Karteikarten
Body Defencees
Karten in diesem Stapel (19)
- 1Body Defenses – Lines of Defense The body has two defense systems for removal of foreign substance (antigens)
- Non-specific (Innate)(1 and 2)
Protects against anything foreign to the body Responds immediately
- Specific (adaptive immune system)(3)
Against particular foreign substances
Needs to be primed by initial exposure to antigen - 2First Line (Innate) a The skin
Physical barrier to foreign materials
pH of the skin is acidic to inhibit bacterial growth
Sebum is toxic to bacteria
Keratin blocks entry of foreign matter - 3First Line (Innate) b- Stomach mucosa
Secretes hydrochloric acid
Has protein-digesting enzymes
- Saliva and lacrimal fluid contain lysozyme
- Mucus traps microogranisms in digestive and respiratory pathways - 42nd Line (Innate) a- Phagocytes (neutrophils and macrophages)
Engulfs foreign material into a vacuole
Enzymes from lysosomes digest the material - 52nd Line (Innate) b
Natural killer cells
Can lyse and kill cancer cells
Can destroy virus- infected cells
Not phagocytic
Chemical attack - perforins - 6Inflammatory Response - 2nd line (innate) Triggered when body tissues are injured
Produces four cardinal sign
Redness
Heat
Swelling Pain
Results in a chain of events leading to protection and healing - 7Inflammation - 2nd line (innate) Increased blood flow to the area - hyperemia
Brings more oxygen and nutrients for repair
Brings white blood cells to the area
Brings clotting proteins to the area to contain injury Disposes of cell debris and pathogens
Sets the stage for repair - 8Body Defenses Fever
Abnormally high body temp
Systemic response to invading antigens
WBC and macrophages secrete “pyrogens” Benefits the body – disadvantages bacteria - 9Body Defenses - 3rd Line (Adaptive)- Involves specific B and T lymphocytes
- Antigen specific – recognizes and acts against particular foreign substances
- Systemic – not restricted to the initial infection site
- Has memory – recognizes and mounts a stronger attack on previously encountered pathogens - 10Types of Immunity- Humoral immunity – B cells
Antibody-mediated immunity
Targets antigens free in body fluids
- Cellular immunity – T cells
Cell-mediated immunity
Cells target virus infected cells (antigen inside cell) - 11Antigen Substance able to provoke an immune response
Non self
Antigenic – cell surface
contains foreign molecules
Self – antigens – recognise our own antigens – no immune response - 12Humoral (Antibody-Mediated) Immune Response B lymphocytes with specific receptors bind to a specific antigen
The binding event activates the lymphocyte to undergo clonal selection
A large number of clones are produced (primary humoral response) - 13Humoral (Antibody Mediated) Immune Response- Most B cells become plasma cells
Produce antibodies to destroy antigens Activity lasts for four or five days
- Some B cells become long-lived memory cells (secondary humoral response) - 14Secondary Response Memory cells are long-lived
A second exposure causes a rapid response
The secondary response is stronger and longer lasting - 15Active Immunity Your B cells encounter antigens and produce antibodies and memory cells
Active immunity can be naturally or artificially acquired - 16Passive Immunity- Antibodies are obtained from someone else Conferred naturally from a mother to her fetus Injection of antibodies e.g. antivenom
- Memory cells not produced
- Protection provided by “borrowed antibodies” - short term - 17Cellular (Cell-Mediated) Immune Response Antigens must be presented by macrophages to T cell (antigen presentation)
T cells bind to presented antigen
After antigen binding, clones form as with B cells, but different classes of cells are produced - 18T Cell Clones Cytotoxic T cells
Specialize in killing infected cells Insert a toxic chemical (perforin)
Helper T cells
Recruit other cells to fight the invaders Interact directly with B cells - 19T Cell Clones b Regulatory T cells
Release chemicals to suppress the activity of T and B cells
Stop the immune response to prevent uncontrolled activity or autoimmune disease
A few members of each clone are memory cells
Informationen
- Beschreibung
- 5 HAP 1 Karteikarten am Body Defencees, erstellt von Jonathan Cash am 17/10/2015.
- Erstellt von
- Jonathan Cash
- Aufrufe
- 6
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