Term
|
Definition
| Disorders of the immune system. |
|
|
Term
| What are the two groups of immunopathologies? |
|
Definition
Hypersensitivity
Hyposensitivity |
|
|
Term
|
Definition
| A type of hypersensitivity - allergy is NOT interchangeable with hypersensitivity |
|
|
Term
|
Definition
| An immune system that reacts to particles that are innocuous in non-allergic individuals. |
|
|
Term
| What are the two sources of hypersensitivity? |
|
Definition
Exogenous - allergies
Endogenous - autoimmunity |
|
|
Term
| What is the biological basis for hypersensitivity? |
|
Definition
| It's speculated that our immune system is naturally overactive, but now that our environments are so clean, they just find other things to target. |
|
|
Term
| Types I-III hypersensitivity |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Immediate hypersensitivity - all reactions are IgE-mediated.
Two types: Atopy (local & chronic), Anaphylaxis (systemic & acute)
All reactions are two-stage. |
|
|
Term
|
Definition
| Usually proteins, but sometimes haptens, that trigger an inappropriate immune response |
|
|
Term
|
Definition
| A very small, nonproteinaceous compound that complexes with other materials to become large enough to be recognized. |
|
|
Term
| What are the common portals of entry for allergens? |
|
Definition
Respiratory system
GI system
Circulatory system
Dermal system |
|
|
Term
| What is the first stage of a type I immune reaction? |
|
Definition
| This is the sensitizing dose, during which exposure occurs for the first time, and IgE specific for the allergen binds to a granulocyte, "priming" it for future contact. |
|
|
Term
| What is the second stage of a type I reaction? |
|
Definition
| Primed granulocytes come in contact with the allergen and, even though there's nothing to attack, release granules, causing an inappropriate immune response. This causes the symptoms of an allergic reaction. |
|
|
Term
| What are some common forms of atopy? |
|
Definition
Allergic rhinitis (hay fever)
Asthma
Atopic dermatitis (eczema)
Food allergies
Drug allergies (some classify as type II) |
|
|
Term
|
Definition
| Dose of allergen is much larger, so the magnitude of reaction is much greater. About a third have undetermined causes. |
|
|
Term
| What are the two types of anaphylaxis? |
|
Definition
Cutaneous (wheal-and-flare)
Systemic (circulorespiratory distress) |
|
|
Term
|
Definition
IgG or IgM triggers a complement cascade that results in cell destruction.
Included in this category are blood type incompatibilities and some types of autoimmunity.
Stimuli are alloantigens - molecules that differ within a species |
|
|
Term
| How are fetuses (allografts) tolerated? |
|
Definition
The placenta serves as a nonimmunogenic tissue and promotes local immunosuppressive responses.
Placenta expresses special MHC molecules that inhibit NK cells, produces immunosuppressive cytokines |
|
|
Term
| Type III hypersensitivity |
|
Definition
| IgG or IgM binds to antigens in large volumes, causing them to fall out of circulation, attracting complement. Neutrophils try to clear them, but in order to do so, must clear the surrounding tissue. |
|
|
Term
|
Definition
| Localized dermal response to allergens, through contact or injection. Typically short and self-limiting. |
|
|
Term
|
Definition
| Systemic response to injected allergens, which can become chronic. |
|
|
Term
|
Definition
T cells react to antigens on foreign or self cells.
Two main types: contact dermatitis and graft rejection |
|
|
Term
|
Definition
| Active component in poison ivy |
|
|
Term
|
Definition
| Type IV hypersensitivity, in which the host rejects the graft or the graft rejects the host. |
|
|
Term
|
Definition
| An inappropriate response to self, sometimes congenital, sometimes developed. |
|
|
Term
|
Definition
| Antibodies that recognize self, produced in small, constitutive levels in everyone, for "self-cleanup" activites. |
|
|
