Deck 2: Structure and Function of the Nervous System

Question 1

The term saltatory conduction refers to the fact that

A)action potentials travel faster when extracellular salt concentration is high.
B)action potentials evoked by strong stimuli travel faster than those evoked by weaker stimuli.
C)action potentials appear to jump from node to node in myelinated axons.
D)action potentials are generated only by myelinated portions of axons.

Answer 1

C

Question 2

If you were to insert a microelectrode through the cell membrane of a neuron, you would be able to demonstrate that

A)the region inside the cell membrane is more positively charged than the region outside the membrane.
B)the region inside the cell membrane is more negatively charged than the region outside the membrane.
C)there is a greater concentration of potassium ions outside the cell membrane than inside the membrane.
D)there is a greater concentration of potassium ions inside the cell membrane than outside the membrane.

Answer 2

B

Question 3

Within a neuron, the transmission of information is usually ________. Between neurons, the transmission of information is usually ________.

A)chemical; chemical
B)electrical; electrical
C)electrical; chemical
D)chemical; electrical

Answer 3

C

Question 4

In the nervous system, these cells provide structural support and insulation for neurons.

A)glia
B)dendrites
C)mitochondria
D)Purkinje cells

Question 5

___________ enable(s) the rapid transmission of action potentials down an axon and increase(s) the distance over which transmission can occur.

A)Soma
B)Dendrites
C)Neurotransmitters
D)Myelin

Question 6

The primary reason why neurons are refractory for a short period after firing action potentials, and the reason underlying the absolute refractory period, is that the

A)voltage-gated sodium channels are inactivated.
B)voltage-gated potassium channels are inactivated.
C)sodium-potassium pump has to remove sodium ions from inside the cell.
D)sodium-potassium pump has to retrieve potassium ions from outside the cell.

Question 7

Demyelinating diseases such as multiple sclerosis disrupt normal neural communication by

A)destroying receptors on postsynaptic cells so that neurotransmitters cannot bind normally.
B)creating lesions in the blood-brain barrier that allow toxic substances to enter the brain from the bloodstream.
C)causing deterioration of the fatty substance that normally coats and insulates axons.
D)diminishing the activity of the sodium-potassium pumps that usually maintain the resting potential of neurons.

Question 8

The value of the membrane potential to which an axon must be depolarized to initiate an action potential is called the ________ potential for that neuron.

A)graded
B)resting
C)threshold
D)refractory

Question 9

In which of the following diseases is myelin damaged or lost?

A)Alzheimer's
B)Parkinson's
C)schizophrenia
D)multiple sclerosis

Question 10

At the resting state, a higher concentration of ________ is found outside a neuron and a higher concentration of ________ is found inside a neuron.

A)K+; Na+
B)Na+; K+
C)dopamine; serotonin
D)serotonin; dopamine

Question 11

The Hodgkin-Huxley cycle describes how the depolarization of the membrane causes voltage-gated sodium channels to ________, allowing ________ sodium ions to enter the cell. This change in sodium concentration then causes ________ of the cell.

A)close; fewer; further depolarization
B)close; fewer; repolarization
C)open; more; further depolarization
D)open; more; repolarization

Question 12

If you inserted a micropipette into a neuron without harming the cell and pumped in a small quantity of calcium ions, each of which carried two positive charges, how would this affect the membrane potential?

A)The membrane potential would become depolarized relative to the resting potential.
B)The membrane potential would become hyperpolarized relative to the resting potential.
C)There would be no change because calcium does not contribute to the resting potential.
D)There would be no change because the sodium-potassium pump would remove excess calcium from the cell.

Question 13

The ease with which a cell membrane will permit ions to cross is referred to as

A)the concentration gradient.
B)permeability.
C)the action potential.
D)conductivity.

Question 14

The two main classes of cells in the nervous system are

A)dendrites and axons.
B)axons and neurons.
C)neurons and glial cells.
D)glial cells and dendrites.

