Question 1

In reuptake
A)an action potential reverses direction.
B)a neuropeptide breaks down into amino acids, which act as neurotransmitters.
C)a neurotransmitter that has already been released into the synaptic cleft is taken back into the synaptic knob of the presynaptic neuron.
D)an enzyme breaks down a neurotransmitter and then another enzyme builds it back up.

Accepted Answer

In reuptake, a neurotransmitter that has already been released into the synaptic cleft is taken back into the synaptic knob of the presynaptic neuron. This helps to regulate the levels of neurotransmitters in the synaptic cleft and ensure proper neuronal communication.

Question 2

A neuron in the aorta detects oxygen content in the blood and relays this information to the brain. This neuron is a ________ of the ________ pathway.
A)effector; afferent
B)effector; efferent
C)sensory receptor; afferent
D)sensory receptor; efferent

Accepted Answer

The neuron in the aorta is a sensory receptor, as it detects oxygen content in the blood, and it relays this information to the brain through afferent pathways. Therefore, the correct choice is C, which indicates that the neuron is a sensory receptor of the afferent pathway.

Question 3

An immune response that affects the myelin coating on axons throughout the spinal cord and brain, triggering inflammation and leaving scars, is
A)muscular dystrophy.
B)multiple sclerosis.
C)Alzheimer disease.
D)cerebrovascular accident.

Accepted Answer

The immune response that affects the myelin coating on axons throughout the spinal cord and brain, triggering inflammation and leaving scars, is characteristic of multiple sclerosis. Muscular dystrophy is a genetic disorder that primarily affects the muscles, Alzheimer's disease is a degenerative disorder that primarily affects cognitive function, and a cerebrovascular accident (commonly known as a stroke) involves disruption of blood flow to the brain.

Question 4

Neurotransmitters that are modified amino acids are
A)dopamine, serotonin, epinephrine, and norepinephrine.
B)enkephalins, endorphins, and substance P.
C)aspartic acid, glutamic acid, glycine, and GABA.
D)potassium, sodium, and calcium ions.

Accepted Answer

Dopamine, serotonin, epinephrine, and norepinephrine are all modified amino acids that act as neurotransmitters.

Question 5

Each neuron in the CNS may receive input from
A)only one synaptic knob.
B)one synaptic knob at each end.
C)about 10 dendrites.
D)thousands of axons.

Accepted Answer

Neurons in the central nervous system (CNS) can receive input from thousands of axons. Each of these axons can form a synapse with the neuron, allowing for complex processing and integration of information.

Question 6

What is the correct sequence of events along an axon that follows a membrane reaching threshold potential? 1. The membrane depolarizes.
2) Sodium channels open and sodium ions diffuse inward.
3) The membrane repolarizes.
4) Potassium channels open and potassium ions diffuse outward.
A)3, 2, 4, 1
B)2, 1, 4, 3
C)1, 2, 4, 3
D)4, 1, 3, 2

Accepted Answer

The answer of What is the correct sequence of events...

Question 7

Viagra is a drug used to treat erectile dysfunction by dilating arteries in the penis. The neurotransmitter that Viagra affects is
A)acetylcholine.
B)nitric oxide.
C)serotonin.
D)histamine.

Accepted Answer

Viagra acts by inhibiting the enzyme phosphodiesterase type 5 (PDE5), which breaks down cyclic guanosine monophosphate (cGMP) in the penis. cGMP is responsible for relaxing smooth muscle cells in blood vessels, allowing vasodilation (dilation of blood vessels) and increased blood flow to the penis, resulting in an erection. Nitric oxide (NO) is a crucial signaling molecule that stimulates the production of cGMP, and Viagra enhances its activity by preventing its breakdown by PDE5.

Question 8

Migraine results from
A)release of calcitonin gene-related peptide from the trigeminal nerves at the base of the brain, in response to a spreading wave of excitation followed by lack of response from the cortex.
B)not eating enough chocolate, which causes a spreading effect in the cortex.
C)a neurotransmitter deficiency.
D)release of an abnormal form of beta endorphin from the trigeminal nerves at the base of the brain, in response to cortical stimulation.

Accepted Answer

Migraine is believed to result from the release of calcitonin gene-related peptide (CGRP) from the trigeminal nerves at the base of the brain. This occurs in response to a spreading wave of excitation, followed by lack of response from the cortex. This theory is supported by the efficacy of CGRP antagonists in migraine treatment. The other options (B, C, and D) are not supported by current scientific understanding of migraine.

Question 9

The types of neurons that are organized into neuronal pools are
A)interneurons.
B)intraneurons.
C)Schwann cells.
D)astrocytes.

Accepted Answer

Only interneurons are typically organized into neuronal pools, which are groups of interconnected neurons that work together to carry out a particular function or behavior. Intraneurons, Schwann cells, and astrocytes are not organized in this way.

Question 10

Which of the following molecules is responsible for "runner's high," a good feeling that accompanies long-distance running?
A)Endorphin
B)Acetylcholine
C)Epinephrine
D)Dopamine

Accepted Answer

Endorphins are responsible for the "runner's high" that is experienced during long-distance running. These molecules are released in response to prolonged exercise and are known for their ability to produce feelings of euphoria and pain relief. While other molecules, such as dopamine and epinephrine, may play a role in exercise-induced feelings of well-being, the release of endorphins is considered to be the primary cause of the "runner's high."

Question 11

Drugs that inhibit the enzyme monoamine oxidase
A)allow increased activity of norepinephrine.
B)decompose norepinephrine.
C)decrease the activity of serotonin.
D)decompose serotonin.

Accepted Answer

Inhibiting the enzyme monoamine oxidase prevents the breakdown of norepinephrine (as well as other monoamines such as dopamine and serotonin), allowing it to accumulate and be more active in the body.

