Question 1

Which part of the neuron is primarily responsible for receiving incoming signals from other neurons?

Accepted Answer

Dendrites

Question 2

What is the typical resting membrane potential of a neuron?

Accepted Answer

$$-70\ \mathrm{mV}$$

Question 3

If the voltage inside a neuron is $$60\ \mathrm{mV}$$ and the voltage outside is $$80\ \mathrm{mV}$$, what is the membrane potential?

Accepted Answer

$$-20\ \mathrm{mV}$$

Question 4

During the rising phase of the action potential, which ion primarily moves into the neuron?

Accepted Answer

Sodium ($$Na^+)$$

Question 5

What is the main function of the myelin sheath in axonal transmission?

Accepted Answer

To increase the speed of action potential propagation

Question 6

Which process allows action potentials to 'jump' from one node to the next in myelinated axons?

Accepted Answer

Saltatory conduction

Question 7

What happens to the membrane potential when sodium ions rush into the neuron during an action potential?

Accepted Answer

The cell becomes more positive (depolarized)

Question 8

Which stage of the action potential is characterized by the neuron being hyperpolarized?

Accepted Answer

Undershoot (afterpotential)

Question 9

What is the 'all-or-none' principle of action potentials?

Accepted Answer

Action potentials only occur if the membrane potential reaches threshold

Question 10

Which of the following best describes the refractory period?

Accepted Answer

A brief period during which another action potential cannot be generated

Question 11

What would likely happen to action potential transmission in an axon without myelination?

Accepted Answer

It would be slower and may fade

Question 12

Which equation correctly represents the calculation of membrane potential ($$V_m) $$given intracellular ($$V_{in}) $$and extracellular ($$V_{out}) $$voltages?

Accepted Answer

$$V_m = V_{in} - V_{out}$$

Question 13

A neuron is stimulated and its membrane potential changes from $$-70\ \mathrm{mV} to$$ $$+50\ \mathrm{mV}. $$What process is occurring?

Accepted Answer

Depolarization

Question 14

Which structure is the site where neurotransmitters are released to communicate with another neuron?

Accepted Answer

Synaptic cleft

Question 15

What is the primary role of potassium ($$K^+) $$ions during the falling phase of the action potential?

Accepted Answer

To repolarize the neuron by moving out of the cell

Question 16

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

Accepted Answer

Myelin allows action potentials to jump between nodes (saltatory conduction)

Question 17

A patient with multiple sclerosis experiences slowed neural transmission. Which neural structure is most likely damaged?

Accepted Answer

Myelin sheath

Question 18

Which of the following is NOT a direct consequence of the refractory period?

Accepted Answer

Allows neurons to fire at maximum frequency

Question 19

Which scenario best illustrates the concept of threshold in action potential generation?

Accepted Answer

A neuron fires an action potential only after depolarization reaches a specific voltage

Question 20

Which of the following best describes the direction of signal transmission in a typical neuron?

Accepted Answer

From dendrites to axon terminals

Neurons and Neural Transmission: Resting Potential, Action Potential, and Myelination

Guida di studio - Domande di pratica

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