A 30-year-old man is brought to the emergency

department 15 minutes after he fell off the

ladder. On arrival, he is unresponsive to verbal and painful stimuli. His pulse

is 70/min and his blood pressure is 130/85 mmHg. A CT scan of the head shows a fracture in the

anterior cranial fossa and a 1.5 cm laceration

in the left anterior frontal gyrus. Which of the following would be the most common cell type in the scar at the injured region of

the frontal lobe?

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?

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?