Question 12

The neurotransmitter that controls skeletal muscle contraction is
A)beta endorphin.
B)nitric oxide.
C)acetylcholine.
D)GABA.

Accepted Answer

Acetylcholine is the neurotransmitter that is responsible for controlling skeletal muscle contraction. When acetylcholine is released from motor neurons, it binds to receptors on muscle fibers, causing them to contract.

Question 13

Convergence refers to
A)dendrites from neurons in different parts of the nervous system contacting the same neuron.
B)axons from neurons in different parts of the nervous system contacting the same neuron.
C)dendrites from the same neuron touching each other.
D)a neuroglial cell that contacts many neurons.

Accepted Answer

Convergence is the process by which axons from neurons located in different parts of the nervous system come into contact with the same neuron. This phenomenon is important for integrating information from multiple sources and allowing for complex neural processing.

Question 14

An action potential is triggered if
A)EPSPs overpower IPSPs.
B)IPSPs overpower EPSPs.
C)chloride channels open.
D)the membrane hyperpolarizes.

Accepted Answer

An action potential is triggered when excitatory postsynaptic potentials (EPSPs) overpower inhibitory postsynaptic potentials (IPSPs), leading to the depolarization of the neuron's membrane above a certain threshold.

Question 15

Neural stem cells can be harvested from autopsies and stored, alive, in banks, whereas neurons cannot, because
A)people do not will them to science.
B)neural stem cells have lower oxygen and energy requirements than neurons.
C)neural stem cells have higher oxygen and energy requirements than neurons.
D)neural stem cells have more globular shapes than neurons.

Accepted Answer

Neural stem cells have lower oxygen and energy requirements than neurons, which means they can survive longer outside the body and be stored in banks for future research or medical use. Neurons, on the other hand, require a constant supply of oxygen and nutrients to function and cannot survive outside the body.

Question 16

Diverging axons amplify an impulse by
A)contacting many neurons.
B)returning the impulse to the neuron of origin.
C)splitting into multiple axons.
D)stimulating themselves.

Accepted Answer

Diverging axons contact many neurons, which allows for the impulse to be spread and amplified.

Question 17

If a resting potential becomes more negative, the membrane is
A)depolarized.
B)hyperpolarized.
C)repolarized.
D)summated.

Accepted Answer

If a resting potential becomes more negative, this means that the cell membrane has become more polarized, or hyperpolarized. This occurs when there is an influx of negatively charged ions, such as chlorine ions, into the cell or an efflux of positively charged ions, such as potassium ions, out of the cell. This increased polarization makes it more difficult for the cell to reach the threshold potential required for an action potential to be generated.

Question 18

A nerve cell membrane becomes depolarized as a result of
A)Ca⁺² leaving the nerve cell.
B)Na⁺ ion channels being opened and Na⁺ ions diffusing into the cell.
C)the relative ease with which K⁺ diffuses into the nerve cell.
D)Na⁺ being prevented from passing through the membrane.

Accepted Answer

When Na⁺ ion channels open, Na⁺ ions diffuse into the cell, causing the membrane to become depolarized.

Question 19

An excitatory postsynaptic potential lasts for about
A)15 minutes.
B)15 seconds.
C)15 milliseconds.
D)15 microseconds.

Accepted Answer

An excitatory postsynaptic potential (EPSP) typically lasts for about 15 milliseconds. This is because EPSPs are caused by the brief influx of positively charged ions into the postsynaptic neuron, which activates various cellular processes that ultimately lead to an action potential. The duration of an EPSP is determined by the properties of the receptors and channels involved in neurotransmitter release and signaling, as well as the overall membrane properties of the postsynaptic neuron. While EPSPs can vary in amplitude and duration depending on these factors, 15 milliseconds is a commonly cited estimate for their typical duration.

Question 20

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are most likely used to treat
A)multiple sclerosis.
B)Tay-Sachs disease.
C)clinical depression.
D)erectile dysfunction.

Accepted Answer

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are referred to as antidepressants, and they are commonly used to treat clinical depression. Multiple sclerosis and Tay-Sachs disease are not typically treated with these drugs, and while some drugs that affect norepinephrine and serotonin may be used to treat erectile dysfunction, they are not typically used for this purpose.

Quiz 10: Nervous System I: Basic Structure and Function

In reuptake

A neuron in the aorta detects oxygen content in the blood and relays this information to the brain. This neuron is a of the pathway.

An immune response that affects the myelin coating on axons throughout the spinal cord and brain, triggering inflammation and leaving scars, is

Neurotransmitters that are modified amino acids are

Each neuron in the CNS may receive input from

What is the correct sequence of events along an axon that follows a membrane reaching threshold potential? 1. The membrane depolarizes. 2) Sodium channels open and sodium ions diffuse inward. 3) The membrane repolarizes. 4) Potassium channels open and potassium ions diffuse outward.

Viagra is a drug used to treat erectile dysfunction by dilating arteries in the penis. The neurotransmitter that Viagra affects is

Migraine results from

The types of neurons that are organized into neuronal pools are

Which of the following molecules is responsible for "runner's high," a good feeling that accompanies long-distance running?

Drugs that inhibit the enzyme monoamine oxidase

The neurotransmitter that controls skeletal muscle contraction is

Convergence refers to

An action potential is triggered if

Neural stem cells can be harvested from autopsies and stored, alive, in banks, whereas neurons cannot, because

Diverging axons amplify an impulse by

If a resting potential becomes more negative, the membrane is

A nerve cell membrane becomes depolarized as a result of

An excitatory postsynaptic potential lasts for about

Drugs that increase the actions of norepinephrine and/or serotonin by keeping them in synapses longer are most likely used to treat