Increased parasympathetic tone on the cervix produces what change?

• A. Increased cervical tone
• B. Relaxation of cervix
• C. Vasoconstriction
• D. Pain sensation

Answer: (A)

The main idea is how parasympathetic input affects cervical smooth muscle. Parasympathetic fibers release acetylcholine that acts on muscarinic receptors on smooth muscle, including the cervix. This tends to stimulate contraction of the cervical smooth muscle, increasing its tone or firmness. In other words, higher parasympathetic activity makes the cervix more tonically contracted rather than relaxed.

Vasoconstriction is governed mainly by sympathetic activity on vascular smooth muscle, not a direct effect of parasympathetic tone. Pain sensation is a sensory response, not a primary outcome of changing autonomic tone. Relaxation would be the opposite outcome of increased parasympathetic-driven contraction in this context.