Question 1

Use the following to answer questions:
Refer to the graph below, showing the course of an action potential. 
-In the action potential shown, the x-axis should be labeled _______, and the y-axis should be labeled _______.

Accepted Answer

The x-axis shows the elapsed time in milliseconds, while the y-axis shows the voltage in millivolts. These labels are consistent with the conventions used in graphing action potentials.

Question 2

The substance that wraps the axon of many neurons and provides for increased conduction speed is

Accepted Answer

Myelin is the substance that wraps around the axon of many neurons and provides increased conduction speed. It acts as insulation and allows nerve impulses to travel more quickly and efficiently along the axon. Myelin is produced by specialized cells called oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system.

Question 3

In order for neuronal responses to be turned off, synapses must be cleared of _______.

Accepted Answer

The answer of In order for neuronal responses to be...

Question 4

The long extension from the cell body of a neuron that provides the pathway for action potentials to the synapse is the

Accepted Answer

The axon is the long extension of a neuron that transmits action potentials away from the cell body and towards the synapse.

Question 5

Deadly nerve gases inhibit the enzyme _______.

Accepted Answer

The answer of Deadly nerve gases inhibit the enzyme _______....

Question 6

Which of the following statements about neuro­transmitter receptors is false?

Accepted Answer

The acetylcholine receptor at the motor end plate is an ionotropic receptor, not a metabotropic receptor.

Question 7

The refractory period of a neuron

Accepted Answer

The refractory period of a neuron occurs when the inactivated voltage-gated sodium channels are closed, preventing the neuron from firing another action potential. Choice A is incorrect because the sodium-potassium pump continues to function during the refractory period, restoring the resting potential of the neuron. Choice B is incorrect because voltage-gated chlorides channels play no role in the refractory period of a neuron. Choice D is incorrect because the synapse is not directly involved in the refractory period of a neuron, although it may be affected by it. Choice E is incorrect because the refractory period typically lasts only a few milliseconds.

Question 8

The rapid depolarization of a neuron during the first half of an action potential is due to the

Accepted Answer

The rapid depolarization of a neuron during the first half of an action potential is due to the entry of Na+ ions into the cell through gated sodium channels. This influx of positively charged ions changes the membrane potential from negative to positive, causing the depolarization phase of the action potential.

Question 9

The cells that create the blood-brain barrier, keeping some toxic substances from entering the brain, are _______ and belong to a type of neural tissue called _______.

Accepted Answer

Astrocytes are a type of glial cell that contribute to the formation and maintenance of the blood-brain barrier, which protects the brain from harmful substances.

Question 10

Which of the following statements about electrical synapses is false?

Accepted Answer

Electrical synapses are known for their rapid transmission capacity, not slow. They allow direct passage of ions and small molecules between cells, enabling fast communication.

Question 11

Use the following to answer questions:
Refer to the graph below, showing the course of an action potential. 
-In the action potential shown, which of the following cellular events is mispaired with the position at which it occurs?

Accepted Answer

At position 3, voltage-gated potassium channels actually open, not close.

Question 12

Which of the following statements about the process of summation in a neuron is false?

Accepted Answer

The concentration of voltage-gated sodium channels is actually highest at the axon hillock, not in the dendrites of the postsynaptic cell.

Question 13

Refer to the diagram below of a neuromuscular junction. Which cellular event is correctly paired with the location where it occurs?

Accepted Answer

The answer of Refer to the diagram below of a...

Question 14

Glia are specialized to do all of the following except

Accepted Answer

While glia play important roles in supporting and maintaining neurons, they do not receive neural impulses. This is a function reserved for neurons themselves.

Question 15

A particular disease of the nervous system specifically involves the Ca²⁺ channels at the chemical synapses of motor neurons where neurotransmitter is stored and released. In other words, this disease affects the

Accepted Answer

The Ca²⁺ channels specifically play a role in the release of acetylcholine from the axon terminals of motor neurons. Therefore, a disease affecting these channels would likely impact the release of neurotransmitter from the presynaptic cell, and not the postsynaptic cell or ion movement within the postsynaptic cell. Choice A correctly describes this situation.

Question 16

When a membrane is at the resting potential, the concentration of

Accepted Answer

At rest, the cell membrane is polarized with more negative charges inside the cell and more positive charges outside the cell. This is maintained by the sodium-potassium pump, which actively transports 3 sodium ions out of the cell for every 2 potassium ions transported into the cell. This results in the concentration of sodium ions being higher on the outside of the membrane and the concentration of potassium ions being higher on the inside of the membrane. Choice D describes this situation.

Question 17

The electrical events labeled as EPSPs are the result of _______ of the _______ membrane.

Accepted Answer

EPSPs, or Excitatory Postsynaptic Potentials, result in depolarization of the postsynaptic membrane. This occurs when neurotransmitters bind to receptors on the postsynaptic membrane, opening channels that allow positively charged ions to flow into the cell, making it more likely to generate an action potential.

