Nervous system

4. provide nourishment to neurons
6. cranial and spinal nerves
7. short, branched extensions of a nerve cell
8. involuntary portion of the nervous system
13. brain and spinal cord
14. gap between two nerve cells where the two neurons communicate
16. a gap in the myelin sheath of a nerve
18. regions containing many myelinated axons
19. multipolar neurons that conduct impulses from the CNS to peripheral effectors (muscles or glands)
23. chemical messengers that travel and transmit signals between neurons
24. regions of unmyelinated axons
25. cable-like bundle of nerve fibers that transmit electrochemical impulses

1. cells that insulate axons with myelin to speed up nerve signals
2. forms a sheath that allows electrical impulses to transmit quickly along nerve cells
3. when there are 2 processes extending from the cell body (a dendrite and an axon) it is ____
5. the neuron that receives the impulse is a ____ neuron
9. when a neuron has many dendrites and one axon arising form the cell body a neuron is ___
10. the neuron that sends the impulse is a ____ neuron
11. the gap between neurons is called the synaptic __
12. neurons lying within the CNS that form links b/w other neurons
15. a specialized cell transmitting nerve impulses/ a nerve cell
17. long threadlike parts of a nerve along which impulses are conducted from the cell body to other cells
20. voluntary portion of the nervous system
21. type of neuron that conducts impulses from peripheral receptors to the CNS
22. when a neuron has only one process extending from the cell body it is ____