Question 1

The arrival of a(n)____ causes synaptic vesicles to be released from their protein anchors, allowing the vesicles to fuse with the cell membrane and release ____ into the synaptic cleft.

Accepted Answer

The arrival of an action potential (electrical charge) causes synaptic vesicles to be released from their protein anchors, allowing the vesicles to fuse with the cell membrane and release neurotransmitters into the synaptic cleft. Therefore, option A is the correct choice. Option B is incorrect because the neurotransmitter itself is not capable of producing an electrical charge. Option C is partially incorrect because while the arrival of an action potential does produce an electrical charge, it does not release an electrical charge into the synaptic cleft. Option D is incorrect because releasing more neurotransmitters would require additional action potentials, which is not discussed in the sentence.

Question 2

Myelin, which insulates many neuronal axons, is formed by ____.

Accepted Answer

Myelin is formed by glial membranes, specifically either oligodendrocytes in the central nervous system or Schwann cells in the peripheral nervous system.

Question 3

Synaptic communication between two neurons usually occurs via ____.

Accepted Answer

Synaptic communication between two neurons usually occurs via chemical messengers, also known as neurotransmitters. These neurotransmitters are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, causing an electrical and chemical signal to propagate through the neurons. Direct contact and electrical signaling are not typical modes of synaptic communication, and while molecular transduction can play a role in some types of cellular signaling, it is not the primary mechanism for synaptic communication between neurons.

Question 4

A squid axon is large enough to be visible to the naked eye, while a human axon can only be viewed with a microscopic. Compared with an action potential for a human axon, the size of an action potential for a squid axon will be ____.

Accepted Answer

The answer of A squid axon is large enough to...

Question 5

Juan, a graduate student in an electrophysiology lab, stimulates an isolated neuron grown in a petri dish and measures its action potential. How will the neuron respond to the firing of the action potential?

Accepted Answer

The answer of Juan, a graduate student in an electrophysiology...

Question 6

Professor Freeman calls on his student Maya to describe how the presence of myelin affects an action potential. Maya should respond with which of the following statements?

Accepted Answer

The answer of Professor Freeman calls on his student Maya...

Question 7

Chemical messengers used in neuronal communication are referred to as ____.

Accepted Answer

Chemical messengers used in neuronal communication are specifically called neurotransmitters. The other answer choices are similar terms, but not as precise for this definition.

Question 8

Neuronal communication is a two-step process. In the second step, which takes place between two neurons, what does the arrival of an action potential at the axon terminal of the first neuron signal?

Accepted Answer

The arrival of an action potential at the axon terminal of the first neuron signals the release of neurotransmitters into the extracellular fluid. This release allows the neurotransmitters to cross the synapse and bind to receptors on the second neuron, initiating a response in that neuron.

Question 9

Following a spinal cord injury, formation of the ____ prevents neuronal regeneration in the ____.

Accepted Answer

After a spinal cord injury, scar tissue formed by glial cells prevents neuronal regeneration in the central nervous system (CNS). The blood-brain barrier is a specialized structure that regulates the exchange of substances between the blood and the brain, but it is not directly related to the inhibition of neuronal regeneration after a spinal cord injury. The peripheral nervous system (PNS) does not have scar tissue-forming glial cells like the CNS, so this option is also incorrect.

Question 10

Marcus, who works in the laboratory of Dr. Flores, a prominent electrophysiologist, takes readings with a recording electrode placed within a squid axon. He reports to Dr. Flores that the cell is firing an action potential. What measurement did Marcus take with the recording electrode?

Accepted Answer

The measurement that Marcus took with the recording electrode is the voltage of the squid axon during an action potential. The normal resting potential of a squid axon is around -70 mV, but during an action potential, the voltage increases rapidly, typically reaching around +40 mV before returning to the resting potential. Therefore, choice C (+40 mV) is the correct answer.

Question 11

Marcus works in the laboratory of Dr. Flores, an expert in the electrophysiology of squid axons. After taking a reading from a recording electrode placed within a squid axon, Marcus comments to Dr. Flores that the squid axon is at its resting potential. What measurement did Marcus take with the recording electrode?

Accepted Answer

The resting potential of squid axons is typically around -70 mV. Therefore, if Marcus commented that the squid axon was at its resting potential, it is likely that he measured a membrane potential of -70 mV with the recording electrode.

