Voltage-gated Na\textsuperscript{+} channels open, causing rapid depolarization.

The differential permeability of the membrane to K\textsuperscript{+} and Na\textsuperscript{+}

Question 1

Which of the following best describes the difference between the central nervous system (CNS) and the peripheral nervous system (PNS)?

Accepted Answer

The CNS consists of the brain and spinal cord, while the PNS includes all neural tissue outside the CNS.

Question 2

A patient suffers a spinal cord injury that damages the oligodendrocytes. Which of the following is the most likely consequence?

Accepted Answer

Decreased myelination in the CNS, leading to slower action potential conduction.

Question 3

Which connective tissue sheath directly surrounds each individual nerve fiber (axon) in a peripheral nerve?

Accepted Answer

Endoneurium

Question 4

Which of the following best explains why most CNS neurons cannot divide and regenerate after injury?

Accepted Answer

CNS neurons lack centrioles, preventing mitosis.

Question 5

A neuron receives multiple excitatory postsynaptic potentials (EPSPs) in rapid succession at a single synapse. This is an example of:

Accepted Answer

Temporal summation

Question 6

Which of the following glial cells is responsible for forming the myelin sheath in the peripheral nervous system (PNS)?

Accepted Answer

Schwann cells

Question 7

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

Accepted Answer

Voltage-gated Na	extsuperscript{+} channels open, causing rapid depolarization.

Question 8

Which of the following best describes the difference between saltatory and continuous propagation of action potentials?

Accepted Answer

Saltatory propagation occurs in myelinated axons and is faster because the action potential jumps between nodes of Ranvier.

Question 9

Which of the following is a correct sequence of events during the formation of an action potential?

Accepted Answer

Depolarization, repolarization, hyperpolarization

Question 10

A neuron is exposed to a toxin that blocks voltage-gated K	extsuperscript{+} channels. What effect will this have on the action potential?

Accepted Answer

Repolarization will be delayed, prolonging the action potential.

Question 11

Which of the following best defines the absolute refractory period?

Accepted Answer

The period during which a second action potential cannot be initiated, regardless of stimulus strength.

Question 12

Which of the following is NOT a function of astrocytes in the CNS?

Accepted Answer

Forming myelin sheaths around axons

Question 13

Which of the following factors contributes most to the resting membrane potential of a neuron?

Accepted Answer

The differential permeability of the membrane to K	extsuperscript{+} and Na	extsuperscript{+}

Question 14

A patient is diagnosed with a disease that destroys Schwann cells. Which of the following symptoms would you expect?

Accepted Answer

Slowed nerve conduction in the PNS

Question 15

Which of the following best describes an inhibitory postsynaptic potential (IPSP)?

Accepted Answer

A graded hyperpolarization of the postsynaptic membrane

Question 16

Which type of gated channel opens in response to a specific chemical binding to it?

Accepted Answer

Ligand-gated channel

Question 17

A neuron receives both EPSPs and IPSPs at the same time from different synapses. What is this process called?

Accepted Answer

Spatial summation

Question 18

Which of the following best explains the difference between a chemical gradient and an electrical gradient across a neuron's membrane?

Accepted Answer

A chemical gradient is due to differences in ion concentration, while an electrical gradient is due to differences in charge.

Question 19

Which of the following is the correct order of connective tissue sheaths from innermost to outermost in a peripheral nerve?

Accepted Answer

Endoneurium, perineurium, epineurium

Question 20

Which of the following best describes how information travels from a presynaptic cell to a postsynaptic cell at a chemical synapse?

Accepted Answer

Neurotransmitters are released from the presynaptic terminal, diffuse across the synaptic cleft, and bind to receptors on the postsynaptic membrane.

Chapter 11: Nervous Tissue – Structure, Function, and Communication

Study Guide - Practice Questions