Anatomy & Physiology Nervous #4

Question

Which is a result of stimulation to the sympathetic nervous system?

Answers

  1. A decreased pupil size.
    • Rationale:

      Stimulation of the SNS causes the pupils to dilate, not constrict; therefore, this is not an expected response.

  2. An increased heart rate.
    • Rationale:

      Stimulation of the SNS causes a release of epinephrine which increases the heart rate; therefore, this is an expected response.

  3. A decreased respiratory rate.
    • Rationale:

      Stimulation of the SNS causes an increased rate of respiration; therefore, a decreased respiratory rate is not an expected response.

  4. An increased rate of digestion.
    • Rationale:

      Stimulation of the SNS lowers the rate of digestion; therefore, an increased rate of digestive function is not an expected response.

Overview

The sympathetic nervous system (SNS) is a division of the autonomic nervous system (ANS).

Explanation

Learning Outcomes

The SNS causes fight-or-flight responses within the body as a result of the neurotransmitter, epinephrine. Epinephrine causes an increased heart rate and respiratory rate. In addition, stimulation of the SNS decreases the rate of digestion and also causes the pupils to dilate.

Test Taking Tip

Consider the function of the sympathetic nervous system (PNS) to eliminate wrong choices when answering this question.

Video Rationale