Nervous System Word Search (9.1-9.12) Name ________________________________

1. The voluntary muscles are controlled by the _______________________________nervous system.
2. The ____________________________ enlargement of the spinal cord supplies nerves to the lower body.
3. Neurons are composed of a network of fine threads called _________________________________
4. ______________________________are cells found between neurons and blood vessels.
5. Neurons consist of a cell body, axons, and ______________________________
6. The ____________________________________ nervous system consists of the brain and spinal cord
7. A nerve impulse starts at the dendrite then travels to the _______________________
8. White matter is composed of axons that are sheathed in ______________________________
9. Once the threshold stimulus is received, _____________________________ channels open
10. The spinal cord originates at the brain, passes through the ______________ magnum and then descends to the lumbar vertebrae
11. When an ____________________ potential is reached, sodium diffuses inward, and the membrane becomes depolarized.
12. The junction between two communicating neurons is called the ______________________________
13. The ____________________________________________that stimulates muscles cells is called acetylcholine.
14. The _________________________arc refers to a simple nerve pathway that would be involved with involuntary actions (like knee-jerk, or withdrawal)
15. The __________________________ mater is the outermost layer of the meninges.
16. __________________________________cells help destroy bacterial cells and cellular debris.
17. There are 31 pairs of ____________________________ nerves.
18. Tracts that carry sensory information to the brain are called ________________________________ tracts.
19. Membranes called ________________________________ are located between bone and the soft tissue of the nervous system.
20. Gaps in the myelin sheath are called Nodes of _________________________________