Final answer:
Most axons in the central nervous system are not able to regenerate following injury; this statement is false. CNS regeneration is restricted due to several inhibitory factors, in contrast to the PNS where some regeneration is possible.
Step-by-step explanation:
The answer to the student's question is B. False. Most axons in the central nervous system (CNS) are not capable of regeneration following injury. Unlike the peripheral nervous system (PNS), where axons can regrow under certain conditions, the CNS has a limited capacity for regeneration. This is due to a combination of factors including the presence of inhibitory molecules in the CNS myelin, a lack of growth-promoting factors, and the formation of scar tissue which can create a physical barrier to axon regrowth.
As for the additional questions:
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- True or False. Glial cells produce action potentials: False. Glial cells do not generate action potentials; they support neurons in various ways, such as the oligodendrocytes in the CNS that myelinate axons.
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- True or False. The spinal cord consists of white matter only: False. The spinal cord is composed of both white matter and gray matter.
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- True or False. Axons may be more than a meter long in adult humans: True. Some axons, such as those extending from the spinal cord to the feet, can be over a meter long in adults.
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- If a person has a stroke and as a result has trouble using language correctly, it is likely that the left hemisphere of their brain was damaged. This hemisphere is typically associated with language functions in the majority of right-handed individuals and many left-handed individuals.