Select the correct answer to the questions from the given options. (Do not copy the questions, write the correct answer only.)
Stimulation of the nerves of the sympathetic nervous system:
Topic: Sympathetic nervous system
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) Accelerates heartbeat.
The sympathetic system produces the FIGHT-OR-FLIGHT response, so ask of each option: would this help someone about to fight or run?
(A) ACCELERATES HEARTBEAT — yes. More blood to the muscles. CORRECT. (B) Constricts the pupil — no, the sympathetic system DILATES the pupil to let in more light. (C) Increases peristalsis — no, digestion is SLOWED; blood is diverted away from the gut to the muscles. (D) Retards heartbeat — the opposite of the truth.
Options (b), (c) and (d) are all PARASYMPATHETIC effects — the "rest and digest" system, which does exactly the reverse in every case.
THE SINGLE TEST answers every question on this topic and is worth more than any list: does the change prepare the body for sudden action?
Accelerates heartbeat.