruses and toxins. Immunoglobulin A (IgA): Found in exocrine gland secretions (breast milk, tears, nasal fluid, gastric juices, intestinal juice, bile and urine). Immunoglobulin M (IgM): Develops in blood plasma in response to contact with certain antigens in food or bacteria. Immunoglobulin D (IgD): Found on surface of most B cells. Important in activating B cells. Immunoglobulin E (IgE): Found in exocrine secretions. Associated with allergic reactions.
Immune Responses Primary response: Cells release antibodies (IgM, then IgG) Antibodies are then transported to blood and throughout body Secondary response: Following a PR, B cells produce a ‘memory’ cell. More vigorous of a response than PR.
Autoimmune responses Sometimes, the immune system accidentally produces autoantibodies, T cells that attack and damage tissues and organs. The condition of cells attacking oneself is called autoimmunity Common auto immune disorders Type 1 Diabetes Rheumatoid arthritis Lupus
Allergic Reactions Allergic responses are immune attacks against a non-harmful substance Allergic reactions can vary from inflammation and fever to the closing of the throat, resulting in inability to breathe. Common allergens: Peanuts Grass Dairy (Lactose intolerance) Shellfish
Diseases Multiple Sclerosis (MS): Causes pain, blindness, weakness, poor coordination, and muscle spasms Immune system destroys myelin sheaths in neurons, damaging nerve tissue Can be suppressed but no treatment AIDS: Acquired Immune Deficiency Syndrome. Virus that weakens the immune system Final stage of HIV Often Flu like symptoms Life-threatening Transmitted through sexual intercourse, contaminated needles, birth and receiving infected blood (transfusion) No treatment