TESTED AND CONFIRMED A+ ANSWERS
In which structure does B lymphocytes mature and undergo changes that commit
them to becoming B cells?
Thymus
... [Show More] gland
Regional lymph nodes
Bone marrow
Spleen - ANSWER- ANS: C
RATIONALE: B lymphocytes mature and become B cells in specialized (primary)
lymphoid organs—the thymus gland for T cells and the bone marrow for B cells.
Neither regional lymph nodes nor the spleen are involved in changing B
lymphocytes into B cells.
An individual's acquired immunity is dependent on the function of which cells?
(Select all that apply.)
T lymphocytes
B lymphocytes
Macrophages
Opsonins
Neutrophils - ANSWER- ANS: A, B, C
RATIONALE: T lymphocytes, B lymphocytes, macrophages, and dendritic cells
are involved in acquired immunity. Opsonins are molecules that tag
microorganisms for destruction by cells of the inflammatory system; these cells are
primarily neutrophils. Neutrophils are white blood cells.
The common hay fever allergy is expressed through a reaction that is mediated by
which class of immunoglobulins?
IgE
IgG
IgM
T cells - ANSWER- ANS: A
RATIONALE: Type I reactions are mediated by antigen-specific IgE and the
products of tissue mast cells. The most common allergies (e.g., pollen allergies) are
type I reactions. In addition, most type I reactions occur against environmental
antigens and are therefore allergic. Hay fever allergy is not mediated by IgG, IgM,
or T cells.
During an IgE-mediated hypersensitivity reaction, which leukocyte is activated?
a. Neutrophils
b. Monocytes
c. Eosinophils
d. T lymphocytes - ANSWER- ANS: C
RATIONALE: Of the options provided, only eosinophils are activated during IgEmediated hypersensitivity reactions.
During an IgE-mediated hypersensitivity reaction, what causes bronchospasm?
a. Bronchial edema caused by the chemotactic factor of anaphylaxis
b. Bronchial edema caused by binding of the cytotropic antibody
c. Smooth muscle contraction caused by histamine bound to H1 receptors
d. Smooth muscle contraction caused by histamine bound to H2 receptors -
ANSWER- ANS: C
RATIONALE: During an IgE-mediated hypersensitivity reaction, smooth muscle
contraction caused by histamine bound to H1 receptors results in bronchospasms.
The bronchospasm is not caused by edema or by histamine binding to H2
receptors.
A patient is having an IgE-mediated hypersensitivity reaction. What action by the
healthcare professional is best?
a. Give the patient an antihistamine.
b. Prepare to give the patient a blood transfusion.
c. Ask the patient is he/she is having pain at the site.
d. Apply warm, moist heat to the affected area. - ANSWER- ANS: A
RATIONALE: Histamine is the most potent mediator in an IgE-mediated
hypersensitivity reaction (Type 1). Histamine bound to H2 results in the
degranulation of mast cells with the release of histamine. Blocking histamine
receptors with antihistamines can control some type I responses. The healthcare
professional would not need to give the patient blood; warm; moist heat; or ask
about pain [Show Less]