Question 1

Which of the following best describes the role of oligodendrocytes in the central nervous system (CNS)?

Accepted Answer

They form myelin sheaths around axons, increasing the speed of nerve impulse transmission.

Question 2

A patient presents with muscle weakness and difficulty walking. Laboratory tests reveal demyelination of peripheral nerves. Which condition is most likely responsible?

Accepted Answer

Guillain-Barré syndrome

Question 3

Which structural classification of neuron is most commonly found in sensory pathways that carry information from the skin to the CNS?

Accepted Answer

Unipolar neuron

Question 4

During the generation of an action potential, which event is responsible for the rapid depolarization phase?

Accepted Answer

Opening of voltage-gated sodium channels

Question 5

Which equation best represents the change in membrane potential during depolarization?

Accepted Answer

$$V_{m} = V_{rest} + \Delta V_{Na^+}$$

Question 6

Which neurotransmitter is primarily excitatory at all neuromuscular junctions and is decreased in Alzheimer's disease?

Accepted Answer

Acetylcholine (ACh)

Question 7

A neuron is stimulated, but the membrane potential only reaches -65mV. What is the most likely outcome?

Accepted Answer

A graded potential will occur, but no action potential will be generated.

Question 8

Which of the following best explains why saltatory propagation is faster than continuous propagation?

Accepted Answer

Saltatory propagation allows action potentials to jump between nodes of Ranvier, bypassing myelinated regions.

Question 9

Which formula describes the relationship between the speed of nerve impulse transmission and axon diameter in myelinated fibers?

Accepted Answer

$$v \propto d$$

Question 10

A patient is given a drug that increases the binding of GABA to its receptors. What is the expected effect on neural activity?

Accepted Answer

Decreased anxiety and increased relaxation

Question 11

Which of the following is true regarding the 'all-or-none principle' of action potentials?

Accepted Answer

If threshold is reached, the neuron responds with a full action potential.

Question 12

Which type of neuroglia is responsible for myelination in the peripheral nervous system (PNS)?

Accepted Answer

Schwann cells

Question 13

Which neurotransmitter is associated with precise control of movement and is deficient in Parkinson's disease?

Accepted Answer

Dopamine (DA)

Question 14

What is the primary function of the autonomic nervous system?

Accepted Answer

Regulation of smooth muscle, cardiac muscle, and glands

Question 15

Which of the following best describes the process of repolarization during an action potential?

Accepted Answer

Efflux of K\+ ions

Question 16

A neuron receives both excitatory and inhibitory neurotransmitters at the same time. What determines whether an action potential will be generated?

Accepted Answer

The sum of graded potentials at the axon hillock reaching threshold

Question 17

Which of the following is a correct description of graded potentials?

Accepted Answer

They are local changes in membrane potential that decrease with distance from the stimulus.

Question 18

Which neurotransmitter is most likely to be increased by selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression?

Accepted Answer

Serotonin (5-HT)

Question 19

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

Accepted Answer

The refractory period prevents re-excitation of the membrane segment.

Question 20

Which equation best represents the resting membrane potential of a neuron?

Accepted Answer

$$V_{rest} \approx -70\ \mathrm{mV}$$

Nervous Tissue: Structure and Function in the Nervous System

Guida di studio - Domande di pratica

Study guide - Flashcard