The sympathetic nervous system
A) is always excitatory for smooth muscle
B) innervates only tissues concerned with protecting the body against challenges from the outside environment
C) dominates in rest-and-digest situations
D) contains cholinergic and adrenergic fibers
E) contains cholinergic and adrenergic fibers and is always excitatory for smooth muscle

Question

Quizplus · Accepted Answer

The sympathetic nervous system contains both cholinergic (which release acetylcholine) and adrenergic (which release epinephrine or norepinephrine) fibers. It is not always excitatory for smooth muscle, and it innervates many types of tissues, not just those concerned with protection against external challenges. The sympathetic nervous system typically dominates in fight-or-flight situations, not rest-and-digest.

The Sympathetic Nervous System