Question 1

_______ will be recorded from a nerve cell whose membrane potential rises above threshold.
A) action potential
B) local potential
C) downward shift of the threshold of excitation
D) upward shift of the membrane threshold
E) long-term change in the membrane potential

Accepted Answer

An action potential will be recorded from a nerve cell whose membrane potential rises above threshold. An action potential is a brief electrical message that travels along the axon of a neuron, which occurs when the membrane potential rises above a certain level called the threshold.

Question 2

A scan shows that a particular substance has spread throughout the body via the bloodstream but has not entered the brain. This finding demonstrates the existence of
A) the blood-brain barrier.
B) blood efficacy.
C) medicine effects.
D) the lipid bilayer.
E) the doctrine of specific nerve energies.

Accepted Answer

The fact that the substance has spread throughout the body via the bloodstream but has not entered the brain indicates that there is a barrier that prevents substances from crossing from the blood into the brain. This barrier is known as the blood-brain barrier and is composed of specialized cells that tightly regulate what substances can enter the brain.

Question 3

Regrowth of a damaged axon can occur more readily in the peripheral nervous system than in the brain because
A) Schwann cells form barriers to axon regrowth.
B) Schwann cells form cylinders through which new axons can grow and reinnervate a target cell nerve cell.
C) Schwann cells generate a chemical signal that instructs nerve cells to die.
D) Astrocytes form cylinders through which new axons can grow and reinnervate a target cell nerve cell.
E) Oligodendroglia form barriers to axon regrowth.

Accepted Answer

Schwann cells in the peripheral nervous system can form a structure called a "bands of Büngner," which forms a cylinder through which new axons can grow and reinnervate a target cell nerve cell. In contrast, astrocytes in the brain do not form such structures, and there is evidence that they can actually inhibit axon regrowth after injury. Schwann cells may also release growth factors that promote axon regrowth.

Question 4

The normal order of activation during neuronal transmission is
A) axon -> dendrite -> cell body -> axon terminals.
B) axon terminals -> cell body -> axon -> dendrite.
C) dendrite -> cell body -> axon -> terminal button.
D) cell body -> axon -> dendrite -> axon terminal.
E) dendrite -> axon terminal -> cell body -> axon.

Accepted Answer

The normal order of activation during neuronal transmission is dendrite -> cell body -> axon -> terminal button. The dendrites receive signals, which are then transmitted to the cell body, where they are integrated. If the combined signals are strong enough, an action potential is initiated and then propagated down the axon to the terminal button, where neurotransmitters are released.

Question 5

The interior of a neuron at rest
A) has the same ionic concentrations as the outside.
B) is at the same voltage potential as the outside.
C) has a higher sodium concentration than outside.
D) is negatively charged relative to the outside.
E) has a lower potassium concentration than outside.

Accepted Answer

The interior of a neuron at rest is negatively charged relative to the outside. This is due to the distribution of ions across the cell membrane, with positively charged sodium and calcium ions being more concentrated outside the cell, and negatively charged potassium ions being more concentrated inside the cell. This creates an electrochemical gradient that favors the movement of potassium ions out of the cell and the movement of sodium and calcium ions into the cell, resulting in a negative resting membrane potential.

Question 6

As you study for your neuroscience exam, you feel a tickle on your arm. You look and see a large spider and you jerk your arm automatically. What might be the neural path for this action?
A) sensory neuron -> interneuron -> motor neuron -> muscle
B) interneuron -> sensory neuron -> motor neuron -> muscle
C) motor neuron -> sensory neuron -> interneuron -> muscle
D) sensory neuron -> motor neuron -> interneuron -> muscle
E) motor neuron -> interneuron -> sensory neuron -> muscle

Accepted Answer

The correct neural path for an automatic response to a stimulus (like feeling a tickle and seeing a spider) involves a sensory neuron detecting the stimulus, an interneuron processing the information in the spinal cord or brain, and a motor neuron carrying the command to the muscles to react, hence A) sensory neuron -> interneuron -> motor neuron -> muscle is the correct sequence.

Question 7

The difference in electrical charge between the inside and the outside of the axon membrane is defined as the _______ potential.
A) membrane
B) local
C) glial
D) action
E) axon

Accepted Answer

The difference in electrical charge between the inside and the outside of the axon membrane is defined as the membrane potential. This potential is crucial for the conduction of nerve impulses along neurons.

