Question

Which of the following systems slows the heart rate, constricts the pupil and stimulates pancreatic activity during emergency conditions?

• A. Enteric nervous system
• B. Somatic nervous system
• C. Peripheral nervous system
• D. Parasympathetic division
• E. Sympathetic division

Answer 1

Answer: (D)

Parasympathetic division

Parasympathetic nervous system slows the heart rate, constricts the pupil and stimulates pancreatic activity during emergency conditions.

The parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

Heart rate is controlled by the two branches of the autonomic nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). The sympathetic nervous system (SNS) releases the hormones (catecholamines - epinephrine and norepinephrine) to accelerate the heart rate. The parasympathetic nervous system (PNS) releases the hormone acetylcholine to slow the heart rate.

The reduced heart rate results from an increase in activity of the parasympathetic nervous system, and perhaps from a decrease in activity of the sympathetic nervous system.

Examples of body functions stimulated by the parasympathetic nervous system include sexual arousal, salivation, lacrimation, urination, digestion, and defecation.

The parasympathetic nervous system is also known as the rest and digest activation, is the segment that assists with normal, autonomic functions. Typically all are in the control of the parasympathetic nervous system. Since this is the normal state of the body, the parasympathetic system is more active than the sympathetic system in controlling body functions.