Chapter 21 Immune System Flashcards
Innate immune system
- Non-specific, born with this system
- Protective barriers (skin)
- General chemical signals
Adaptive immune system
- Specific, adapted
- Response specific to antigen
Pathogen
-Harmful, disease causing microorganisms
Mechanical barrier
-Physical obstruction
Lysozyme
-In saliva to destroy bacteria
Phagocytes
-Primary types are macrophages derived from monocytes (free or fixed)
Natural killer cells (NK)
- Cells in the blood and lymph that lyse and kill cancer cells and virus infected cells
- Recognize cell surface sugars
- Release perforins to attack membranes
Hyperemia
-The redness and heat of blood congesting in an area
Exudate
-Fluid with clotting factors and antibodies from bloodstream into tissue spaces
Edema
-Swelling and pain by stimulating nerves
Leukocytosis
-Promote release of neutrophils from red-marrow
Margination
-Inflamed areas sprout cell adhesion molecules (CAMs) providing footholds for neutrophils to cling to damaged area
Diapedesis
-Neutrophils squeeze through capillary walls
Chemotaxis
-Neutrophils follow chemical gradient to site of the injury
Antimicrobial proteins
-Interfere with microorganisms’ ability to reproduce
Interferon
- Act against malignant cells
- Reduce inflammation in injured areas
- Activate macrophages and mobilize natural killer cells
Complement
- Destroy foreign substances in the body by amplifying the inflammation process
- Kill bacteria by lysis
Humoral immunity
- Antibody mediated immunity
- Antibodies bind to antigens and mark them for destruction by phagocytes
Cellular immunity
- Cell mediated immunity
- Lymphocytes defend themselves directly
Antigen
- Any foreign substance in the body that mobilize an immune response
- Target of immune system (nonself)
Complete antigen
- Immunogenicity: stimulates proliferation of specific lymphocytes and antibodies
- Reactivity: Have the ability to react to the activated lymphocytes and antibodies
Hapten
- Small molecules causing an allergic reaction
- Mount an attack once linked to body’s defenses
MHC
- Major histocompatability complex
- Cell external surfaces have protein molecules, termed self antigens
- Glycoproteins mark cells as self
- Class I: found on all cells
- Class II: only certain cells acting in immune response
Immunocompetent
-Able to recognize and bind to an antigen
Humoral immune response
- Antigen challenge: first encounter between antigen and naive immunocompetent cell
- If a B cell provokes a humoral immune response, antibodies are produced against the challenger
Antigen challenge
-first encounter between antigen and naive immunocompetent cell
Plasma cell
-Antibody secreting effector cells of the humoral response
Memory cell
-Can mount an almost immediate humoral response if they encounter the same antigen in the future
Clone cells
- Most become plasma cells
- Other cells become memory cells
Active humoral immunity
-Encounter antigen and produce antibody
Passive humoral immunity
-Antibodies from external source, no response
Naturally acquired active humoral immunity
-Infection, contact with pathogen
Artificially acquired active humoral immunity
-Vaccine, dead or attenuated pathogens
Naturally acquired passive humoral immunity
-Antibodies pass from mother to fetus
Artificially acquired passive humoral immunity
-Injection of immune serum (gamma globulin)
C region
-Form stem of antibody, the effector region
V region
-Antigen binding of antibody site shaped to fit a specific antigenic determinant
Lethal hit
- Bind and release perforin into the plasma membrane
- Detaches and continues
- Perforins create transmembrane pores, causing cell lysis
Perforin
-Create transmembrane pores during a lethal hit, causing cell lysis
Lymphotoxin
-Fragments target cell DNA
Tumor necrosis factor
-Triggers apoptosis (programmed cell death) in 48-72 hours
Gamma interferon
-Stimulates macrophages to killer status, enhancing phagocytosis
Autograft
-Transplants within the same person
Isograft
-Grafts between genetically identical twins
Allograft
-Grafts between individuals that are not genetically identical, but of the same species (most transplants)
Xenograft
-Grafts taken from another animal
Immunodeficiency
-
SCID
-Severe combined immunodeficiency syndromes (The Bubble Boy)
Hodgkin disease
-Cancer of the lymph nodes
AIDS
- Acquired immune deficiency syndrome
- Destroys the effectiveness of CD4 cells
Autoimmune disease
-Both congenital and acquired conditions causing abnormal function in phagocytes, immune cells, or complement
Hypersensitivity
- Fighting a perceived threat: allergen
- Immediate, subacute, delayed
Anaphylaxis
- First exposure sensitizes the person without symptoms
- Produce huge amounts of antibody (IgE), and attach to mast cells and basophils
- Second encounter: flood of histamine and inflammatory chemicals
Atopy
-Spontaneous allergy without previous exposure
Delayed hypersensitivity
- Cell mediated hypersensitivity including both cytotoxic and hypersensitive T-cells
- Contact dermatitis
- Protection against pathogens, cancer, foreign grafts and organs
