Adrenaline is a hormone that prepares the body for rapid responses by increasing the blood flow
to muscles and increasing blood sugar concentrations. Adrenaline is secreted from the adrenal
glands and acts on nearly all body tissues by binding to adrenergic receptors on the surface of
the cells.
Different tissues respond to adrenaline in different ways. For example, adrenaline causes smooth
muscle in the airways to relax but causes contraction of smooth muscle in arterioles.
What could explain the different responses of smooth muscle to adrenaline?