NR507 Boosted
Pathophysiology MidTerm
With Validated Solutions
2025/2026
Hypersensitivity: Type 1 - Correct Answers-Type 1: Allergic reaction,
Mediated by IgE, Inflammation 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
Hypersensitivity: Type 2 - Correct Answers-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 not destroy thyroid tissue
Incompatible blood type- example of cell/tissue damage that occurs; severe
transfusion reaction occurs and the transfused erythrocytes are destroyed by
agglutination or complement-mediated lysis.
Type 1 Hypersensitivity VS. Type 2 Hypersensitivity - Correct Answers-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
Hypersensitivity: Type 3 - Examples - Correct Answers-Rheumatoid arthritis:
Antigen/antibodies are deposited in the joints
Systemic Lupus Erythematosus (SLE)- very closely related to autoimmunity-
antigen/antibodies deposit in organs that cause tissue damage
Hypersensitivity: Type 4 - Correct Answers-Delayed response
Does not involve antigen/antibody complexes like Types 1, 2 and 3
Is T-cell mediated
Differentiating Between the Rash of a Type 1 vs. Type 4 Reaction: - Correct
Answers-Type 1: Immediate hypersensitivity reactions, termed atopic
dermatitis, are usually characterized 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
Treatment of Type 4 Rash - Correct Answers-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 on the H1 receptors. Type 4 does not involve mast cells and H1
receptors.
Antibiotics not appropriate since not an infection
Autoimmunity - Correct Answers-Autoimmune disease can be familial,
Affected family members may not all develop the same disease, but several
members may have different disorders characterized by a variety of
hypersensitivity reactions, These include autoimmune and allergic reactions
Associations with particular autoimmune diseases have been identified for a
variety of major histocompatibility complex (MHC) alleles or non-MHC genes
Pathophysiology MidTerm
With Validated Solutions
2025/2026
Hypersensitivity: Type 1 - Correct Answers-Type 1: Allergic reaction,
Mediated by IgE, Inflammation 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
Hypersensitivity: Type 2 - Correct Answers-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 not destroy thyroid tissue
Incompatible blood type- example of cell/tissue damage that occurs; severe
transfusion reaction occurs and the transfused erythrocytes are destroyed by
agglutination or complement-mediated lysis.
Type 1 Hypersensitivity VS. Type 2 Hypersensitivity - Correct Answers-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
Hypersensitivity: Type 3 - Examples - Correct Answers-Rheumatoid arthritis:
Antigen/antibodies are deposited in the joints
Systemic Lupus Erythematosus (SLE)- very closely related to autoimmunity-
antigen/antibodies deposit in organs that cause tissue damage
Hypersensitivity: Type 4 - Correct Answers-Delayed response
Does not involve antigen/antibody complexes like Types 1, 2 and 3
Is T-cell mediated
Differentiating Between the Rash of a Type 1 vs. Type 4 Reaction: - Correct
Answers-Type 1: Immediate hypersensitivity reactions, termed atopic
dermatitis, are usually characterized 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
Treatment of Type 4 Rash - Correct Answers-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 on the H1 receptors. Type 4 does not involve mast cells and H1
receptors.
Antibiotics not appropriate since not an infection
Autoimmunity - Correct Answers-Autoimmune disease can be familial,
Affected family members may not all develop the same disease, but several
members may have different disorders characterized by a variety of
hypersensitivity reactions, These include autoimmune and allergic reactions
Associations with particular autoimmune diseases have been identified for a
variety of major histocompatibility complex (MHC) alleles or non-MHC genes