Question 8

The function of a _______ in a giant squid physiology experiment is to _______.
A) microelectrode; inject potassium ions into the axon
B) voltmeter; stimulate the interior of the axon
C) microelectrode; compare the electric charge of the interior with that of the exterior
D) voltmeter; compare the electric charge of the interior with that of the exterior
E) microelectrode; dampen the electric charge within the axon

Accepted Answer

The answer of The function of a _______ in a...

Question 9

If the inner voltage of a cell is -70 mV and application of stimulation results in a -95 mV charge, the stimulation had a ____________ effect. On the other hand, a resultant charge of +40 mV would be a ___________ effect.
A) hyperpolarizing; depolarizing
B) depolarizing; hyperpolarizing
C) repolarizing; depolarizing
D) repolarizing; hyperpolarizing
E) hyperpolarizing; repolarizing

Accepted Answer

When the charge becomes more negative (from -70 mV to -95 mV), it is hyperpolarizing which means it is making the cell more negative or further from the threshold required for an action potential. On the other hand, when the charge becomes more positive (from -70 mV to +40 mV), it is depolarizing which means it is making the cell more positive or closer to the threshold required for an action potential.

Question 10

Which of the following is true of the blood-brain barrier?
A) The barrier is uniform, protecting all brain structures.
B) The barrier pumps glucose out of the brain into the bloodstream.
C) The barrier functions to regulate the chemical composition of the extracellular fluid surrounding the brain cells.
D) The barrier is formed by cells that line the capillaries of the brain.
E) The ventricles have a blood-brain barrier.

Accepted Answer

The answer of Which of the following is true of...

Question 11

The _______ is the voltage level at which an action potential is triggered in a patch of axon membrane.
A) resting membrane potential
B) hyperpolarization event
C) threshold of excitation
D) rate level
E) refractory period

Accepted Answer

The threshold of excitation is the voltage level at which an action potential is triggered in a patch of axon membrane. It is the point at which depolarization reaches a certain level and opens enough sodium channels to trigger an action potential. The resting membrane potential is the membrane potential of a neuron when it is at rest, the hyperpolarization event is a change in membrane potential where the inside of the cell becomes more negative than the resting potential, the rate level refers to the firing rate of an action potential, and the refractory period is the time period after an action potential during which the neuron cannot fire another action potential.

Question 12

A substance that forms oppositely charged particles when dissolved into water would be termed a(n)
A) ion.
B) molecule.
C) electrolyte.
D) cation.
E) anion.

Accepted Answer

An electrolyte is a substance that dissolves into ions and is able to conduct electricity when dissolved into water. Therefore, a substance that forms oppositely charged particles when dissolved into water would be considered an electrolyte. Options A, D, and E all refer to specific types of ions, which may or may not be part of an electrolyte. Option B refers to a substance that is made up of two or more atoms bonded together, which may or may not dissolve into ions and be an electrolyte.

Question 13

A cup of sugar is dumped into a gallon of hot water. After 30 minutes, we will expect that the process of _______ will ensure that the sugar molecules are evenly distributed throughout the water.
A) retrograde transport
B) diffusion
C) anterograde transport
D) electrostatic pressure
E) salinity

Accepted Answer

Diffusion is the process by which molecules move from an area of high concentration to an area of low concentration until equilibrium is reached. Thus, in this scenario, the sugar molecules will move from the concentrated area (the cup of sugar) to the less concentrated area (the gallon of water), until they are evenly distributed throughout the water.

Question 14

Activation of cells within the _______ by a poison in the blood would be predicted to produce _______.
A) nucleus accumbens; visual hallucinations
B) hippocampus; locomotion
C) hypothalamus; vomiting
D) area postrema; vomiting
E) hippocampus; vomiting

Accepted Answer

The area postrema is the vomiting center in the brain, and activation of cells within this region by a poison in the blood would be predicted to produce vomiting.

Question 15

Susie takes a huge drink of her coffee, assuming that it is tolerable, and the heat sears her mouth. Although the pain is so great that her reflex is to spit out the coffee, she does not do so. The reflex to spit out the coffee is inhibited at the
A) sensory neuron.
B) interneuron.
C) motor neuron.
D) glial cell.
E) astrocyte.

Accepted Answer

The answer of Susie takes a huge drink of her...

Question 16

The _______ potential is defined as the difference in electrical charge between the inside and the outside of an undisturbed axon membrane.
A) resting membrane
B) local
C) resting
D) action
E) axon

Accepted Answer

The resting membrane potential refers to the electrical charge difference between the interior and exterior regions of an axon membrane while the cell is at rest or not transmitting electrical signals.

