The reason for rapid conduction of impulses along myelinated nerve fibers is that they have( ) A: long axons B: thick axons C: many synaptic vesicles in the axons D: clefts of Schmidt and Lantermann E: nodes of Ranvie

Oligodendrocytes make myelin, a fatty substance that insulates nerve axons and speeds the conduction of impulses along nerve fibers.

The axons and dendrites that are coated with a myelin sheath are called ( ). A: Neurite B: Nerve C: Nerve ending D: Nerve fiber

The submandibular ganglion contains preganglionic parasympathetic axons from which cranial nerve? A: oculomotor nerve B: trigeminal nerve C: facial nerve D: hypoglossal nerve E: vagus nerve

What are NOT the correct descriptions of the postganglionic fibers? A: They are the axons of the postganglionic neurons. B: They may surround the artery as parts of nerve plexus. C: They may accompany with the corresponding spinal nerve to the peripheral blood vessles, sweat gland and arrector pilli muscles. D: They may relay in corresponding ganglion. E: They may terminate directly in certain organs.

Oligodendrocytes make myelin, a fatty substance that insulates nerve axons and speeds the conduction of impulses along nerve fibers. A: 少突胶质细胞能制造髓磷脂。髓磷脂是一种脂类物质，能使轴突绝缘并能使冲动沿着神经纤维快速传导。 B: 少突胶质细胞能制造髓磷脂。髓磷脂是一种能使轴突绝缘并能使冲动沿着神经纤维快速传导的脂类物质。 C: 少突胶质细胞能制造髓磷脂。髓磷脂是一种脂类物质，它包裹着轴突, 能使冲动沿着神经纤维快速传导。 D: 少突胶质细胞能制造包裹着轴突使冲动沿着神经纤维快速传导的一种脂类物质 — 髓磷脂。