Question 1

What accounts for the action potential moving down the axon at a constant speed?

Accepted Answer

The all-or-none law explains that once an action potential is triggered, it moves down the axon at a constant speed without decreasing in intensity.

Question 2

The membrane of the axon has the unique ability to:

Accepted Answer

The membrane of the axon has chemical gates (ion channels) that can open and close to allow certain ions to pass through, which is essential for the transmission of electrical signals along the axon. This process is known as depolarization and repolarization. Therefore, the membrane of the axon can open and close its chemical gates. The other options are not accurate descriptions of the membrane of the axon.

Question 3

If the positive sodium ions rush inside the axon,the axon will:

Accepted Answer

Positive sodium ions rushing inside the axon cause depolarization of the cell membrane, which can reach a critical threshold and trigger an action potential - a rapid, temporary change in the electrical potential of the axon. Therefore, the correct answer is D - experience an action potential.

Question 4

Opposite-charged ions ____ and like-charged ions ____.

Accepted Answer

Opposite-charged ions attract each other, while like-charged ions repel each other.

Question 5

If neurotransmitters could talk,what would they say about where they are stored?

Accepted Answer

Neurotransmitters are stored in tiny sacs called vesicles located in the end bulb or synaptic terminal of neurons.

Question 6

There is new research that involves replacing damaged neurons with:

Accepted Answer

Transplanted fetal tissue or embryonic stem cells have shown promise in replacing damaged neurons and restoring function in certain neurological conditions such as Parkinson's disease or spinal cord injuries. The use of tiny computers or transplanted tubes from monkeys is not currently a viable option for replacing damaged neurons. Computerized sodium pumps may have some therapeutic potential, but there is not yet enough research to determine their effectiveness in replacing damaged neurons.

Question 7

During an action potential,the inside of the axon becomes ____ and the outside becomes ____.

Accepted Answer

During an action potential, the inside of the axon becomes positive due to the influx of sodium ions, while the outside becomes negative relative to the inside.

Question 8

Why does MS disrupt the messages between the body and brain?

Accepted Answer

MS attacks the myelin sheath that surrounds the brain cells in the CNS, disrupting the messages between the body and brain.

Question 9

According to your textbook,new research on the regeneration of neurons includes:

Accepted Answer

The use of fetal tissue or embryonic stem cells has shown promise in helping to regenerate neurons in the central nervous system. This is because these cells have the ability to differentiate into various types of cells, including neurons, and can potentially replace the damaged or dead neurons in the affected area. While the other options may have some potential in certain cases, they are not as widely studied or effective as the use of stem cells.

Question 10

A psychology instructor is lecturing on the processes and mechanisms of messages in the nervous system.She has come to the part on the action potential.Which example should she use to illustrate the idea of a nerve impulse?

Accepted Answer

"The Wave" at a sports stadium involves a sequential and coordinated movement of sections of fans standing up and then sitting down, similar to the sequential depolarization and repolarization of neurons during an action potential. This analogy can help students understand how a nerve impulse travels along a neuron. Options A, C, and D do not accurately represent the concept of action potentials in the nervous system.

Question 11

A tiny electrical current generated in the axon is called a(n)

Accepted Answer

The tiny electrical current generated in the axon is known as an action potential.

Question 12

If the stimulation is strong enough,the neuron's chemical gates ____ and ____ will come into the neuron.

Accepted Answer

When the stimulation is strong enough, the neuron's chemical gates will open and positive sodium ions will come into the neuron, causing depolarization of the cell.

Question 13

A synapse is the:

Accepted Answer

A synapse is the small space between the end bulb of a neuron and its neighboring organ, muscle, or cell body where communication between neurons occurs. Choices A, C, and D are not accurate definitions of a synapse.

Question 14

When a neuron is in a resting state,the majority of the particles in the fluid surrounding the neuron are:

Accepted Answer

In the resting state of a neuron, the fluid outside the neuron (extracellular fluid) has a high concentration of positive sodium ions (Na+). This creates a difference in ion concentration across the neuron's membrane, which is crucial for the neuron's ability to generate an action potential.

Question 15

During a class meeting,a student asks the psychology professor to define a nerve impulse.Before the professor can open his mouth to answer,you remember the definition,which is:

Accepted Answer

A nerve impulse is accurately described as a series of individual action potentials that occur segment by segment down the axon, rather than a simultaneous electrical surge. This process allows for the rapid transmission of signals along the neuron.

Question 16

As you're waiting to visit a friend in the hospital,you overhear a physician talking to a patient's parents.You don't hear the entire conversation,but only bits and pieces.There is something about an accident and a question regarding nerves reattaching.The physician replied that the nerves do have the ability to regrow.From your education in psychology,you guess that the nerves were probably part of the:

Accepted Answer

The peripheral nervous system includes the nerves that extend from the spinal cord and brain to the rest of the body. Injuries to these nerves are sometimes able to heal and regenerate, unlike injuries to the central nervous system (such as the spinal cord itself) or other parts of the brain (like the limbic system). The mention of nerves regrowing suggests that the injury might involve the peripheral nervous system.

Question 17

The nerves that make up the body,except the brain and spinal cord,comprise the:

Accepted Answer

The peripheral nervous system includes all the nerves outside of the brain and spinal cord, such as the cranial nerves, spinal nerves, and autonomic nervous system. The central nervous system includes the brain and spinal cord. The terms primary and secondary nervous system are not commonly used in neuroscience.

Question 18

End bulbs release neurotransmitters into the:

Accepted Answer

End bulbs, also known as axon terminals, release neurotransmitters into the synapse between two neurons, allowing for communication between them. The other options listed (cell body, myelin sheath, and axon) do not typically play a role in neurotransmitter release.

Question 19

The fact that John Thompson can use his arms but Montel Williams is unlikely to be cured of MS illustrates the difference between:

Accepted Answer

John Thompson's ability to use his arms indicates that he has intact motor neurons and muscles, which are part of the peripheral nervous system. Montel Williams, on the other hand, has multiple sclerosis which affects the central nervous system, specifically the myelin covering of nerve cells, which can result in muscle weakness and loss of control. This highlights the difference between the peripheral nervous system and the central nervous system.

Question 20

Sylvester severed a toe in an accident with his lawn mower.If the toe is not too damaged,what is the chance that the toe can be reattached to his foot?

Accepted Answer

Nerves in the peripheral nervous system have the capacity to regenerate, which means that if the toe is not too damaged, there is a good chance that it can be reattached to Sylvester's foot. Nerves in the central nervous system do not have the same capacity for regeneration, which rules out option B. Option D is incorrect because the autonomic nervous system controls involuntary actions such as heart rate and digestion, and has no role in controlling the movement of limbs or fingers. Option A is also incorrect because while nerves in the peripheral nervous system may not regenerate as quickly or completely as other tissues, they can still regenerate to some extent.

Quiz 3: Brains Building Blocks