Question

1. astrocytes are thought to provide structural support within the nervous system. true false 38. since the response of a nerve fiber is all - or - none, a greater intensity of stimulus does not produce a stronger impulse. true false 39. interneurons are specialized to carry impulses from receptor cells into the brain or spinal cord. true false 40. nodes of ranvier occur between adjacent neurons. true false 41. convergence involves two or more incoming fibers converging on a single neuron, whereas divergence involves impulses leaving a neuron and passing into several output fibers. true false 42. a mixed nerve is a nerve composed of a mixture of different neuroglial cells. true false 43. the cells within the nervous system that fills spaces and give support to neurons are called ______ ____. 44. sheaths of ____ cells often enclose the larger axons outside of the brain and spinal cord. 45. the difference in electrical charge between the inside and outside of a polarized nerve cell membrane is called the ____ ____. 46. a(n) ______ is the junction between the parts of two neurons.

Explanation:

1. Astrocytes are glial cells that provide structural support in the nervous system.
2. The all - or - none law states that a nerve fiber either fires completely or not at all, so a stronger stimulus doesn't make a stronger impulse.
3. Interneurons are in the central nervous system and connect neurons, not carry impulses from receptor cells (sensory neurons do that).
4. Nodes of Ranvier are on a single axon (between Schwann cells), not between adjacent neurons.
5. Convergence is multiple fibers to one neuron, divergence is one neuron to multiple fibers.
6. A mixed nerve has both sensory and motor neurons, not neuroglial cells.
7. Neuroglial cells (glial cells) fill spaces and support neurons.
8. Schwann cells form myelin sheaths around axons outside the CNS.
9. The resting potential is the electrical charge difference across a polarized nerve cell membrane.
10. A synapse is the junction between two neurons.

Answer:

1. True
2. True
3. False
4. False
5. True
6. False
7. neuroglial cells
8. Schwann
9. resting potential
10. synapse