Nervous System

3. the sequence of electrical changes that occurs in a portion of a nerve
7. sheath formed from Schwann cells on outside of some nerve fibers
10. nerve fiber that conducts nerve impulses away from neuron cell body
12. 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 sytem
13. functional connection between the axon of a neuron and the dendrite or cell body of another neuron or the membrane of another cell type
16. Nerve impulses arriving at the same neuron
17. process of a neuron that receives input from other neurons
20. portion of the autonomic nervous system that arises from the thoracic and lumbar regions of the spinal cord

1. the portions of the nervous system outside the central nervous system
2. a network of interlaced nerves or blood vessels
4. portion of the autonomic nervous system that arises from the brain and sacral region of the spinal cord
5. a mass of neuron cell bodies, usually outside the central nervous system
6. brain and spinal cord
8. spreading apart
9. chemical that an axon end secretes on an effector or another neuron
11. the part of the PNS that controls the glands and the muscles of the internal organs
14. subthreshold stimulation of a neuron that increases responsiveness to further stimulation
15. 3 protective membranes that surround the brain and spinal cord
18. body large granular body found in neurons, have ribosomes attached
19. rapid automatic response to a stimulus
21. a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses
22. motor pathways of the peripheral nervous system that lead to the skin and skeletal muscles
23. a muscle or gland that effects change in the body