E: Immunity Flashcards
what is immunity?
Ability to resist pathologies:
– Infection
– Disease
– Future Scenarios
Types:
– Specific
– Non-Specific
Immune system:
– All body cells and tissues involved in production of immunity
– Not just lymphatic system
immunity:
resistance?
susceptibility?
types of resistance
immunity is based on?
-Ability to ward off disease → Resistance
-Lack of ability → Susceptibility
-Types of resistance
– Specific
– Non-Specific
* Nonspecific resistance refers to a wide variety of body responses
against a wide range of pathogens
* Immunity is based on the ability to have a Specific
Response
specific defenses
Lymphocytes:
– Part of the immune response
– Identify, attack, and develop immunity to a specific
pathogen
– B and T lymphocytes confer “specific immunity”
- Arise when Non-specific defense (barriers + inflammation) fail to contain pathogen
non-specific defenses
-Block or attack any potential infectious organism
-Cannot distinguish one attack from another
-“non-specifics” are conferred through:
– Barriers- skin, mucosa
– Chemical barriers
– Inflammation, redness, swelling, heat, pain
– Fever
– Phagocytes
– Coughing and sneezing
– Production of tears, saliva
– Excreting urine, defecation and vomiting physically remove harmful substances
interferons:
1. alpha
2. beta
3. gamma
- Alpha
– Produced by leukocytes
– stimulate NK cells - Beta
– secreted by fibroblasts
– slow inflammation - Gamma
– secreted by T cells and NK cells
– stimulate macrophage activity
what are antigens?
antibodies?
relationship between these two?
Antigens: Targets which identify (label) any pathogenic substance or organism
Antibodies (Ab) are Immunoglobulin [Ig] Proteins
The binding of a specific antibody to its specific target antigen initiates antibody-mediated immunity: A chain of events which destroys the pathogen
what produces antibodies?
B cells - produce antibodies
T cells (helper, cytotoxic):
* Helper T cells regulate the immune response
* Cytotoxic T cells kill altered cells or pathogens
activation of inflammation includes:
opsonization
cytolysis
Opsonization – enhances phagocytosis
Cytolysis – membrane attack complex
what are humoral or antibody-mediated immunity?
cell mediated immunity?
Humoral or Antibody-mediated immunity:
-B cells which Build antibodies to specific proteins that bind
to specific antigens
Cell-mediated immunity:
-T cells: Cytotoxic lymphocytes attack virus infected or tumor cells directly
specific: humoral
B cells activation and antibody production requires:
1. B cell must encounter the antigen
2. IL-2 produced by T-helper must be present
* Steps 1 + 2 = Activation
– Yields:
* Plasma cells → Antibodies
* Memory cells → Save it for later
antibodies:
IgG
IgM
IgA
IgD and IgE
-Ig (immunoglobulin) G- active in blood against:
– bacteria and viruses
– helps activate complement
– helps phagocytes eliminate antigens
– most common antibody in the blood
-IgM: Reacts with certain antigens, usually on first exposure
-IgA: most common in mucosa
-IgD and IgE are rare in blood:
– IgE is involved in allergic reactions: sticks to mast cells, which release inflammatory substances
– IgD is usually found on B cells (not released): may be involved in B cell activation
where do bacteria and viruses often hide?
within the cells so that means antibodies can’t get to them
types of immunity:
natural active acquired immunity
artificial active acquired immunity
artificial passive acquired immunity
natural passive acquired immunity
-Natural active acquired immunity: person comes down with measles
-Artificial active acquired immunity: person is immunized with a vaccine
-Artificial passive acquired immunity: Person receives serum with antibodies
-Natural passive acquired immunity: Baby receives antibodies with mother’s milk - colostrum