Question 18

Which of the following statements about neurotransmitters is false?

Accepted Answer

Some neurotransmitters like acetylcholine have multiple types of receptors.

Question 19

The threshold of a neuron is the

Accepted Answer

The threshold of a neuron is the membrane voltage at which the membrane potential develops into an action potential, triggering the neuron to fire.

Question 20

The extensions of postsynaptic neurons that provide the main receptive surface for presynaptic neurons are the

Accepted Answer

Dendrites are the extensions of postsynaptic neurons that provide the main receptive surface for presynaptic neurons. They receive signals from other neurons and transmit those signals to the cell body or soma. Nuclei are found in the cell body of neurons and help to regulate gene expression, while axons are the extensions of the neuron that transmit signals away from the cell body. Glia are non-neuronal cells that provide support and protection for neurons. Therefore, the best choice for the extensions of postsynaptic neurons that provide the main receptive surface for presynaptic neurons is dendrites.

Quiz 45: Neurons and Nervous Systems

Use the following to answer questions: Refer to the graph below, showing the course of an action potential. -In the action potential shown, the x-axis should be labeled _, and the y-axis should be labeled _.

The substance that wraps the axon of many neurons and provides for increased conduction speed is

In order for neuronal responses to be turned off, synapses must be cleared of _______.

The long extension from the cell body of a neuron that provides the pathway for action potentials to the synapse is the

Deadly nerve gases inhibit the enzyme _______.

Which of the following statements about neurotransmitter receptors is false?

The refractory period of a neuron

The rapid depolarization of a neuron during the first half of an action potential is due to the

The cells that create the blood-brain barrier, keeping some toxic substances from entering the brain, are _ and belong to a type of neural tissue called _.

Which of the following statements about electrical synapses is false?

Use the following to answer questions: Refer to the graph below, showing the course of an action potential. -In the action potential shown, which of the following cellular events is mispaired with the position at which it occurs?

Which of the following statements about the process of summation in a neuron is false?

Refer to the diagram below of a neuromuscular junction. Which cellular event is correctly paired with the location where it occurs?

Glia are specialized to do all of the following except

A particular disease of the nervous system specifically involves the Ca²⁺ channels at the chemical synapses of motor neurons where neurotransmitter is stored and released. In other words, this disease affects the

When a membrane is at the resting potential, the concentration of

The electrical events labeled as EPSPs are the result of _ of the _ membrane.

Which of the following statements about neurotransmitters is false?

The threshold of a neuron is the

The extensions of postsynaptic neurons that provide the main receptive surface for presynaptic neurons are the

Quiz 45: Neurons and Nervous Systems

Use the following to answer questions: Refer to the graph below, showing the course of an action potential. -In the action potential shown, the x-axis should be labeled _______, and the y-axis should be labeled _______.

The substance that wraps the axon of many neurons and provides for increased conduction speed is

In order for neuronal responses to be turned off, synapses must be cleared of _______.

The long extension from the cell body of a neuron that provides the pathway for action potentials to the synapse is the

Deadly nerve gases inhibit the enzyme _______.

Which of the following statements about neuro­transmitter receptors is false?

The refractory period of a neuron

The rapid depolarization of a neuron during the first half of an action potential is due to the

The cells that create the blood-brain barrier, keeping some toxic substances from entering the brain, are _______ and belong to a type of neural tissue called _______.

Which of the following statements about electrical synapses is false?

Use the following to answer questions: Refer to the graph below, showing the course of an action potential. -In the action potential shown, which of the following cellular events is mispaired with the position at which it occurs?

Which of the following statements about the process of summation in a neuron is false?

Refer to the diagram below of a neuromuscular junction. Which cellular event is correctly paired with the location where it occurs?

Glia are specialized to do all of the following except

A particular disease of the nervous system specifically involves the Ca2+ channels at the chemical synapses of motor neurons where neurotransmitter is stored and released. In other words, this disease affects the

When a membrane is at the resting potential, the concentration of

The electrical events labeled as EPSPs are the result of _______ of the _______ membrane.

Which of the following statements about neurotransmitters is false?

The threshold of a neuron is the

The extensions of postsynaptic neurons that provide the main receptive surface for presynaptic neurons are the

Use the following to answer questions: Refer to the graph below, showing the course of an action potential. -In the action potential shown, the x-axis should be labeled _, and the y-axis should be labeled _.

Which of the following statements about neurotransmitter receptors is false?

The cells that create the blood-brain barrier, keeping some toxic substances from entering the brain, are _ and belong to a type of neural tissue called _.

A particular disease of the nervous system specifically involves the Ca²⁺ channels at the chemical synapses of motor neurons where neurotransmitter is stored and released. In other words, this disease affects the

The electrical events labeled as EPSPs are the result of _ of the _ membrane.