Question 1

Which of the following best describes the function of Schwann cells in the peripheral nervous system?

Accepted Answer

They produce myelin sheaths around axons.

Question 2

A patient suffers a laceration to the forearm, damaging several peripheral nerves. Which process is most likely to occur if the cell bodies remain intact and Schwann cells are functional?

Accepted Answer

Axonal regeneration via formation of a regeneration tube.

Question 3

Which of the following statements about the resting membrane potential of a neuron is correct?

Accepted Answer

It is maintained by the active transport of Na+ out and K+ in via the Na+/K+ pump.

Question 4

Which type of neuron is most likely to be found in the retina of the eye and is characterized by having one dendrite and one axon?

Accepted Answer

Bipolar neuron

Question 5

During an action potential, which event occurs immediately after the membrane potential reaches threshold at the axon hillock?

Accepted Answer

Voltage-gated sodium channels open, allowing Na+ to rush into the cell.

Question 6

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

Accepted Answer

The myelin sheath allows the impulse to 'jump' from one node of Ranvier to the next.

Question 7

A toxin blocks the reuptake of neurotransmitters at the synaptic cleft. What is the most likely effect on synaptic transmission?

Accepted Answer

Neurotransmitter remains in the cleft longer, prolonging the postsynaptic response.

Question 8

Which of the following is a function of astrocytes in the central nervous system?

Accepted Answer

Regulating nutrient and ion concentrations and forming the blood-brain barrier

Question 9

A neuron receives both excitatory and inhibitory inputs. If the sum of all graded potentials at the axon hillock reaches $$-55\ \mathrm{mV}$$, what will occur?

Accepted Answer

An action potential will be generated.

Question 10

Which of the following best describes the 'all-or-none' principle of action potentials?

Accepted Answer

If threshold is reached, the neuron fires a full action potential; if not, it does not fire at all.

Question 11

Which of the following is a correct sequence of events during synaptic transmission at a chemical synapse?

Accepted Answer

Action potential arrives at synaptic knob → Ca$$^{2+}$$ influx → neurotransmitter release → binding to postsynaptic receptors

Question 12

Which of the following is a property of graded potentials but NOT action potentials?

Accepted Answer

They can summate and vary in amplitude.

Question 13

A patient is exposed to Clostridium tetani, which uses fast axonal transport to reach neuron cell bodies. Which direction does this transport occur and at what approximate speed?

Accepted Answer

Retrograde at 200-400 mm/day

Question 14

Which of the following neurotransmitters is generally inhibitory in the central nervous system?

Accepted Answer

GABA

Question 15

Which of the following best describes the role of the Na$$^+/K$^+$$ pump in maintaining the resting membrane potential?

Accepted Answer

It actively transports 3 Na$$^+$$ out and 2 K$$^+ in$$, maintaining a negative interior.

Question 16

Which of the following is a characteristic of the autonomic nervous system?

Accepted Answer

It regulates involuntary functions such as cardiac muscle, smooth muscle, and glands.

Question 17

A neuron in the CNS receives input from multiple presynaptic neurons at the same time, resulting in a combined effect. This is an example of:

Accepted Answer

Spatial summation

Question 18

Which of the following best explains why CNS axons do not typically regenerate after injury?

Accepted Answer

Oligodendrocytes produce growth-inhibiting proteins and astrocytes form scar tissue.

Question 19

Which of the following is a correct description of a reflex arc?

Accepted Answer

An involuntary pathway involving a sensory receptor, sensory neuron, interneuron, motor neuron, and effector.

Nervous Tissue: Structure, Function, and Physiology

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