NR507 Advanced Pathophysiology MidTerm.pdf file:///C:/Users/HP/Desktop/New%20folder/NR507%20Advanced%2
NR507 Advanced Pathophysiology MidTerm
1. Hypersensitivity:Type 1: Type 1: Allergic reaction, Mediated by IgE, Inflamma-
tion due to mast cell degranulation
Local symptoms:
-itching
-rash
Systemic symptoms:
-wheezing
Most dangerous = anaphylactic reaction
systemic response of hypotension, severe bronchoconstriction
Main treatment: epinephrine reverses the effects
2. Hypersensitivity:Type 2: Type 2: Cytotoxic reaction; tissue specific (ex: thyroid
tissue)
Macrophages are the primary effectors cells involved
Can cause tissue damage or alter function
Grave's disease (hyperthyroidism) - example of altering thyroid function, but does
1 of 25 12/16/2024, 5:30
,NR507 Advanced Pathophysiology MidTerm.pdf file:///C:/Users/HP/Desktop/New%20folder/NR507%20Advanced%2
not destroy thyroid tissue
Incompatible blood type- example of cell/tissue damage that occurs; severe transfu-
sion reaction occurs and the transfused erythrocytes are destroyed by agglutinationor
complement-mediated lysis.
3. Type 1 Hypersensitivity VS.Type 2 Hypersensitivity: Type 1 Hypersensitivity
Organ Specific
Antibody binds to the antigen on the cell surface
Type 2 Hypersensitivity
Not Organ Specific
Antibody binds to the soluble antigen outside the cell surface that was released into
the blood or body fluids, and the complex is then deposited in the tissues
4. Hypersensitivity:Type 3 - Examples: Rheumatoid arthritis: Antigen/antibodies
are deposited in the joints
Systemic Lupus Erythematosus (SLE)- very closely related to autoimmunity- anti-
gen/antibodies deposit in organs that cause tissue damage
5. Hypersensitivity:Type 4: Delayed response
2 of 25 12/16/2024, 5:30
,NR507 Advanced Pathophysiology MidTerm.pdf file:///C:/Users/HP/Desktop/New%20folder/NR507%20Advanced%2
Does not involve antigen/antibody complexes like Types 1, 2 and 3
Is T-cell mediated
6. Differentiating Between the Rash of a Type 1 vs. Type 4 Reaction:: Type 1:
Immediate hypersensitivity reactions, termed atopic dermatitis, are usually charac-
terized by widely distributed lesions
Type 4: Contact dermatitis (delayed hypersensitivity) consists of lesions only at the
site of contact with the allergen
The key determinant is the timing of the rash:
-Type 1 = Immediate
-Type 4 = Delayed: Several days following contact, ex would be poison ivy
7. Treatment of Type 4 Rash: A non-severe case of contact dermatitis would be
treated with topical corticosteroid.
Why not epinephrine or antihistamines?
-Epinephrine is for emergent Type 1 anaphylactic reactions. Antihistamines act onthe
H1 receptors. Type 4 does not involve mast cells and H1 receptors.
3 of 25 12/16/2024, 5:30
NR507 Advanced Pathophysiology MidTerm
1. Hypersensitivity:Type 1: Type 1: Allergic reaction, Mediated by IgE, Inflamma-
tion due to mast cell degranulation
Local symptoms:
-itching
-rash
Systemic symptoms:
-wheezing
Most dangerous = anaphylactic reaction
systemic response of hypotension, severe bronchoconstriction
Main treatment: epinephrine reverses the effects
2. Hypersensitivity:Type 2: Type 2: Cytotoxic reaction; tissue specific (ex: thyroid
tissue)
Macrophages are the primary effectors cells involved
Can cause tissue damage or alter function
Grave's disease (hyperthyroidism) - example of altering thyroid function, but does
1 of 25 12/16/2024, 5:30
,NR507 Advanced Pathophysiology MidTerm.pdf file:///C:/Users/HP/Desktop/New%20folder/NR507%20Advanced%2
not destroy thyroid tissue
Incompatible blood type- example of cell/tissue damage that occurs; severe transfu-
sion reaction occurs and the transfused erythrocytes are destroyed by agglutinationor
complement-mediated lysis.
3. Type 1 Hypersensitivity VS.Type 2 Hypersensitivity: Type 1 Hypersensitivity
Organ Specific
Antibody binds to the antigen on the cell surface
Type 2 Hypersensitivity
Not Organ Specific
Antibody binds to the soluble antigen outside the cell surface that was released into
the blood or body fluids, and the complex is then deposited in the tissues
4. Hypersensitivity:Type 3 - Examples: Rheumatoid arthritis: Antigen/antibodies
are deposited in the joints
Systemic Lupus Erythematosus (SLE)- very closely related to autoimmunity- anti-
gen/antibodies deposit in organs that cause tissue damage
5. Hypersensitivity:Type 4: Delayed response
2 of 25 12/16/2024, 5:30
,NR507 Advanced Pathophysiology MidTerm.pdf file:///C:/Users/HP/Desktop/New%20folder/NR507%20Advanced%2
Does not involve antigen/antibody complexes like Types 1, 2 and 3
Is T-cell mediated
6. Differentiating Between the Rash of a Type 1 vs. Type 4 Reaction:: Type 1:
Immediate hypersensitivity reactions, termed atopic dermatitis, are usually charac-
terized by widely distributed lesions
Type 4: Contact dermatitis (delayed hypersensitivity) consists of lesions only at the
site of contact with the allergen
The key determinant is the timing of the rash:
-Type 1 = Immediate
-Type 4 = Delayed: Several days following contact, ex would be poison ivy
7. Treatment of Type 4 Rash: A non-severe case of contact dermatitis would be
treated with topical corticosteroid.
Why not epinephrine or antihistamines?
-Epinephrine is for emergent Type 1 anaphylactic reactions. Antihistamines act onthe
H1 receptors. Type 4 does not involve mast cells and H1 receptors.
3 of 25 12/16/2024, 5:30
