| A | B |
|---|
| cell body | main part of the cell that contains the organelles |
| dendrites | one or more branches that carry the impulse to the cell body |
| axon | one projection or branche that carries the impulse away from the cell body |
| myelin | a white fatty substance around some asons that insulates the neuron to prevent short circuiting |
| Schwann cells | cells that produce myelin |
| neurilemma | outer cell membrane of neuron that makes it able to repair or regenerate |
| synapse | space between axon of one neuron and dendrite of another neuron |
| myoneural junction | space between axon of a neuron and a muscle fiber |
| neurotransmitter | chemical released by the axon into the synapse |
| central nervous system | brain and spinal cord |
| peripheral nervous system | all nerves outside the brain and spinal cord |
| sensory neuron | carry impulses to CNS |
| motor neuron | carry impulses from CNS |
| interneuron | carry impulses from sensory to motor neurons |
| afferent neuron | sensory neuron |
| efferent neuron | motor neuron |
| nerve | a group of axons in PNS |
| tract | a group of axons in CNS |
| white matter | myelinated fibers |
| gray matter | cell bodies and unmyelinated dendrites and axons |
| sensory nerve | made of only sensory neurons and carries impulses to CNS |
| motor nerve | made of only motor neurons and carries impulses from CNS |
| mixed nerve | made of both sensory and motor neurons and carries impulses to and from CNS |
| polarized | electrically balanced |
| receptor | dendrite of a sensory neuron |
| effector | muscle or gland affected by an impulse |
| ganglion | group of cell bodies in PNS |
| reflex arc | a pathway of nerve impulses that follow a one-way direction and elicit a quick response to a stimulus |
| meninges | connective tissue membranes that protect CNS |
| ventricles | fluid-filled spaces inside of the brain |
| plexus | network of branches from spinal nerves |
| somatic nerves | nerves that carry impulses to skeletal muscles for voluntary movement |
| autonomic nerves | nerves that carry impulses to smooth muscles, cardiac muscle, and glands for involuntary functions |
| cauda equina | group of spinal nerves at the end of the spinal cord |
