TBI Physiology of the Brain 4

Question 1

Which process describes excess glutamate release leading to neuronal death after TBI?

Accepted Answer

Excitotoxicity

Answer

Excess glutamate overstimulates receptors, causing calcium influx and cell injury, a key secondary injury mechanism.

Question 2

Which cells produce myelin in the central nervous system?

Accepted Answer

Oligodendrocytes

Answer

Oligodendrocytes myelinate CNS axons, while Schwann cells do so in the peripheral nervous system.

Question 3

Which glial cells are most involved in supporting the blood-brain barrier and buffering extracellular potassium?

Accepted Answer

Astrocytes

Answer

Astrocytes support the blood-brain barrier, regulate ions and clear neurotransmitters.

Question 4

What injury mechanism primarily causes diffuse axonal injury?

Accepted Answer

Rotational acceleration-deceleration forces that shear axons

Answer

Rapid rotational acceleration and deceleration stretch and shear axons throughout the white matter.

Question 5

Which substrate is the brain's primary energy source under normal conditions?

Accepted Answer

Glucose

Answer

The brain relies mainly on glucose and uses roughly 20% of the body's oxygen despite being about 2% of its weight.

TBI - Traumatic Brain Injury Certification Practice Test