Question

Which of the following can cause contraction of smooth muscle?

Electricity

Local metabolic factors

Drugs

Hormones (like epinephrine)

Temperature

Stretch

a) 1, 2, 3, 4, 5, 6
b) 2, 4, 5
c) 1, 3, 6
d) 2, 5, 4

Answer 1

Causes of smooth muscle contraction include local metabolic factors, hormones, drugs, temperature changes, and stretch.

Step-by-step explanation:

Smooth muscle contractions are influenced by various stimuli that are not under voluntary control, making smooth muscle an involuntary muscle. These stimuli include local metabolic factors, hormones like epinephrine, drugs, and temperature changes. Additionally, smooth muscle can respond to stretch, particularly in the walls of visceral organs with a phenomenon known as the stress-relaxation response. While electricity can stimulate contractions in smooth muscle, in the context of multiunit smooth muscle fibers, which are not electrically coupled, the stimuli for contractions are primarily autonomic nerves or hormones, but not stretching. Therefore, the correct answer includes local metabolic factors, drugs, hormones, temperature changes, and stretch as causes for the contraction of smooth muscle.