Nervous system

5. the part of the brain that coordinates the actions of the muscles and helps maintain balance
8. a cell that carries messages through the nervous system.
9. the thick column of nerve tissue that is enclosed by the vertebrae and that links the brain to most of the nerves in the peripheral nervous system
10. a threadlike extension of a neuron that carries nerve impulses toward the cell body.
12. a neuron that carries nerve impulses from one neuron to the other
13. the brain and the spinal cord; the control center of the body
14. a message carried by a neuron.
15. the tiny space between the tip of an axon and the next structure

1. all the nerves located outside the central nervous system; connects the central nervous system to all parts of the body
2. the part of the central nervous system that is located in the skull and that controls most functions in the body
3. a neuron that sends an impulse to a muscle, causing the muscle to contract
4. the part of the brain that controls many body functions that occur automatically
6. a neuron that picks up stimuli from the internal or external environment and converts each stimulus into a nerve impulse
7. a threadlike extension of a neuron that carries nerve impulses away from the cell body.
11. an automatic response that occurs very rapidly and without conscious control
13. the part of the brain that interprets input from the senses, controls the movement of the skeletal muscles, and carries out complex mental processes