Question

Which of these statements about myelination in neurons is/are correct? Select True or False for each statement.
T/FIt speeds propagation by increasing the density of voltage-gated channels all along the axon.
T/FMultiple sclerosis is characterized by disrupted myelination of certain neurons in the central nervous system.
T/FIt speeds propagation by preventing cations from leaking out across the membrane as they spread down the axon.
T/FIt is more commonly observed in vertebrates than in invertebrates.

Accepted Answer

Understand the role of myelination in neurons: Myelination is the process by which a fatty layer, called myelin, accumulates around nerve fibers (axons). This layer acts as an insulator and is crucial for the efficient transmission of electrical signals along the neuron. Evaluate the first statement: 'It speeds propagation by increasing the density of voltage-gated channels all along the axon.' Myelination actually reduces the need for voltage-gated channels along the axon, concentrating them at the nodes of Ranvier, which are gaps in the myelin sheath. This allows for faster signal transmission through saltatory conduction. Consider the second statement: 'Multiple sclerosis is characterized by disrupted myelination of certain neurons in the central nervous system.' Multiple sclerosis is indeed a disease where the immune system attacks the myelin sheath in the central nervous system, leading to disrupted signal transmission. Analyze the third statement: 'It speeds propagation by preventing cations from leaking out across the membrane as they spread down the axon.' Myelination prevents the leakage of ions, including cations, across the axonal membrane, which helps maintain the strength and speed of the electrical signal. Review the fourth statement: 'It is more commonly observed in vertebrates than in invertebrates.' Myelination is a characteristic more commonly found in vertebrates, as it is a key adaptation for efficient nerve signal transmission in larger and more complex nervous systems.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Myelination and Signal Propagation

Multiple Sclerosis and Myelination

Myelination in Vertebrates vs. Invertebrates