Which receptor activation leads to bronchodilation?

Prepare for the Care Flight Entrance Exam with our comprehensive study materials. Use flashcards and multiple-choice questions, complete with hints and explanations, to enhance your readiness. Get ready to soar in your exam!

Multiple Choice

Which receptor activation leads to bronchodilation?

Explanation:
Bronchodilation happens when beta-2 adrenergic receptors on bronchial smooth muscle are activated. These receptors are linked to a Gs protein, which boosts adenylyl cyclase activity and raises cAMP levels. Higher cAMP activates PKA, which lowers intracellular calcium and relaxes the smooth muscle, widening the airways. Activation also dampens release of bronchoconstrictive mediators from mast cells, further promoting dilation. Other receptors listed mainly drive constriction or cardiac effects (beta-1 in the heart, alpha-1 and V1 causing vasoconstriction) and do not produce bronchodilation. So, beta-2 receptor activation is what leads to bronchodilation.

Bronchodilation happens when beta-2 adrenergic receptors on bronchial smooth muscle are activated. These receptors are linked to a Gs protein, which boosts adenylyl cyclase activity and raises cAMP levels. Higher cAMP activates PKA, which lowers intracellular calcium and relaxes the smooth muscle, widening the airways. Activation also dampens release of bronchoconstrictive mediators from mast cells, further promoting dilation. Other receptors listed mainly drive constriction or cardiac effects (beta-1 in the heart, alpha-1 and V1 causing vasoconstriction) and do not produce bronchodilation. So, beta-2 receptor activation is what leads to bronchodilation.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy