Histamine is a Mediator of Allergic Reactions That Causes

Question

Histamine is a mediator of allergic reactions that causes
A)no effect on bronchioles.
B)bronchoconstriction.
C)bronchodilation.
D)smooth muscle spasm.
E)vasoconstriction of pulmonary capillaries.

Accepted Answer

Histamine causes bronchoconstriction, which is a narrowing of the airways in the lungs that can lead to difficulty breathing. This is a common symptom of asthma and other allergic respiratory conditions. Histamine does not have any significant effect on bronchodilation, smooth muscle spasm, or vasoconstriction of pulmonary capillaries.