Question 17

A change in the axon membrane potential from -70 mV to -90 mV would be termed a(n)
A) depolarization.
B) threshold potential.
C) action potential.
D) hyperpolarization.
E) excitatory local potential.

Accepted Answer

A change in the axon membrane potential from -70 mV (resting potential) to -90 mV (more negative than resting potential) is a hyperpolarization, meaning the membrane potential is further away from the threshold potential needed to initiate an action potential.  Depolarization is a change in membrane potential towards a less negative value, and action potential and threshold potential are specific values (-55 mV for threshold) rather than changes in membrane potential. Excitatory local potential refers to a graded potential in the dendrites or soma that makes an action potential more likely to occur.

Question 18

Which of the following is true of Schwann cells?
A) Schwann cells provide myelin for peripheral nerve cells.
B) Schwann cells are found within the brain.
C) A single Schwann cell wraps multiple segments around a peripheral nerve cell.
D) A single Schwann cell can myelinate up to 50 segments of axon membrane.
E) Schwann cells remove the cellular debris left by dead neurons in brain.

Accepted Answer

Schwann cells provide myelin for peripheral nerve cells. They wrap around a segment of axon, forming a myelin sheath that insulates the axon and increases the speed of nerve impulse conduction. Schwann cells are found in the peripheral nervous system, not the brain. Each Schwann cell wraps around a single segment of axon, not multiple segments. Finally, Schwann cells do not remove cellular debris left by dead neurons in the brain; this is the job of microglia.

Question 19

A key function of the giant squid axon is the
A) integration of sensory messages regarding the environment.
B) planning of feeding-related movements.
C) contraction of the squid mantle, which propels the squid away from danger.
D) coordination of general sensory-motor function.
E) contraction of the oral region to produce chewing movements.

Accepted Answer

The giant squid axon is primarily involved in the rapid conduction of nerve impulses, which are crucial for the contraction of the squid mantle. This contraction propels the squid away from danger, making it a key component in the squid's escape response.

Question 20

A neuron membrane potential moves from -90 mV to -80 mV in response to a brief stimulation. We would term this change in potential as a(n)
A) depolarization.
B) resting potential.
C) action potential.
D) hyperpolarization.
E) inhibitory local potential.

Accepted Answer

This change in potential is termed depolarization because the membrane potential becomes less negative, moving towards zero, which is indicative of depolarization.

Quiz 2: Structure and Function of Cells of the Nervous System

_______ will be recorded from a nerve cell whose membrane potential rises above threshold.

A scan shows that a particular substance has spread throughout the body via the bloodstream but has not entered the brain. This finding demonstrates the existence of

Regrowth of a damaged axon can occur more readily in the peripheral nervous system than in the brain because

The normal order of activation during neuronal transmission is

The interior of a neuron at rest

As you study for your neuroscience exam, you feel a tickle on your arm. You look and see a large spider and you jerk your arm automatically. What might be the neural path for this action?

The difference in electrical charge between the inside and the outside of the axon membrane is defined as the _______ potential.

The function of a _ in a giant squid physiology experiment is to _.

If the inner voltage of a cell is -70 mV and application of stimulation results in a -95 mV charge, the stimulation had a __ effect. On the other hand, a resultant charge of +40 mV would be a _ effect.

Which of the following is true of the blood-brain barrier?

The _______ is the voltage level at which an action potential is triggered in a patch of axon membrane.

A substance that forms oppositely charged particles when dissolved into water would be termed a(n)

A cup of sugar is dumped into a gallon of hot water. After 30 minutes, we will expect that the process of _______ will ensure that the sugar molecules are evenly distributed throughout the water.

Activation of cells within the _ by a poison in the blood would be predicted to produce _.

Susie takes a huge drink of her coffee, assuming that it is tolerable, and the heat sears her mouth. Although the pain is so great that her reflex is to spit out the coffee, she does not do so. The reflex to spit out the coffee is inhibited at the

The _______ potential is defined as the difference in electrical charge between the inside and the outside of an undisturbed axon membrane.

A change in the axon membrane potential from -70 mV to -90 mV would be termed a(n)

Which of the following is true of Schwann cells?

A key function of the giant squid axon is the

A neuron membrane potential moves from -90 mV to -80 mV in response to a brief stimulation. We would term this change in potential as a(n)