Nervous System Glossary

For Quiz on 1/6

Autonomic Nervous System (ANS)

sensory input from the viscera and blood vessels, and motor output to involuntary effectors (cardiac muscle, smooth muscle, glands)

Axon

single long process of a neuron that conducts nerve impulses away from the cell body

cortex

thin, superficial layer of gray matter that covers the cerebrum and cerebellum

dendrites

highly branched processes of a neuron that carry impulses to the cell body (main receiving or input region)

Enteric plexus

network of neurons in the walls of the gastrointestinal (GI) track

Fasciculus

axon bundles of a nerve

Ganglion (ganglia: plural)

cluster of cell bodies and the synaptic region for neurons located in the PNS

gray matter

contains cell bodies, dendrites, axon terminals of neurons, unmyelinated axons, and neuroglia

Interneurons (association neurons)

multipolar neurons located within the CNS that integrate incoming sensory information to elicit a motor response

Motor (efferent) neuron

multipolar neurons, convey impulses from the CNS out through the PNS to effectors (“involuntary” muscles or glands)

Nerve

bundle of axons in the PNS

Nucleus

cluster of cell bodies and the synaptic region for neurons located in the CNS

Neuroglia

cells that support, nourish, and protect neurons

Neurons

nervous tissue cells that are specialized for nerve impulse conduction

Parasympathetic Division

division of the ANS that performs our housekeeping activities and conserves energy (“rest and digest”)

Perception

our awareness of sensory input (stimuli)

Sensory (afferent) neurons

unipolar (pseudo-unipolar) neurons, convey stimuli impulses to the CNS for integration

Sensory Receptors

monitor and transduce changes in our internal and external environments

spinal cord

gray matter forms an H-shaped inner core surrounded by white matter

soma

cell body of neurons that contain the typical organelles plus chromatophilic (Nissl) bodies

Somatic Nervous System (SNS)

sensory input from the head, body wall, limbs, and special sense organs and motor output to “voluntary” skeletal muscles

Sympathetic Division

division of the ANS that is activated under stressful situations (“fight or flight“)

Tract

bundle of axons in the CNS

white matter

aggregates of myelinated axons