| Term | Definition |
|---|
| action potential | the sequence of electrical changes when a nerve cell membrane is exposed to a stimulus that exceeds its threshhold |
| autonomic nervous system | portion of nervous system that controls the actions of the viscera |
| axon | a nerve fiber that conducts a nerve impulse away from a neuron cell body |
| central nervous system | portion of nervous system that consists of the brain and spinal cord |
| chromatophilic substances | membranous sacs within cytoplasm of nerve cells that have ribosomes attached to their surfaces |
| convergence | nerve impulses arrive at the same neuron |
| dendrite | nerve fiber that transmits impulses toward a neuron cell body |
| divergence | a spreading apart |
| effector | a muscle of gland that responds to stimulaton |
| facilitation | subthreshold stimulation of a neuron makes it more responsive to further stimulation |
| ganglion | a mass of neuron cell bodies, usually outside the central nervous system |
| myelin | fatty material that forms a sheathlike coverin garound some nerve fibers |
| neurilemma | sheath formed from Schwann cells on the outside of some nerve fibers |
| neurotransmitter | chemical that an axon end secretes to stimulate a muscle fiber to contract or a neuron to fire an impulse |
| parasympathetic nervous system | portion of the autonomic nervous system that arises from brain and sacral region of the spinal cord |
| peripheral nervous system | the portions of the nervous system outside the central nervous system |
| plexus | a network of interlaced nerves or blood vessels |
| reflex | a rapid, automatic response to a stimulus |
| sensory receptor | a specialized structure associated with the peripheral end of a sensory neuron specific to detecting a particular sensation and triggering a nerve impulse in response, which is transmitted to the central nervous system |
| somatic nervous system | motor pathways of peripheral nervous system that lead to the skin and skeletal muscles |
| sympathetic nervous system | portion of the autonomic nervous system that arises from the thoracic and lumbar regions of the spinal cord |
| synapse | the junction between the axon of one neuron and the dendrite or cell body of another neuron |
Combine with other sets
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