The Nervous System

Across

1. bundle of neuronal processes (axons) outside the CNS.
4. the rounded structure that protrudes just below the midbrain, it is the area that is mainly fiber tracts, and has important nuclei involved in the control of breathing.
8. keeps the CNS constantly informed of events going on both inside and outside the body.
10. connect the motor and sensory neurons in neural pathways.
13. responsible for muscle coordination, balance, posture, and muscle tone.
14. the three connective tissue membranes covering and protecting the CNS structures.
17. a tough fibrous sheath that binds the fascicles together to form the cordlike nerve.
18. the section located below the cerebrum at the top of the brainstem and is responsible for conducting impulses between parts and for certain eye and auditory reflexes.
20. sensory receptors in the muscles and tendons that detect the amount of stretch, or tension, in skeletal muscles.
24. a delicate connective tissue sheath that surrounds neuron fibers.
25. neuron process that convey incoming messages (electrical signals) toward the cell body.
26. dendrite endings o the sensory neurons that are activated by specific changes occurring.
27. monitors health of nearby neurons and dispose of debris.
29. elevated ridges of tissues on the entire surface of the cerebral hemispheres.
32. neuron process that generates the nerve impulses and typically conduct them away from the cell body.
33. glia wrap their flat extensions (processes) tightly around the nerve fibers, producing fatty insulating covering called myelin sheaths.
34. is around the brain and cord that forms a watery cushion that protects the nervous tissue from trauma.
36. brain and spinal cord. acts as the integrating command centers o the nervous system.
37. important autonomic nervous system center because it plays a role in the regulation of body temperature, water balance, and metabolism.
39. transmit messages (nerve impulses) from one part of the body to another.
40. forms the roof of the third ventricle.
41. encloses the shallow third ventricle of the brain.
42. regulates events that are automatic or involuntary, such as the activity of smooth and cardiac muscle and glands.
43. result of marked tissue destruction and always result in a coma lasting from hours to a lifetime due to injury to the reticular activating system.

Down

2. are rapid, predictable and involuntary response to stimuli.
3. tiny gap that separates the axon terminal from the next neuron.
5. allows us to voluntarily control our skeletal muscles.
6. a white, fatty lipid substance that covers most long nerve fibers.
7. it processes and interprets the sensory input and decides what should be done at each moment.
9. deeper grooves that separate large regions of the brain.
11. shallow grooves of the cerebral hemispheres that separate gyri.
12. a coarser connective tissue that wraps and binds groups of neuron fibers.
15. includes many types of cells that generally support, insulate, and protect the delicate neurons.
16. the largest part of the brain; consists of right and left cerebral hemispheres.
19. slight brain injury where victim may be dizzy or lose consciousness briefly.
20. plasma membrane of a resting/inactive neuron.
21. the outflow of positive ions (k+) from the cell restores the electrical conditions at the membrane to the polarized, or resting state.
22. inward rush of sodium ions changes the polarity of the neurons membrane at that site.
23. or interbrain that sits atop the brain stem and is enclosed by the cerebral hemispheres.
28. a condition where the head is enlarged as the brain increases in size.
30. a bundle of nerve fibers bound together by connective tissue.
31. carries impulses from the CNS to effector organs, the muscles and the glands.
35. consists of the nerves that extend from the brain and spinal cord.
38. brace neurons and anchor them to their nutrient supply lines.