Chapter 34, Problem 7STP

Summary Introduction

Introduction :

The two primary branches of the nervous system are the central nervous system and the peripheral nervous system. The central nervous system consists of the spinal cord and the brain. The peripheral nervous system consists of motor neurons and neurons which carry data from and to the central nervous system.

Answer to Problem 7STP

Correct answer :

The correct answer is option (A) decreased heart rate.

Explanation of Solution

Explanation/justification for the correct answer :

Option (A) decreased heart rate. ANS has two branches- the sympathetic nervous system and parasympathetic nervous system. The parasympathetic nervous system is most active when the body is relaxed. Parasympathetic stimulation decreases heart rate and force, increase motility, secreted gastric juice, etc. So, this is the correct option.

Explanation for incorrect answer :

Option (B) decreased mucus production. Parasympathetic stimulation increased mucus production of the oral and nasal mucosa. So, this is an incorrect option.

Option (C) increased digestive activity. Parasympathetic stimulation increased digestion in the small intestine. So, this is an incorrect answer.

Option (D) increased pupil size. The pupil size in iris decreased in parasympathetic stimulation. So, this is an incorrect answer.