Excessive activity of the neurotransmitter norepinephrine contributes to a slowdown of the:

A) immune system.
B) autonomic nervous system.
C) sympathetic nervous system.
D) cardiovascular system.

Autonomic Nervous System

The part of the peripheral nervous system that controls involuntary bodily functions, including heart rate, digestion, and breathing.

Sympathetic Nervous System

Part of the autonomic nervous system that activates what is often termed the fight or flight response.

Immune System

is the body's defense mechanism against infections, diseases, and other potentially harmful foreign bodies.