Question

When epinephrine combines with alpha adrenergic receptors on smooth muscle in intestinal blood vessels, the blood vessels ________; however, when epinephrine binds to beta-2 adrenergic receptors on certain skeletal muscle blood vessels, the vessels ________.

Answer 1

Epinephrine causes constriction of intestinal blood vessels via alpha adrenergic receptors, whereas it causes dilation of blood vessels in skeletal muscle via beta-2 adrenergic receptors.

Step-by-step explanation:

When epinephrine combines with alpha adrenergic receptors on smooth muscle in intestinal blood vessels, the blood vessels constrict; however, when epinephrine binds to beta-2 adrenergic receptors on certain skeletal muscle blood vessels, the vessels dilate.

Epinephrine reacts with both α (alpha) and β (beta) adrenoreceptors, inducing different responses. In the presence of epinephrine, α-adrenergic receptors often trigger vasoconstriction in various blood vessels, which is useful during the fight-or-flight response to divert blood flow away from less critical areas such as the intestines. On the other hand, β-adrenergic receptors, particularly beta-2 receptors in skeletal muscles, can lead to vasodilation, thereby enhancing blood flow to muscles during times of stress or exercise.