Question

multiple choice 2 points

the parasympathetic division of the autonomic nervous system has what effect on blood vessels?

no effect at all
increases blood pressure
both constricts blood vessels in viscera and increases blood pressure
constricts blood vessels in viscera

Explanation:

Analyze autonomic vascular control

Using the Autonomic Nervous System and Autonomic Tone knowledge points

Most blood vessels in the body receive innervation exclusively from the sympathetic division of the autonomic nervous system. Sympathetic tone maintains a baseline level of constriction (vasomotor tone). Changes in blood vessel diameter are primarily regulated by increasing or decreasing sympathetic stimulation, rather than dual innervation.

Evaluate parasympathetic effects

Using the Sympathetic Nervous System knowledge point

The parasympathetic division does not innervate most systemic blood vessels (with minor exceptions such as those in the external genitalia and salivary glands). Therefore, on a systemic level, the parasympathetic division has no direct effect on blood vessels.

Match with options

The option "no effect at all" correctly describes the general systemic effect of the parasympathetic division on blood vessels.

Answer:

• (A) no effect at all (Correct answer)
• (B) increases blood pressure
• (C) Both constricts blood vessels in viscera and increases blood pressure
• (D) constricts blood vessels in viscera