Question 1

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

Accepted Answer

They provide insulation for neurons by forming myelin sheaths.

Question 2

A patient suffers from a demyelinating disease affecting the CNS. Which of the following is most likely impaired as a result?

Accepted Answer

Saltatory propagation of action potentials along axons.

Question 3

Which type of neuron is most commonly found in the human body and is responsible for controlling skeletal muscles?

Accepted Answer

Multipolar neuron

Question 4

During an action potential, which event occurs immediately after the membrane potential reaches $$+30\ \mathrm{mV}$$?

Accepted Answer

Potassium channels open, initiating repolarization.

Question 5

A toxin blocks voltage-gated sodium channels on a neuron's axon. What is the most immediate effect on the neuron's ability to transmit signals?

Accepted Answer

The neuron cannot initiate an action potential.

Question 6

Which of the following best explains why myelinated axons conduct action potentials faster than unmyelinated axons?

Accepted Answer

Action potentials jump between nodes of Ranvier in saltatory conduction.

Question 7

A person touches a hot stove and quickly withdraws their hand. Which type of neuron is responsible for transmitting the sensory information from the hand to the CNS?

Accepted Answer

Unipolar neuron

Question 8

Which glial cell is primarily responsible for phagocytosis of pathogens and cellular debris in the CNS?

Accepted Answer

Microglia

Question 9

If the resting membrane potential of a neuron is $$-70\ \mathrm{mV}$$ and the threshold for action potential generation is $$-60\ \mathrm{mV}$$, what will happen if a stimulus depolarizes the membrane to $$-65\ \mathrm{mV}$$?

Accepted Answer

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

Question 10

Which of the following best describes the role of excitatory neurotransmitters at a chemical synapse?

Accepted Answer

They promote the generation of action potentials by depolarizing the postsynaptic membrane.

Question 11

Which of the following is TRUE regarding the refractory period of a neuron?

Accepted Answer

During the relative refractory period, only a suprathreshold stimulus can trigger another action potential.

Question 12

Which of the following best explains why potassium ions ($$K^+) $$leave the neuron more easily than sodium ions ($$Na^+) at $$rest?

Accepted Answer

There are more leak channels for $$K^+$$ than for $$Na^+ in $$the neuronal membrane.

Question 13

A patient is diagnosed with a disorder affecting Schwann cells. Which of the following is most likely to be impaired?

Accepted Answer

Myelination of axons in the peripheral nervous system (PNS)

Question 14

Which of the following is a characteristic of Type A nerve fibers?

Accepted Answer

They are myelinated, have a large diameter, and conduct impulses rapidly.

Question 15

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

Accepted Answer

An action potential is either triggered completely or not at all, depending on whether threshold is reached.

Question 16

Which of the following scenarios best illustrates the function of proprioceptors?

Accepted Answer

Sensing the position and movement of your arm during a tennis serve.

Question 17

Which of the following is TRUE about graded potentials?

Accepted Answer

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

Question 18

A neuron receives simultaneous excitatory and inhibitory inputs. Which structure integrates these signals to determine if an action potential will be generated?

Accepted Answer

Axon hillock

Question 19

Which of the following best describes the effect of norepinephrine (NE) released at an adrenergic synapse?

Accepted Answer

It has an excitatory and depolarizing effect on the postsynaptic membrane.

Question 20

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

Accepted Answer

Chemical synapses transmit signals across a synaptic cleft using neurotransmitters.

Nervous Tissue and Neural Physiology: Structure and Function

Study Guide - Practice Questions

Study Guide - Flashcards