Somatic is to autonomic as is to a. rest; excitation b. voluntary; involuntary c. involuntary; voluntary d. excitation; rest

Somatic is to autonomic as voluntary is to involuntary.
The autonomic nervous system or visceral nervous system (also called vegetative nervous system) is the part of the nervous system responsible for functions not subject to voluntary control (like heart rate, breath...).

The somatic nervous system is the part of the peripheral nervous system that controls the movements and position of the body and allows to perceive through the skin various sensations (touch, heat, pain) and discover through the other sense organs the surrounding environment (like vision, hearing, olfaction...).

Both of the nervous systems consists of sensory neurons and motor neurons.

About rest and excitation, they are controlled by the two parts of the autonomic nervous system (sympathetic an parasympathetic).

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