CH 20 - Hypersensitivity

Question 1

A type I hypersensitivity reaction is a

Answer 1

Anaphylactic reaction

Question 2

A type II hypersensitivity reaction is a

Answer 2

Cytotoxic reaction

Question 3

A type III hypersensitivity reaction is a

Answer 3

Immune complex reaction

Question 4

A type IV hypersensitivity reaction is a

Answer 4

Cell-mediated reaction

Question 5

With which cell type are anaphylactic reactions associated?

Answer 5

Mast

Question 6

Type III reactions are exemplified by all of the following except:

• Arthus reaction
• Shingles
• Serum sickness
• Glomerulonephritis

Answer 6

Shingles

Question 7

Type IV reactions are responsible for all of the following except:

• Hemolysis of red blood cells
• Contact sensitivity
• Delayed hypersensitivity
• Elimination of tumor cells bearing neoantigens

Answer 7

Hemolysis of red blood cells

Question 8

Type I hypersensitivity reactions can be associated with:

Answer 8

Food allergies, Hay fever, and Asthma

Question 9

The most common agents that cause anaphylactic reactions are

Answer 9

Drugs and insect stings

Question 10

Arrange the sequence of events in anaphylaxis in the proper order

• Activated mast cells and basophils release various mediators.
• The offending antigen attaches to the IgE antibody fixed to the surface membrane of mast cells and basophils
• The effects of mediator release produce vascular changes, activation of platelets, eosinophils and neutrophils, and activation of the coagulation cascade.

Answer 10

1: The offending antigen attaches to the IgE antibody fixed to the surface membrane of mast cells and basophils

2: Activated mast cells and basophils release various mediators.

3: The effects of mediator release produce vascular changes, activation of platelets, eosinophils and neutrophils, and activation of the coagulation cascade.

Question 11

Histamine as a mediator of anaphylaxis:

Answer 11

Increases vascular permeability and promotes contraction of smooth muscle

Question 12

Leukotrienes as a mediator of anaphylaxis:

Answer 12

Enhance the effects of histamine on target organs

Question 13

Cytotoxic reactions are characterized by the interaction of

Answer 13

IgM or IgG to cell-bound antigen

Question 14

An example of a delayed nonhemolytic (type II hypersensitivity) reaction is:

Answer 14

Graft-versus-host disease

Question 15

Under normal conditions, immune complexes protect the host because they

Answer 15

1. Facilitate the clearance of various antigens

AND

2. Facilitate the clearance of invading microorganisms

Question 16

Immune complexes can

Answer 16

1. Suppress or augment the immune response by interacting with T and B cells

AND

2. Inhibit tumor cell destruction

AND

3. Be deposited in blood vessel walls

Question 17

The general anatomic sites of antigen–antibody interaction are

Answer 17

1. Tissues with a large filtration area

AND

2. Interstitial fluids

AND

3. Cell surface membranes or fixed intercellular structures

Question 18

Type IV hypersensitivity reactions are responsible for all of the following except:

• Rejection of foreign tissue grafts
• Contact sensitivity
• Serum sickness
• Elimination of tumor cells

Answer 18

Serum sickness