Question 15

Ouabain is a toxin that works by permanently inhibiting the activity of sodium-potassium pumps embedded in neuronal membranes. How would ouabain administration affect the resting potential of a neuron?

A)The magnitude of the resting potential would shift toward zero.
B)The resting potential would hyperpolarize toward a more negative value.
C)The resting potential would reverse to a positive, rather than a negative, value.
D)Application of ouabain would not affect the resting potential.

Question 16

The nodes of Ranvier are

A)vesicles of neurotransmitters, stored in presynaptic neurons.
B)little knobs attached by small necks to the surface of dendrites.
C)vesicles of calcium ions, stored in postsynaptic neurons.
D)points along axons that are not surrounded by myelin.

Question 17

The term concentration gradient refers to a difference in the

A)number of two different ion types within the neuron.
B)number of ions found on opposite sides of the cell membrane.
C)permeability of the membrane to one kind of ion compared to another.
D)permeability of the membrane at rest compared to during an action potential.

Question 18

Two main types of projections extend from the cell body of a neuron. ________ receive inputs from other neurons, while ________ send information to other neurons.

A)Synapses; glia
B)Axons; dendrites
C)Glia; synapses
D)Dendrites; axons

Question 19

If electrical currents on multiple dendrites sum together at the axon hillock, and the current flows across the neuronal membrane to the spike-triggering zone, what is likely to happen?

A)An action potential will be initiated.
B)A sodium-potassium pump will activate.
C)Hyperpolarization.
D)Saltatory conduction.

Question 20

The poison tetraethylammonium (TEA) interferes with normal neural communication. The toxin binds to and blocks voltage-gated potassium channels in the neuron cell membrane. Which of the following best describes the effects of TEA on the action potential?

A)The depolarization phase of the action potential fails to occur.
B)The repolarization phase of the action potential is blocked.
C)The refractory period of the action potential is shortened.
D)The action potential fails to be regenerated at the nodes of Ranvier.

Question 21

The effect of a particular neurotransmitter on postsynaptic neurons

A)is always either excitatory or inhibitory.
B)depends on the properties of the postsynaptic neuron.
C)may be modulated by the presence or absence of another neurotransmitter.
D)depends on the properties of the postsynaptic neuron and may be modulated by the presence or absence of another neurotransmitter.

Question 22

Cerebrospinal fluid (CSF) is produced in the lateral and third ventricles by the

A)dura mater.
B)substantia nigra.
C)globus pallidus.
D)choroid plexus.

Question 23

Which of the following statements best describes the immediate consequence of neurotransmitter molecules binding to ligand-gated ion channel receptors?

A)Voltage-gated channels in the cell membrane open and permit ion flow through the membrane.
B)The activity of the sodium-potassium pumps increases.
C)Calcium absorption into the axon terminal cell is triggered.
D)Neurotransmitter-containing vesicles bind to the inside of the axon terminal membrane.

Question 24

The role of calcium ions (Ca²⁺) in synaptic transmission is to

A)bind neurotransmitter molecules to the postsynaptic membrane.
B)mediate the release of neurotransmitter molecules from the presynaptic neuron.
C)repolarize the postsynaptic cell after transmission has been completed.
D)increase the activity of the sodium-potassium pumps in the presynaptic cell.

Question 25

Compare the following analogy to chemical synaptic transmission: Two postage companies use different methods for delivery. Company One's method is to send a delivery person out with packages that will be delivered directly to the address on the label. Company Two's method is to send a delivery person out to a transfer center, and a second driver will deliver the package to the address. Company One's method best compares to ___________________, while Company Two's method best compares to ___________________. Company ___ uses a faster method.

A)G protein-coupled receptors (GPCRs); ligand-gated ion channels; One
B)G protein-coupled receptors (GPCRs); ligand-gated ion channels; Two
C)ligand-gated ion channels; G protein-coupled receptors (GPCRs); One
D)ligand-gated ion channels; G protein-coupled receptors (GPCRs); Two

Question 26

Gray matter is to white matter as ________ are to ________.