Question 12

Marcus is excited to be working in the laboratory of Dr. Flores, an expert on electrical signaling in neurons. However, he is surprised to learn that the research is done on squid axons placed in sea water. He asks Dr. Flores the reasons for this. Which of the following is NOT one of the reasons that Dr. Flores provides?

Accepted Answer

Squid axons are not myelinated, therefore option C is not a valid reason why Dr. Flores would use them in her research. All of the other options are valid reasons which Dr. Flores may give for using squid axons in her research.

Question 13

Marcus is conducting a squid axon electrophysiology experiment with Dr. Flores. While monitoring a recording electrode placed within a squid axon, Marcus reports to Dr. Flores that the neuron is in a refractory period. What does this mean?

Accepted Answer

During the refractory period, the cell is hyperpolarized and cannot fire another action potential. This is due to the fact that the sodium channels responsible for depolarization have not yet reset, making it difficult for the cell to reach the threshold for another action potential. Therefore, choice A is the best answer.

Question 14

Elaine, a graduate student in a neuroscience department, is interested in understanding the effects of popular herbal remedies on neuronal communication. After growing neurons in a petri dish, she exposes the neurons to several common herbal supplements. After performing a series of electrophysiology experiments, she notes that one class of herbal supplements caused the neurons to become depolarized. What does this mean?

Accepted Answer

Depolarization means that the difference in electrical charges between the extracellular and intracellular recordings has decreased. This decrease in the charge difference makes it easier for an action potential to occur, increasing the chances of neuronal communication. Therefore, choice A is the correct answer.

Question 15

Which is an accurate statement regarding the generation of an action potential?

Accepted Answer

When a neuron becomes depolarized to the threshold level, an action potential is inevitable. This is because the depolarization triggers the opening of voltage-gated ion channels in the axon membrane, causing a rapid influx of sodium ions and subsequent depolarization of the cell. This depolarization then triggers the opening of potassium channels, causing an efflux of potassium ions and repolarization of the cell. The resulting action potential is a brief, all-or-nothing event that propagates down the axon. Hyperpolarization, on the other hand, makes it more difficult for the cell to reach threshold and generate an action potential.

Question 16

Denise, a first year graduate student, is getting ready to begin a lab rotation with Dr. Hudson, an expert on the nodes of Ranvier. What should Denise know about the nodes of Ranvier before beginning her lab rotation?

Accepted Answer

The answer of Denise, a first year graduate student, is...

Question 17

Synaptic vesicles have been released from their protein anchors. What happens next?

Accepted Answer

The answer of Synaptic vesicles have been released from their...

Question 18

Georgio is jogging barefoot along the beach when he suddenly steps on the sharp edge of a broken shell. He instantly feels pain due to the message carried to his brain by ____. He then slowly walks home with an achy foot. The message of the ache is carried by ____.

Accepted Answer

The answer of Georgio is jogging barefoot along the beach...

Question 19

How does myelination affect the signal transmission of a neuron?

Accepted Answer

Myelination speeds up the transmission of a signal along the axon of a neuron by allowing the signal to jump quickly from one node of Ranvier to the next.

Question 20

Once the "threshold" for an action potential is reached what is the sequence of events that occur? 1. Potassium channels are activated and potassium ions move out of the neuron. 2. Sodium channels are activated and sodium ions move into the neuron. 3. The interior of the neuron becomes more negatively charged than the exterior. 4. The interior of the neuron becomes more positively charged than the exterior.

Accepted Answer

Once the threshold for an action potential is reached, sodium channels are activated and sodium ions move into the neuron, causing the interior of the neuron to become more positively charged than the exterior (step 2 and 4). This depolarization also activates potassium channels, which allow potassium ions to move out of the neuron, helping to restore the negative charge inside the neuron (step 1). After the action potential peaks, the potassium channels remain open, causing an efflux of potassium ions that helps to bring the neuron's membrane potential back to its resting state (step 3). Therefore, the correct sequence of events is 2, 4, 1, 3.

Quiz 4: The Biological Mind: the Physical Basis of Behavior

The arrival of a(n) causes synaptic vesicles to be released from their protein anchors, allowing the vesicles to fuse with the cell membrane and release into the synaptic cleft.

Myelin, which insulates many neuronal axons, is formed by ____.

Synaptic communication between two neurons usually occurs via ____.

