Question 1

Which of the following best describes the main functional divisions of the peripheral nervous system (PNS)?

Accepted Answer

The PNS is divided into the sensory (afferent) and motor (efferent) divisions, which respectively convey impulses to and from the CNS.

Question 2

A patient is diagnosed with multiple sclerosis (MS). Which of the following best explains the physiological basis for the slowed nerve conduction observed in this disease?

Accepted Answer

MS destroys the myelin sheaths in the CNS, resulting in hardened lesions called scleroses and impaired saltatory conduction.

Question 3

Which of the following is a correct sequence of events during the generation of an action potential in a neuron?

Accepted Answer

Resting state → Depolarization → Repolarization → Hyperpolarization

Question 4

Which of the following best describes the role of astrocytes in the central nervous system?

Accepted Answer

Astrocytes support and brace neurons, and are the most abundant neuroglia in the CNS.

Question 5

A neuron receives a strong stimulus that opens gated ion channels, resulting in a localized change in membrane potential that does not travel far. What is this phenomenon called?

Accepted Answer

Graded potential

Question 6

Which of the following equations best represents the Nernst equation for calculating the equilibrium potential ($$E_{ion}) $$for a particular ion across a membrane?

Accepted Answer

$$E_{ion} = \frac{RT}{zF} \ln \left( \frac{[ion]_{out}}{[ion]_{in}} \right)$$

Question 7

Which of the following statements about the myelin sheath is TRUE?

Accepted Answer

The myelin sheath is a segmented, fatty substance that surrounds most long or large-diameter axons and is formed by Schwann cells in the PNS.

Question 8

A researcher is studying a neuron that has one axon and two dendrites. According to structural classification, this neuron is:

Accepted Answer

Multipolar

Question 9

Which of the following best explains why action potentials are considered 'all-or-none' phenomena?

Accepted Answer

Once threshold is reached, an action potential will fire completely; if threshold is not reached, no action potential occurs.

Question 10

Which of the following is a key difference between chemical and electrical synapses?

Accepted Answer

Electrical synapses are joined by gap junctions and allow rapid, bidirectional communication, while chemical synapses use neurotransmitters and are typically unidirectional.

Question 11

A patient has a loss of function in oligodendrocytes. Which of the following would most likely be affected?

Accepted Answer

Insulation of CNS axons by myelin sheaths

Question 12

During the repolarization phase of an action potential, which of the following occurs?

Accepted Answer

Voltage-gated K$$^+$$ channels open and K$$^+$$ exits the cell, making the membrane potential more negative.

Question 13

Which of the following best describes the function of ependymal cells in the CNS?

Accepted Answer

They line the central cavities of the brain and spinal cord, forming a barrier between cerebrospinal fluid and tissue fluid.

Question 14

Which of the following is TRUE regarding the resting membrane potential of a typical neuron?

Accepted Answer

It is approximately $$-70\ \mathrm{mV}$$ and is generated by differences in ionic composition and membrane permeability.

Question 15

Which of the following best describes the function of the axon hillock?

Accepted Answer

It is the cone-shaped area of the neuron where the axon originates and where action potentials are typically initiated.

Question 16

A graded potential in a neuron is most likely to occur at which part of the cell?

Accepted Answer

Dendrites and cell body (soma)

Question 17

Which of the following best explains why myelinated axons conduct impulses faster than nonmyelinated axons?

Accepted Answer

Myelin sheaths allow action potentials to jump between nodes of Ranvier in a process called saltatory conduction.

Question 18

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

Accepted Answer

Regulating involuntary activities of smooth muscle, cardiac muscle, and glands

Question 19

A neuron is classified as 'bipolar.' Which of the following is most likely TRUE about this neuron?

Accepted Answer

It has two processes (one axon and one dendrite) and is found in the retina and olfactory mucosa.

Fundamentals of the Nervous System and Nervous Tissue (Chapter 11) – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards