cell body Part of a neuron that contains the nucleus and other organelles.
central nervous system Part of the nervous system that includes the brain and spinal
cord.
cerebellum Part of the brain that controls body position, coordination, and balance.
cerebrum Part of the brain that controls awareness and voluntary movements.
dendrite Part of a neuron that receives nerve impulses from other cells and passes them
on to the cell body.
hemisphere One of the two halves of the cerebrum.
motor division Division of the peripheral nervous system that carries messages from the
central nervous system to internal organs, glands, and muscles.
motor neuron Neuron that carries nerve impulses from the central nervous system to
internal organs, glands, or muscles.
nerve Bundle of individual nerve cells.
nerve impulse Electrical signal that is transmitted by neurons.
nervous system Body system that controls all the other systems of the body.
neuron Nerve cell that carries electrical messages.
neurotransmitter Chemical that carries nerve impulses from the axon of one neuron to
the dendrite of the next neuron.
parasympathetic division Division of the autonomic nervous system that controls body
processes under nonemergency conditions.
peripheral nervous system All the nerves of the body that lie outside the central ner-
vous system.
sensory division Division of the peripheral nervous system that carries messages from the
sense organs and internal organs to the central nervous system.