A

35-year-old woman comes to a neurologist because she is suspected of having

multiple sclerosis. Unfortunately, further examination will confirm this

diagnosis. Multiple sclerosis is an autoimmune disease affecting the central

nervous system. This disease leads to loss of myelin in inflammatory areas and

diffuse loss of axons. Which type of cell is responsible for the production of

myelin and in which part of the central nervous system is it produced?

A 35-year-old man presents with a spastic-type of

paralysis in the

right lower extremity, visual impairment in his right eye, and fatigue. Magnetic resonance imaging (MRI) confirms areas of patchy demyelination in specific areas of the left cerebral hemisphere. The product of which of the following cells is specifically targeted in this condition?

A 36-year-old woman comes to the emergency department because

of a 4-week history of worsening headache, nausea, and vomiting. The

headache is worse at night. A CT scan of the brain shows a mass of

tissue in the third ventricle. The patient undergoes surgical excision of this

structure. Pathologic examination of the surgical specimen confirms that

the tumor originates from special cells lining the ventricle. How are

these cells called?

A 24-year-old man who lives in Africa presents

with muscle weakness in his legs. His physical exam demonstrates muscle

weakness in all limbs, but his legs are most affected. Testing (polymerase

chain reaction, PCR) confirms poliovirus in his cerebrospinal fluid. Poliovirus

mainly affects second motor neurons of the corticospinal tract and, therefore,

will affect cells whose cell bodies are located in which of the following?