Deck 10: Nervous System I

Question 1

Every neuron has

A)many axons.
B)a cell body.
C)myelin.
D)a neurilemma.

Answer 1

B

Question 2

A myelinated nerve fiber is ______,whereas an unmyelinated nerve fiber is ______.

A)gray,and composing the gray matter of the brain and spinal cord;white,and composing the white matter of the brain and spinal cord
B)white,and composing the gray matter of the brain and spinal cord;gray,and composing the white matter of the brain and spinal cord
C)white,and composing the white matter of the brain and spinal cord;gray,and composing the gray matter of the brain and spinal cord
D)white,and composing the gray matter of the brain and spinal cord;red,and composing the white matter of the brain and spinal cord

Answer 2

C

Question 3

Most of the neurons in the brain and spinal cord are

A)bipolar.
B)unipolar
C)multipolar.
D)nonpolar.

Answer 3

C

Question 4

A neuron may have

A)one axon and many dendrites.
B)one dendrite and many axons.
C)no dendrites.
D)no axons.

Question 5

Myelin is rich in ___________.

A)nucleic acids
B)carbohydrates
C)lipids
D)salts

Question 6

The cytoplasmic extensions that,together with the cell body,provide the main receptive surfaces for neurons are

A)neurofibrils.
B)chromatophilic substance (Nissl bodies).
C)axons.
D)dendrites.

Question 7

Which cells produce myelin in the brain and spinal cord?

A)Schwann cells
B)Astrocytes
C)Microglia
D)Oligodendrocytes

Question 8

Which of the following is unique to neurons?

A)Golgi apparatus
B)Chromatophilic substance
C)Mitochondrion
D)Lysosome

Question 9

The two types of cells of the nervous system are

A)axons and dendrites.
B)neurons and neuroglia.
C)motor neurons and sensory neurons.
D)Schwann cells and microglia.

Question 10

Sensory receptors

A)monitor light
B)monitor sound.
C)detect changes in and outside the body.
D)all of the above.

Question 11

The nervous system

A)detects changes in the internal or external environment.
B)controls the movement of muscles.
C)integrates information from several sources and uses it to determine an appropriate response.
D)all of the above.

Question 12

Myelin

A)is released from a neuron and travels to another neuron.
B)consists of layers of lipids and proteins that wrap around an axon.
C)is produced in response to bacterial infection.
D)is a form of chromatophilic substance that fills Schwann cells.

Question 13

_________ support the axon from within.

A)Dendrites.
B)Nodes of Ranvier.
C)Neurofibrils.
D)Collaterals.

Question 14

Masses of myelinated nerve fibers appear

A)white.
B)gray.
C)brown.
D)transparent.

Question 15

A reason that the axons in the CNS and PNS differ in their ability to regenerate after injury is that

A)axons of the CNS lack myelin.
B)axons of the CNS lack neurilemmae.
C)peripheral nerves lack Schwann cells.
D)peripheral nerves lack endoneurium.

Question 16

The functional connection between two neurons is a

A)dendrite.
B)gap junction.
C)synapse.
D)neurotransmitter.

Question 17

Neurons that conduct impulses from the CNS to muscles or glands are

A)sensory neurons.
B)interneurons.
C)motor neurons.
D)unipolar neurons.

Question 18

Which of the following is(are)a type of neuroglia?

A)Astrocyte
B)Oligodendrocyte
C)Schwann cell
D)All of the above

Question 19

Three general functions of the nervous system are

A)sensory,motor,and predictive.
B)integrative,motor,and sensory.
C)predictive,manipulative,and integrative.
D)reflexive,sensory,and predictive.

Question 20

In order for a severed peripheral nerve to regenerate and recover its original function,nerve fibers must sprout and enter tubes formed by

A)basement membranes and connective tissues.
B)former axons.
C)myelin.
D)nodes of Ranvier.

