Parasympathetic activation commonly leads to which effect?

Parasympathetic activation commonly leads to which effect?

• A. Increased Heart Rate
• B. Slows Digestion
• C. Pupillary Constriction
• D. Dilation of Blood Vessels in Limbs

Answer: (C)

Parasympathetic activation promotes rest-and-digest actions. A key effect is constriction of the pupil (miosis) when the iris sphincter muscle contracts under acetylcholine acting on muscarinic receptors. This fits the calm, non-emergency state the parasympathetic system supports. In contrast, increased heart rate and dilation of blood vessels in the limbs are typical sympathetic responses, and slowing digestion would not describe parasympathetic activity (it actually enhances digestion). So pupillary constriction is the correct effect.

Parasympathetic activation promotes rest-and-digest actions. A key effect is constriction of the pupil (miosis) when the iris sphincter muscle contracts under acetylcholine acting on muscarinic receptors. This fits the calm, non-emergency state the parasympathetic system supports. In contrast, increased heart rate and dilation of blood vessels in the limbs are typical sympathetic responses, and slowing digestion would not describe parasympathetic activity (it actually enhances digestion). So pupillary constriction is the correct effect.