Exam 12: Cranial Nerves and Their Nuclei

After swim practice a 22-year-old man decides to work on his diving technique. During one of his dives his head strikes the bottom of the pool, hyperextending his neck. He is unable to move, and his teammates find him floating motionless in the pool. A magnetic resonance scan indicates a lesion at the cervical level of the spinal cord. The transected axons distal to the cell body will most likely undergo which of the following?

Which of the following connective tissue layers of a peripheral nerve contains the blood supply to the nerve?

Which of the following is not considered a structure of the cytoplasm?

Anterograde transport of materials via the microtubules from the soma to the synapse is facilitated by which of the following?

What is the difference in myelination of axons by Schwann cells versus myelination by oligodendrocytes?

Following an extensive liposuction procedure a 27-year-old woman notices that she no longer has tactile sensation around her abdomen. Her plastic surgeon explains to her that the nerves innervating the skin were probably damaged; however, sensation will most likely return over a period of time. Which of the following is the most accurate estimate of peripheral nerve growth in one day?

Three weeks after implanting olfactory ensheathing cells into the injured spinal cord of a rat, a research scientist injects a retrograde label to trace neuronal connections through the lesion. Microscopic examination indicated no movement of the dye through the lesion because of scar tissue that had formed at the site of the injury. The scar tissue is most likely formed by which of the following cell types?

A 45-year-old woman is diagnosed with a disease that causes degeneration of neurons directly connecting photoreceptors to ganglion cells in the retina. Which of the following represents this cell type?

A newborn infant is diagnosed with phenylketonuria. The neonatologist prescribes a special diet for the baby and explains to the parents the importance of maintaining this diet in order to prevent mental retardation. In this patient abnormal development of which of the following structures will most likely lead to mental retardation?

Following the death of a patient with Alzheimer's disease, a neuropathologist examines several of her brain sections under the microscope. He notes a change in the cytoskeleton of several neurons. What is the most likely cause of this change?