Question 21

Synaptic knobs are at the ends of

A)axons.
B)dendrites.
C)cell bodies.
D)neuroglia.

Question 22

An excitatory postsynaptic potential lasts for about

A)15 minutes.
B)15 seconds.
C)15 milliseconds.
D)15 microseconds.

Question 23

Dendrites on unipolar neurons are parts of

A)sensory neurons.
B)motor neurons.
C)interneurons.
D)efferent neurons.

Question 24

A nerve cell membrane becomes depolarized as a result of

A)calcium leaving the nerve cell.
B)some ion channels being opened while others are closed.
C)the relative ease with which K⁺ diffuses into the nerve cell.
D)Na⁺ being prevented from passing through the membrane.

Question 25

A stimulus great enough to change the membrane potential and propagate an action potential is said to have reached _________.

A)recruitment
B)threshold
C)summation
D)tetanus

Question 26

When an action potential passes over the surface of a synaptic knob,the contents of the vesicles are released in response to the presence of

A)calcium ions.
B)sodium ions.
C)neurotransmitters.
D)neuropeptides.

Question 27

Action potentials are related to impulses conducted along an axon in that

A)many impulses are required to cause one action potential.
B)active transport of Na⁺ and K⁺ are required for impulse conduction but not for an action potential.
C)impulses are stronger responses than are action potentials.
D)propagation of a series of action potentials along a nerve cell fiber constitutes an impulse.

Question 28

When a nerve fiber is polarized,the concentration of

A)Na⁺ and K⁺ are higher on the inside of the membrane.
B)Na⁺ and K⁺ are higher on the outside of the membrane.
C)Na⁺ is higher on the inside of the membrane and K⁺ is higher on the outside.
D)Na⁺ is higher on the outside of the membrane and K⁺ is higher on the inside.

Question 29

Clusters of neuron cell bodies in the PNS are called _____.

A)neuromas
B)axons
C)ganglia
D)nuclei

Question 30

Transmitting an impulse from one neuron to another involves a(n)

A)impulse stimulating presynaptic dendrites to release a neurotransmitter into a synaptic cleft.
B)impulse stimulating a presynaptic axon to release a neurotransmitter into a synaptic cleft.
C)neurotransmitter traveling from presynaptic dendrites across a synapse to postsynaptic axons or a cell body.
D)neurotransmitter traveling from postsynaptic axons across a synapse to presynaptic dendrites or a cell body.

Question 31

Which of the following ions cross neuron cell membranes most readily?

A)Potassium
B)Sodium
C)Calcium
D)Magnesium

Question 32

If a neuron receives a series of stimuli whose effect is excitatory but subthreshold,the neuron is more excitable to incoming stimulation than before and is said to be

A)graded.
B)amplified.
C)facilitated.
D)refractory.

Question 33

The most rapid conduction of an impulse along an axon occurs on a fiber that is

A)thick and myelinated.
B)thick and unmyelinated.
C)thin and myelinated.
D)thin and unmyelinateD.

Question 34

Which of the following cells is only found in the PNS?

A)Oligodendrocyte
B)Astrocyte
C)Microglial cell
D)Schwann cell

Question 35

Saltatory conduction

A)occurs only if the myelin sheath is continuous.
B)occurs only if nodes of Ranvier are lacking.
C)is faster than conduction on an unmyelinated fiber.
D)is slower than conduction on an unmyelinated fiber.

Question 36

If a resting potential becomes more negative,the membrane is

A)depolarized.
B)hyperpolarized.
C)repolarized.
D)summateD.

Question 37

Which of the following neuroglia are not part of the CNS?

A)Ependymal cells
B)Astrocytes
C)Satellite cells
D)Microglia

Question 38

Presynaptic neurons release neurotransmitters by ______________.

A)endocytosis.
B)exocytosis.
C)diffusion.
D)active transport.

