Lymphatic System & Immunity. Vocab -gen: be produced Humor-: fluid Nod-: knot Immun-: free Inflamm-:...
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Transcript of Lymphatic System & Immunity. Vocab -gen: be produced Humor-: fluid Nod-: knot Immun-: free Inflamm-:...
Vocab
• -gen: be produced• Humor-: fluid• Nod-: knot• Immun-: free• Inflamm-: set on fire• Patho-: disease• Lymph: the fluid inside lymph vessels and
capillaries
Lymphatic System
• The lymphatic system: A collection of cells and biochemicals that travel through lymph vessels, organs and glands
Functions
• Launch immune attacks against foreign particles• Protects against toxins and cancer• Filters blood plasma
Pathways
• Begin at capillaries and merge with larger vessels• Capillaries → Vessels → lymph nodes → lymph
trunks → ducts
Lymph Nodes
• Lymph nodes: specialized glands that contain lymphocytes• B & T cells of the immune system• Macrophages that kill microorganisms
• found all over the body except in the nervous system• Functions:• Filters harmful particles from lymph• Immune surveillance= lymphocytes attack viruses,
bacteria and parasites
Lymphatic System
• Hilum- where blood vessels and nerves join a lymph node• Lymphatic trunks: collecting ducts that receives
lymph fluid from distal parts of the body
Lymphatic System
• Lymph Modules: the functioning unit of a lymph node• Lymph Sinuses: a network of chambers in a lymph
node
Lymph Movement
• One way • Exercise and movement increase lymph flow• Breathing stimulates lymph movement• Impaired lymph movement: Causes edema
(swelling)
Lymphatic System
• Thymus= a soft gland located posterior to the sternum• Large when you are born – shrinks when you get older• Secretes lymphocytes and hormones
Spleen
• The largest organ in the lymphatic system• Filled with blood vessels, not lymph• Contains lymphocytes and macrophages• Filters blood as much as lymph nodes do
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, (low pH)• mechanical barriers= skin, mucus membranes, hair,
sweat• Species resistance= organism can’t survive in human
body• Natural killer cells= cells that secrete cytolytic (“cell
cutting”) substances that cut through cell membranes
Specific Immune Responses • Specialized cells recognize foreign invaders• Respond more slowly than non-specific responses• Antigens= proteins, sugars or lipids on a cell’s
surface recognize foreign invaders
Lymphocytes
• T cells: require antigen-presenting cells to be activated• Enter tissues and Kill foreign invaders• Have a memory once exposed to a pathogen
Lymphocytes
• B-cells: activated by specific antigens or T-cells• Have a memory once exposed to a pathogen• Never enters tissues• Produce antibodies
Antibodies
• Immunoglobins: present in plasma, interstitial fluid, breast milk, tears, bile, stomach acid, nasal mucus, urine• Act on allergens, bacteria, viruses, fungus and toxins
• Reaction to antigens: • Tries to contain the pathogen or toxin to the area it
is in• direct attack, stimulate inflammation, or activate
cells to act
Allergic Reactions
• Allergic reactions: an immune response to a non-harmful substance• can damage tissues
• Allergens: antigens that cause allergic reactions
Allergic Reactions
• Immediate-reaction allergies: within minutes of contact with allergen• Activates B-cells• Release histamines and prostaglandins that:• Causes blood vessel dilation• Swelling• Increased mucus production• Contraction of bronchial muscles
Transport/Tissue Rejection
• Transplant/Tissue Rejection: donor part is recognized as an invader and the body reject it• Immunosuppressive drugs: used to reduce the
chance of tissue rejection• Interfere with immune response by suppressing T-cells
and antibody formation
Auto Immunity
• Auto immunity: immune system turning against itself• Autoantibodies: attack tissues and organs• Examples: type 1 diabetes, mellitus, rheumatoid
arthritis, lupus• Caused by:
• Viruses• T-cells not “learning” to recognize other threats• Genetics
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