Across
- 2. ____________ nervous system: includes all parts of the nervous system outside the CNS
- 4. __________ matter: unmyelinated fibers and cell bodies
- 7. ____________ nervous system: regulates involuntary movements in body
- 8. __________ matter: dense collections of myelinated fibers
- 10. gap between neurons
- 11. ends of neurons, contain neurotransmitters
- 12. rapid, involuntary response to stimulus
- 13. ____________ nervous system: allows voluntary movement of skeletal muscles
- 15. "nerve glue", supporting cells of nervous system
- 17. ___________ nervous system: consists of brain and spinal cord
- 18. nerve cell
Down
- 1. chemical messengers that transmit impulses between neurons
- 3. collection of cell bodies
- 5. specialized cells that form the myelin sheath
- 6. treelike extensions that receive signal
- 9. sheath that protects and insulates neurons and increases speed of impulses
- 14. metabolic center of neuron, contains nucleus
- 16. tail-like extension of the cell body that sends signal away from neuron