Question 1

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 2

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 term described in the question is the resting membrane potential, which is the baseline electrical charge difference across the axon membrane when it is not being stimulated. The other choices, local potential, action potential, and axon potential, all describe different types of changes in the membrane potential that occur when the neuron is being stimulated or sending a signal, and are therefore not the best answer for this question.

Question 3

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 particles move from areas of high concentration to areas of low concentration. When sugar is dumped into water, the sugar molecules will move from areas of high concentration (where the sugar was dumped) to areas of low concentration (the rest of the water) until they are evenly distributed throughout the water. This process can be aided by stirring the mixture to help speed up the diffusion of the sugar molecules.

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

_______ 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 is a brief electrical signal that is recorded from a nerve cell after its membrane potential rises above threshold.

Question 6

The process by which similarly charged particles repel each other and are thus moved within a medium is termed
A) diffusion.
B) carrier-mediated transport.
C) refraction.
D) electrostatic pressure.
E) diffraction.

Accepted Answer

The process described in the question is electrostatic pressure, as similarly charged particles repel each other due to their charges. Diffusion involves movement from high concentration to low concentration, carrier-mediated transport involves a protein carrier facilitating movement across a membrane, refraction involves the bending of light through a medium, and diffraction involves the bending of waves around an object.

Question 7

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 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

The simplest version of a withdrawal from pain reflex is a
A) pain receptor that synapses onto an interneuron, which in turn activates a motor neuron in the spinal cord.
B) pain receptor that projects to the thalamus, which then projects to motor cortex and then back down to the spinal cord.
C) motor neuron within the spinal cord that is spontaneously active.
D) sensory neuron in the visual cortex that synapses onto a motor neuron in the spinal cord.
E) motor neuron that activates sensory fibers.

Accepted Answer

The simplest version of a withdrawal from pain reflex involves a pain receptor that synapses onto an interneuron in the spinal cord, which in turn activates a motor neuron. This causes the muscles to contract and move the affected body part away from the painful stimulus. This reflex pathway is known as the spinal reflex arc and does not require input from the brain. Therefore, choice A is the best answer.

Question 10

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 to -90 mV signifies a decrease in the membrane potential, which is called hyperpolarization. Depolarization is a change in the axon membrane potential towards zero, whereas threshold potential is the minimum membrane potential required to initiate an action potential. Action potential is a brief reversal in the membrane potential that allows for the transmission of nerve impulses. Excitatory local potential causes depolarization of the axon membrane potential.

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 a critical level of depolarization that must be reached in order for an action potential to be produced.

Question 12

_______ are negatively charged particles.
A) Transmitters
B) Solvents
C) Electrolytes
D) Cations
E) Anions

Accepted Answer

Anions are negatively charged particles, while cations are positively charged particles. Transmitters are chemicals that transmit signals between nerve cells. Solvents are substances that dissolve other substances. Electrolytes are substances that conduct electricity when dissolved in water.

Question 13

The presence of a barrier between the bloodstream and the brain is suggested by the observation that
A) all cells of the body are stained by a dye injected into the bloodstream.
B) injection of dye into the bloodstream stains all cells but those of the brain and spinal cord.
C) the gut is stained by a dye injected into the brain ventricles.
D) injection of dye into the spinal cord stains the cells of the gut.
E) injection of dye into the gut stains the cells of the spinal cord.

Accepted Answer

The fact that injection of dye into the bloodstream stains all cells except those of the brain and spinal cord suggests that there is a barrier preventing the dye from entering the brain and spinal cord. This barrier is known as the blood-brain barrier. Option A is incorrect as it contradicts the observation. Option C, D and E are also incorrect as they do not provide evidence for the presence of a blood-brain barrier.

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, located in the medulla oblongata, is particularly sensitive to toxins and triggers vomiting in response to toxic substances in the blood. Activation of cells in the other brain regions listed (nucleus accumbens, hippocampus, hypothalamus) would not necessarily produce vomiting as a response.

Question 15

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 due to the unequal distribution of ions across the cell membrane, with more negatively charged ions inside and more positively charged ions outside. This creates a voltage potential across the membrane known as the resting potential. Option A is incorrect because the concentrations of sodium and potassium are much higher outside and inside the cell, respectively. Option B is incorrect because the resting potential is a negative voltage potential inside the cell. Option E is also incorrect because the potassium concentration is higher inside the cell.

Question 16

A neuron membrane potential moves from -90 mV to -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

Moving from -90 mV to a less negative value indicates a depolarization, meaning the membrane potential is becoming more positive. Resting potential refers to the stable, negative potential of a neuron when it is not actively firing. Action potential refers to the brief, all-or-nothing depolarization of a neuron that allows it to transmit signals. Hyperpolarization occurs when the membrane potential becomes more negative than its resting potential, while inhibitory local potentials refer to small, temporary hyperpolarizations caused by inhibitory signals.

Question 17

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 18

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

A substance that forms oppositely charged particles when dissolved into water is referred to as an electrolyte. Electrolytes are compounds that can conduct electricity when they are dissolved in water or melted. They form positively charged ions (cations) and negatively charged ions (anions) when they dissolve, resulting in an electrically conductive solution.

Question 19

_______ are positively charged ionic particles.
A) Transmitters
B) Solvents
C) Electrolytes
D) Cations
E) Anions

Accepted Answer

Cations are positively charged ions that have lost one or more electrons.

Question 20

_______ are charged particles formed when an electrolyte dissolves in water.
A) Ions
B) Solvents
C) Transmitters
D) Electrons
E) Solutes

Accepted Answer

Charged particles formed when an electrolyte dissolves in water are known as ions.

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

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

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

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.

The normal order of activation during neuronal transmission is

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

The process by which similarly charged particles repel each other and are thus moved within a medium is termed

A key function of the giant squid axon is the

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

The simplest version of a withdrawal from pain reflex is a

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

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

_______ are negatively charged particles.

The presence of a barrier between the bloodstream and the brain is suggested by the observation that

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

The interior of a neuron at rest

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

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

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

_______ are positively charged ionic particles.

_______ are charged particles formed when an electrolyte dissolves in water.