Immune System Flashcards
Inflammatory Response
- nonspecific immunity
- heat, redness, pain, swelling
- by increased blood flow and vascular permeability
- helps phagocytic WBCs reach area
Nonspecific Immunity
- aka innate immunity
- attack any irritant that threatens internal environment
- general protection
- skin and mucous membranes, tears and mucus
- phagocytosis of bacteria by WBC
- more rapid than specific immunity
Specific Immunity
- aka adaptive immunity
- specific protection
- selective
- 2nd exposure
- no serious symptoms, organism quickly destroyed
- slow compared to nonspecific
Types of Specific Immunity
Natural-not deliberate, occurs in everyday exposure
Artificial-immunization, deliberate exposure
Active-individual’s own immune system responds to harm
-natural or artificial
Passive-immunity to individual not previously immune
-temporary and provides immediate protection
Antibodies
- protein compounds normally present in body
- combining sites–>concave regions on surface
- ability to combine with antigen
Antigen
-compounds with molecules with small regions on surfaces uniquely shaped to fit combining sites of specific antibody
Antibody Function
- antibodies produce humoral (antibody-mediated) immunity
- antibody binds to specific antigen and makes it harmless
- by neutralizing or agglutination
- then destroyed through phagocytosis
- antibody binds to specific antigen and makes it harmless
Complement Cascade
- when antigen and antibody form complex, expose 2 regions
- complement-binding sites
- permits complement proteins to initiate series of event to kill cell
Complement Proteins
- group of protein enzymes, usually inactive in blood
- activated by exposure of complement-binding sites
- specialized proteins that target foreign cells for destruction
- end result of complement cascade
- doughnut-shaped protein rings formed
- bore holes in foreign cell and cell bursts due to pressure
- attract immune cells to infection site
- activate immune cells
- mark foreign cells for destruction
- increase permeability of blood vessels
Phagocytes
- antibodies ‘flag’ foreign material to alert phagocyte
- neutrophils–>migrate out of blood, short-lived, pus mostly dead
- monocytes–>migrate out of blood, dev. into macrophages
- macrophages–>’wander’ to engulf found bacteria
- dendritic cell (DC)-help protect
Antigen-Presenting Cells (APCs)
- macrophages and DCs
- ingest a cell, remove antigen and display it on cell surface
- triggers immune responses in other immune cells
Lymphocytes
- responsible for antibody production
- continually patrol, searching out enemy cells
- circulate in body’s fluids
- most numerous cells of immune system
B Lymphocytes-Development
1) Transformation of stem cells into immature B cells
- in liver and bone marrow (only bone in adults)
- mature and leave tissue
- enter blood and transported by blood to lymph node
2) B Cell Activated
- when comes into contact with specific antigen
- divides rapidly to create clones
- plasma cells–>effector, secrete lg. # of antibody into blood
- memory cells-secrete antibodies, not immediately
- remain in lymph until contact with antigen
B Lymphocytes-Function
- indirectly produce humoral immunity
- plasma cells are antibody factories of body
- formed on ER
- the more antibodies, the more antigens neutralized
T Lymphocytes-Development
1) In Thymus Gland
- stem cells from bone marrow to thymus
- then migrate to lymph nodes
2) Contact with antigen
- binds and activates and creates clones
- effector cells–>actively engage in immune response
- memory cells
- don’t engage
- produce additional clones including more effector T cells
T Lymphocytes-Function
Cell-Mediated Immunity
-resistance to disease from action of cells
Cytotoxic T Cells
- kill infected cells and tumour cells directly
- release lethal poison when bound to antigen
Helper T Cells
-indirectly attack by releasing compounds in area and attracting macrophages
Regulatory T Cells
- shut down immune response when finished
- prevent inappropriate immune reactions