A squid axon is large enough to be visible to the naked eye, while a human axon can only be viewed with a microscopic. Compared with an action potential for a human axon, the size of an action potential for a squid axon will be ____.

Juan, a graduate student in an electrophysiology lab, stimulates an isolated neuron grown in a petri dish and measures its action potential. How will the neuron respond to the firing of the action potential?

Professor Freeman calls on his student Maya to describe how the presence of myelin affects an action potential. Maya should respond with which of the following statements?

Chemical messengers used in neuronal communication are referred to as ____.

Neuronal communication is a two-step process. In the second step, which takes place between two neurons, what does the arrival of an action potential at the axon terminal of the first neuron signal?

Following a spinal cord injury, formation of the prevents neuronal regeneration in the .

Marcus, who works in the laboratory of Dr. Flores, a prominent electrophysiologist, takes readings with a recording electrode placed within a squid axon. He reports to Dr. Flores that the cell is firing an action potential. What measurement did Marcus take with the recording electrode?

Marcus is conducting a squid axon electrophysiology experiment with Dr. Flores. While monitoring a recording electrode placed within a squid axon, Marcus reports to Dr. Flores that the neuron is in a refractory period. What does this mean?

Which is an accurate statement regarding the generation of an action potential?

Denise, a first year graduate student, is getting ready to begin a lab rotation with Dr. Hudson, an expert on the nodes of Ranvier. What should Denise know about the nodes of Ranvier before beginning her lab rotation?

Synaptic vesicles have been released from their protein anchors. What happens next?

Georgio is jogging barefoot along the beach when he suddenly steps on the sharp edge of a broken shell. He instantly feels pain due to the message carried to his brain by . He then slowly walks home with an achy foot. The message of the ache is carried by .

How does myelination affect the signal transmission of a neuron?

Quiz 4: The Biological Mind: the Physical Basis of Behavior

The arrival of a(n) ____ causes synaptic vesicles to be released from their protein anchors, allowing the vesicles to fuse with the cell membrane and release ____ into the synaptic cleft.

Myelin, which insulates many neuronal axons, is formed by ____.

Synaptic communication between two neurons usually occurs via ____.

A squid axon is large enough to be visible to the naked eye, while a human axon can only be viewed with a microscopic. Compared with an action potential for a human axon, the size of an action potential for a squid axon will be ____.

Juan, a graduate student in an electrophysiology lab, stimulates an isolated neuron grown in a petri dish and measures its action potential. How will the neuron respond to the firing of the action potential?

Professor Freeman calls on his student Maya to describe how the presence of myelin affects an action potential. Maya should respond with which of the following statements?

Chemical messengers used in neuronal communication are referred to as ____.

Neuronal communication is a two-step process. In the second step, which takes place between two neurons, what does the arrival of an action potential at the axon terminal of the first neuron signal?

Following a spinal cord injury, formation of the ____ prevents neuronal regeneration in the ____.

Marcus, who works in the laboratory of Dr. Flores, a prominent electrophysiologist, takes readings with a recording electrode placed within a squid axon. He reports to Dr. Flores that the cell is firing an action potential. What measurement did Marcus take with the recording electrode?

Marcus is conducting a squid axon electrophysiology experiment with Dr. Flores. While monitoring a recording electrode placed within a squid axon, Marcus reports to Dr. Flores that the neuron is in a refractory period. What does this mean?

Which is an accurate statement regarding the generation of an action potential?

Denise, a first year graduate student, is getting ready to begin a lab rotation with Dr. Hudson, an expert on the nodes of Ranvier. What should Denise know about the nodes of Ranvier before beginning her lab rotation?

Synaptic vesicles have been released from their protein anchors. What happens next?

Georgio is jogging barefoot along the beach when he suddenly steps on the sharp edge of a broken shell. He instantly feels pain due to the message carried to his brain by ____. He then slowly walks home with an achy foot. The message of the ache is carried by ____.

How does myelination affect the signal transmission of a neuron?

The arrival of a(n) causes synaptic vesicles to be released from their protein anchors, allowing the vesicles to fuse with the cell membrane and release into the synaptic cleft.

Following a spinal cord injury, formation of the prevents neuronal regeneration in the .

Georgio is jogging barefoot along the beach when he suddenly steps on the sharp edge of a broken shell. He instantly feels pain due to the message carried to his brain by . He then slowly walks home with an achy foot. The message of the ache is carried by .