A)gyri; sulci
B)glial cells; neurons
C)cell bodies; axon tracts
D)oligodendrocytes; Schwann cells

Question 27

The two main divisions of the central nervous system are the

A)forebrain and brainstem.
B)white matter and gray matter.
C)brain and spinal cord.
D)cerebral hemispheres and cerebellum.

Question 28

A gap junction is

A)the point where a neurotransmitter vesicle binds to the presynaptic membrane.
B)a connection between two sections of a G protein that plays a role in second-messenger cascades.
C)a transmembrane channel that connects the cytoplasm of two cells at an electrical synapse.
D)more likely to be found on the amino acids than on the biogenic amines.

Question 29

Which of the following sequences of steps best represents the order of events that occur during synaptic transmission?

A)binding of neurotransmitter at the postsynaptic membrane → diffusion of neurotransmitter across the synapse → release of neurotransmitter from the presynaptic cell
B)diffusion of neurotransmitter across the synapse → binding of neurotransmitter at the postsynaptic membrane → release of neurotransmitter from the presynaptic cell
C)release of neurotransmitter from the presynaptic cell → binding of neurotransmitter at the postsynaptic membrane → diffusion of neurotransmitter across the synapse
D)release of neurotransmitter from the presynaptic cell → diffusion of neurotransmitter across the synapse → binding of neurotransmitter at the postsynaptic membrane

Question 30

The specialized structures that comprise the midbrain control functions such as

A)hormone regulation.
B)visual reflexes.
C)memory.
D)emotional processing.

Question 31

Many drugs produce their effects by facilitating or interfering with neurotransmitters at synapses. Which of the following drugs would most likely increase the effect of serotonin?

A)a drug that binds to directly coupled serotonin receptors but does not change membrane permeability to ions
B)a drug that prevents the activity of an enzyme that breaks down serotonin molecules in the synaptic cleft
C)a drug that blocks the effect of Ca2+ ions
D)a drug that blocks the effect of a conditional neurotransmitter that normally facilitates the effect of serotonin

Question 32

Which of the following cells produce myelin in the peripheral nervous system?

A)astrocytes
B)microglia
C)oligodendrocytes
D)Schwann cells

Question 33

The ___________, which is comprised of _________, restricts the diffusion of certain molecules and microbes from the circulatory system, protecting the brain from chemical compounds that might otherwise interfere with neuronal activity.

A)sodium-potassium pump; astrocytes
B)blood-brain barrier; astrocytes
C)myelin sheath; oligodendrites
D)lipid bilayer; oligodendrites

Question 34

The difference between gray matter and white matter is that gray matter refers to ________, whereas white matter refers to ________.

A)protruding rounded surfaces; fissures and invaginations
B)fissures and invaginations; protruding rounded surfaces
C)cell bodies; axon tracts
D)axons; cell bodies

Question 35

Which of the following cells devour and remove damaged brain cells?

A)astrocytes
B)microglia
C)oligodendrocytes
D)Schwann cells

Question 36

Which of the following is NOT a mechanism for removing a neurotransmitter from the synaptic cleft?

A)diffusion of the neurotransmitter away from the synapse
B)active reuptake of the neurotransmitter back into the presynaptic terminal
C)enzymatic breakdown of the neurotransmitter in the synaptic cleft
D)transport of the neurotransmitter by ion channels into neighboring glial cells

Question 37

Consider the synapse shown schematically here. If neuron A causes neuron B to become hyperpolarized relative to B's resting state,

A)neuron B is more likely to fire its own action potential.
B)neuron B is less likely to release neurotransmitter molecules from its own axon terminal.
C)neuron B is more likely to absorb extracellular potassium through voltage-gated channels.
D)neuron B is less likely to absorb extracellular sodium through the sodium-potassium pump.

Question 38

The brainstem includes all of the following components EXCEPT the

A)medulla.
B)midbrain.
C)hypothalamus.
D)pons.

Question 39

The thick outer membrane that encloses the brain within the skull is the

A)gray matter.
B)white matter.
C)myelin sheath.
D)dura mater.

Question 40

Which of the following is a catecholamine?

