Lymphatic System & Immunity

Vocab Lymph: the fluid inside lymph vessels and capillaries The lymphatic system: A collection of cells and biochemicals that aid in filtering and immunity

Lymphatic System Functions Filters blood plasma Launch immune attacks against foreign particles Protects against toxins and cancer

Lymph Nodes Lymph nodes: specialized glands that contain lymphocytes Lymphocytes: found all over the body B and T cells Macrophages that kill microorganisms Lymphatic trunks: collecting ducts for lymph fluid Lymph Modules: the functioning unit of a lymph node Lymph Sinuses: a network of chambers in a lymph node

Lymphatic System Thymus= a soft gland located in the chest that shrinks when you get older Spleen: largest organ in the lymphatic system Contains lymphocytes and macrophages Filters blood as much as lymph nodes do

Lymph Movement Capillaries  vessels  nodes  trunks  ducts Breathing, Exercise and movement increase lymph flow Edema: reduced lymph flow (swelling)

Nonspecific (innate responses) Inflammation= swelling, heat, pain, redness and pus Fever= makes body inhospitable to pathogens Phagocytosis= digests foreign material Chemical barriers= body fluid, stomach acid mechanical barriers= skin, mucus membranes, hair, sweat Species resistance= organism can’t survive in human body Natural killer cells= cells that secrete cytolytic substances that cut through cell membranes

Specific Immune Responses Specific immune response: Specialized cells recognize foreign invaders (slower) Antigens= proteins, sugars or lipids on a cell’s surface recognize foreign invaders

Specific Immunity 2. T cells: requires an antigen on the surface of cells Enter tissues and Kill foreign invaders Have a memory once exposed to a pathogen T cells

Specific Immunity 3. B-cells: activated by antigens or T-cells Have a memory Never enters tissues Produce antibodies

Specific Immunity 4. Antibodies: present in plasma, interstitial fluid, breast milk, tears, bile, stomach acid, mucus, urine Act on invaders 5. Allergic reactions: an immune response to a non- harmful substance that damages healthy tissue Allergens: thing that causes allergic reactions

Specific Immunity 6. Transplant/Tissue Rejection: donor part is recognized as an invader 7. Auto immunity: immune system turning against itself Examples: type 1 diabetes, mellitus, rheumatoid arthritis, lupus

Active Immunity Naturally Acquired: exposure to pathogens stimulates immune response ex: chicken pox Artificially Acquired: a vaccination containing weak or dead pathogens is given to stimulate an immune response ex: polio vaccination

Passive Immunity Naturally Acquired: antibodies passed from mother to fetus through umbilical cord or breast milk Artificially Acquired: antibodies injected into the blood stream