Module 10 — Nervous System

Nervous system

The body’s fast electrochemical communication network, consisting of the central and peripheral nervous systems.

Central nervous system (CNS)

The brain and spinal cord.

Peripheral nervous system (PNS)

Sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundles of axons that connect the CNS with muscles, glands, and sensory organs.

Sensory (afferent) neurons

Carry incoming information FROM the body TO the brain and spinal cord.

Motor (efferent) neurons

Carry outgoing information FROM the brain and spinal cord TO muscles and glands.

Interneurons

Neurons within the brain and spinal cord that process information between sensory inputs and motor outputs.

Somatic nervous system

Division of the PNS that controls skeletal muscles and voluntary movement.

Autonomic nervous system (ANS)

Division of the PNS that controls glands and internal organs; its sympathetic division arouses the body, while its parasympathetic division calms it.

Sympathetic nervous system

Division of the ANS that arouses the body and mobilizes energy.

Parasympathetic nervous system

Division of the ANS that calms the body and conserves energy.

Reflex

A simple, automatic response to a sensory stimulus, such as a knee-jerk response.