A 2-day-old premature

newborn develops a severe form of neonatal jaundice, which unfortunately has a

serious complication, the so-called kernicterus. It is essentially damage of

the brain nuclei, especially the basal ganglia, by a high concentration of a

compound known as unconjugated bilirubin, which causes the aforementioned

jaundice. This condition is caused by the immaturity of the blood-brain

barrier, which is not yet able to fulfill its function as a barrier, and

bilirubin reaches the nervous tissue through it. In older children and adults,

this condition no longer occurs thanks to a mature and functional blood-brain

barrier. What parts make up this barrier?

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 group of students is reviewing muscle

tissue before a test and come across a question on which they completely disagree. Can you help them sort out their disagreement? It is all about the

statement that cardiomyocytes, the cells of the heart muscle, have only the

classical ability to contract. Others claim that these cells have other

functions in addition to this one. Which of these four statements is closest to

the truth?

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 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

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?