Question 1

Which glial cell type is primarily responsible for forming the myelin sheath in the central nervous system (CNS)?

Accepted Answer

Oligodendrocytes

Question 2

A patient presents with a loss of sensation in the skin over the lateral thigh. Which plexus is most likely involved?

Accepted Answer

Lumbar plexus

Question 3

During embryonic development, which structure gives rise to the central nervous system (CNS)?

Accepted Answer

Neural tube

Question 4

Which of the following best describes the function of the blood-brain barrier (BBB)?

Accepted Answer

It regulates the passage of substances between the blood and the brain, protecting neural tissue.

Question 5

Which equation correctly represents the resting membrane potential (RMP) of a typical neuron?

Accepted Answer

$$RMP \approx -70\ \mathrm{mV}$$

Question 6

A signal is transmitted from one neuron to another at a chemical synapse. Which process occurs first?

Accepted Answer

Action potential arrives at the axon terminal

Question 7

Which of the following is TRUE regarding the organization of white and gray matter in the spinal cord?

Accepted Answer

Gray matter forms the central 'butterfly' shape and contains neuron cell bodies.

Question 8

Which glial cell type is responsible for producing cerebrospinal fluid (CSF) in the CNS?

Accepted Answer

Ependymal cells

Question 9

A patient has damage to the dorsal root of a spinal nerve. Which function is most likely impaired?

Accepted Answer

Sensory input from the periphery

Question 10

Which of the following best describes the process of saltatory conduction?

Accepted Answer

Action potentials jump from one node of Ranvier to the next, increasing conduction speed.

Question 11

Which neurotransmitter is released at the neuromuscular junction (NMJ) to stimulate muscle contraction?

Accepted Answer

Acetylcholine

Question 12

During the development of the spinal cord, which layer forms the gray matter?

Accepted Answer

Mantle layer

Question 13

Which of the following is a correct sequence for the development of the neural tube?

Accepted Answer

Neural plate → Neural groove → Neural folds → Neural tube

Question 14

Which equation best describes the movement of ions during depolarization of a neuron?

Accepted Answer

$$Na^+_{out} \rightarrow Na^+_{in}$$

Question 15

A patient suffers a spinal cord injury at the level of the lumbar enlargement. Which function is most likely affected?

Accepted Answer

Motor and sensory function of the lower limbs

Question 16

Which of the following best explains why action potentials do not travel backward along an axon?

Accepted Answer

Voltage-gated sodium channels become inactivated after firing, creating a refractory period.

Question 17

Which structure in the spinal cord contains ascending sensory tracts?

Accepted Answer

Dorsal (posterior) columns

Question 18

Which of the following is a function of satellite cells in the peripheral nervous system (PNS)?

Accepted Answer

Providing nutrients to neuron cell bodies

Question 19

A reflex arc involves which correct sequence of events?

Accepted Answer

Sensory receptor activation → Sensory neuron → CNS integration → Motor neuron → Effector response

Nervous System I: Embryology and Early Development of the Spinal Cord

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