$$3\ \mathrm{Na}^+\ \text{out},\ 2\ \mathrm{K}^+\ \text{in}$$

Question 1

Which of the following best describes the difference in conduction between myelinated and unmyelinated axons?

Accepted Answer

Myelinated axons conduct impulses faster due to saltatory conduction, where the action potential jumps between nodes of Ranvier.

Question 2

Which equation correctly represents the movement of ions by the sodium-potassium pump at rest?

Accepted Answer

$$3\ \mathrm{Na}^+\ 	ext{out},\ 2\ \mathrm{K}^+\ 	ext{in}$$

Question 3

A neuron’s membrane potential moves from $$-90\ \mathrm{mV} to$$ $$+30\ \mathrm{mV}. $$Which ion is primarily responsible for this change?

Accepted Answer

$$\mathrm{Na}^+$$ flooding into the cell

Question 4

Which of the following is TRUE about graded potentials (GP) compared to action potentials (AP)?

Accepted Answer

Graded potentials vary in size and decay with distance, while action potentials are always the same size and do not decay.

Question 5

Which type of synapse allows for the fastest transmission of information between neurons?

Accepted Answer

Electrical synapse

Question 6

What is the effect of an excitatory postsynaptic potential (EPSP) on the postsynaptic neuron?

Accepted Answer

It causes depolarization, moving the membrane potential toward threshold.

Question 7

Which neurotransmitter is excitatory in skeletal muscle but inhibitory in cardiac muscle?

Accepted Answer

Acetylcholine

Question 8

If the frequency of excitatory signals increases at a synapse, which type of summation occurs?

Accepted Answer

Temporal summation

Question 9

Which of the following best describes the role of voltage-gated sodium channels in the generation of an action potential?

Accepted Answer

They open when the membrane potential reaches threshold, allowing $$\mathrm{Na}^+ to $$enter and depolarize the cell.

Question 10

Which group of nerve fibers transmits impulses at the fastest rate?

Accepted Answer

Group A fibers

Question 11

Which process describes the addition of graded potentials from multiple sources at the same time?

Accepted Answer

Spatial summation

Question 12

Which of the following is a correct statement about the all-or-none principle of action potentials?

Accepted Answer

Action potentials only occur if the membrane potential reaches threshold.

Question 13

Which neurotransmitter is mainly inhibitory in the central nervous system?

Accepted Answer

GABA

Question 14

What would happen to a neuron if its sodium/potassium pumps stopped working?

Accepted Answer

The neuron would lose its resting membrane potential and be unable to fire action potentials.

Question 15

Which type of neural processing is exemplified by a spinal reflex?

Accepted Answer

Serial processing

Question 16

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

Accepted Answer

It hyperpolarizes the postsynaptic membrane, moving it away from threshold.

Question 17

Which of the following is TRUE regarding the propagation of an action potential along a myelinated axon?

Accepted Answer

The action potential jumps from one node of Ranvier to the next, increasing conduction speed.

Question 18

Which of the following neurotransmitters can be either excitatory or inhibitory depending on the receptor it binds to?

Accepted Answer

Acetylcholine

Question 19

Which of the following is a real-life example of parallel processing in the nervous system?

Accepted Answer

Remembering multiple experiences when smelling freshly baked apple pie.

Nervous System & Nervous Tissue: Graded Potentials, Action Potentials, and Synaptic Transmission

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