Question 39

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

Question 40

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

A)Beta endorphin
B)Acetylcholine
C)Epinephrine
D)Dopamine

Question 41

The neurotransmitter that controls skeletal muscle contraction is

A)beta endorphin.
B)nitric oxide.
C)acetylcholine.
D)GABA.

Question 42

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.

Question 43

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)amyotrophic lateral sclerosis.

Question 44

An action potential is triggered if

A)EPSPs overpower IPSPs.
B)IPSPs overpower EPSPs.
C)chloride channels open.
D)the membrane hyperpolarizes.

Question 45

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

Question 46

A drug that functions as an agonist

A)activates a receptor,helping a neurotransmitter bind or triggering an action potential in some other way.
B)causes great pain if taken in too high a dose.
C)blocks a receptor so that the neurotransmitter cannot bind.
D)relieves pain.

Question 47

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.

Question 48

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.

Question 49

Opiate drugs derived from poppies relieve pain in humans because the human nervous system has

A)neurotransmitters.
B)receptors for endogenous opiates.
C)myelin.
D)sodium and potassium membrane channels.

Question 50

The neurotransmitter most likely produced when a person uses a drug that creates a sense of well-being is

A)glutamic acid.
B)dopamine.
C)enkephalin.
D)substance Q.

Question 51

A nerve is a single neuron that transmits impulses.

Question 52

Marjorie takes an anti-anxiety drug so that she can sleep better and remain calm enough to study effectively.She begins by taking 25 milligrams every evening,but within a month,this dose is no longer helping,so she takes two pills.After another month,this dosage is no longer effective.This is happening because

A)her immune system is rejecting the drug.
B)she has developed tolerance,which means that her liver can no longer metabolize the drug,so it remains active for too long.
C)the number of receptors to which the drug binds on neurons has declined.
D)the number of receptors to which the drug binds on neurons has increaseD.

Question 53

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 or into nearby neuroglia or neurons.
D)an enzyme breaks down a neurotransmitter and then another enzyme builds it back up.

Question 54

Drugs that decrease membrane permeability to sodium

A)are used as local anesthetics.
B)prevent nerve impulses from passing through the affected body part.
C)lessen pain.
D)all of the above.

Question 55

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.

Question 56

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.

Question 57

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.

Question 58

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.

Question 59

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.

Question 60

The types of neurons that are organized into neuronal pools are

A)interneurons.
B)intraneurons.
C)Schwann cells.
D)astrocytes.

Question 61

Neuroglia are specialized to react to environmental change,and neurons support neuroglia.

Question 62

Nodes of Ranvier lie between neurons.

Question 63

Myelin is composed largely of carbohydrates.

Question 64

During the absolute refractory period,a stimulus of high intensity may trigger a nerve impulse.

Question 65

Muscles and glands that respond to nervous stimulation are called _______.

Question 66

A(n)______ is the junction between neurons.

Question 67

A mixed nerve includes different neuroglial cells.

Question 68

Because the response of a nerve fiber is all-or-none,a greater intensity of stimulus does not produce a stronger impulse.

Question 69

The space between neurons is called the neuronal space.

Question 70

Axon branches are called collaterals.

Question 71

Astrocytes structurally support neurons and also provide important signals and nutrients to neurons.

Question 72

Interneurons are specialized to carry impulses from receptor cells into the brain or spinal cord.

Question 73

In convergence,two or more incoming fibers contact a single neuron,whereas in divergence,impulses leaving a neuron pass into several output fibers.

Question 74

The cells in the nervous system that fill spaces and support neurons both physically and nutritionally are called ______.

Question 75

Sensory receptors are part of the CNS.

Question 76

Sheaths of ______ cells often enclose the larger axons outside of the brain and spinal cord.

Question 77

Several nerve fibers converging onto one neuron amplifies impulses.

Question 78

The somatic nervous system controls voluntary actions and the autonomic nervous system oversees involuntary actions.

Question 79

Enkephalins are neuropeptides.

Question 80

The brain and spinal cord comprise the central nervous system.