A)gamma-aminobutyric acid (GABA)
B)glutamate
C)serotonin
D)norepinephrine

Question 41

Injury to the hypothalamus would most likely interfere with

A)hormone regulation.
B)motor control.
C)memory.
D)olfactory sensation.

Question 42

All of the following are advantages of a folded cerebral cortex EXCEPT:

A)The need for blood vasculature in the cortex is eliminated.
B)Neural conduction time between areas is reduced.
C)Neurons are brought into closer three-dimensional relationships.
D)More cortical surface can be packed into the skull.

Question 43

All of the structures listed here are major components of the basal ganglia EXCEPT the

A)globus pallidus.
B)amygdala.
C)caudate nucleus.
D)putamen.

Question 44

As a result of a brain injury to this diencephalic structure, a patient is experiencing disruptions in maintaining homeostasis of bodily states and endocrine control.

A)thalamus
B)hypothalamus
C)hippocampus
D)cingulate gyrus

Question 45

Which of the following functions is NOT mediated primarily by the hypothalamus?

A)endocrine system regulation
B)maintenance of homeostatic states in the body
C)relay of sensory information from the body to the cortex
D)hormone control

Question 46

The central sulcus is an anatomical landmark that separates the ________ lobe from the ________ lobe.

A)temporal; frontal
B)frontal; parietal
C)parietal; occipital
D)occipital; temporal

Question 47

The part of the thalamus that is most important in relaying information to the primary visual cortex is the

A)lateral geniculate nucleus.
B)superior colliculus.
C)medial geniculate nucleus.
D)inferior colliculus.

Question 48

The morphology of the brain of Albert Einstein revealed an unusual Sylvian fissure, the division that separates the ________ lobe from the ________ lobes.

A)occipital; frontal and parietal
B)temporal; frontal and parietal
C)frontal; temporal and occipital
D)parietal; temporal and occipital

Question 49

A patient has great difficulty in maintaining his posture, walking, and coordinating his movements. His brain injuries probably involve the

A)cerebellum.
B)corpus callosum.
C)superior colliculus.
D)third ventricle.

Question 50

As a result of a brain injury to the medial temporal lobes and neighboring subcortical structures, a patient exhibits a number of cognitive and behavioral changes. Of the following options, which is the LEAST likely to be affected?

A)memory
B)emotional processing
C)learning
D)somatosensation

Question 51

This brain structure is often called the gateway to the cortex because almost all sensory inputs synapse here before continuing to their primary cortical sensory areas.

A)hypothalamus
B)hippocampus
C)thalamus
D)amygdala

Question 52

A patient reports that she is functionally blind after a focal brain injury, even though her eyes and optic nerves are completely intact. Of the structures listed here, the most probable location for the brain injury is the

A)inferior colliculus.
B)lateral geniculate nucleus.
C)superior temporal lobe.
D)postcentral gyrus.

Question 53

The dorsal portions of the gray matter in the spinal cord carry

A)motor information.
B)sensory information.
C)motor and sensory information from the dorsal surface of the body.
D)sensory and motor information to the cerebellum.

Question 54

The corpus callosum

A)permits communication between the two cerebral hemispheres.
B)is the area of the cortex in which information about touch, pain, temperature, and limb position is processed.
C)separates the temporal lobe from the frontal and parietal lobes.
D)is a fluid-filled chamber that cushions and supports the brain.

Question 55

The most caudal lobe of the cerebral cortex is the ________ lobe.

A)frontal
B)temporal
C)occipital
D)parietal

Question 56

Communication between the two hemispheres of the brain occurs mainly through the

A)basal ganglia.
B)cingulate gyrus.
C)corpus callosum.
D)limbic system.

Question 57

Neurons in two different regions of Brodmann's cytoarchitectonic map always

A)use different types of neurotransmitters to communicate.
B)differ in cell morphology and organization.
C)lie inside different lobes of the cerebral cortex.
D)are separated by fissures in the cortex.

Question 58

The ___________________ is a system of structures that includes the ____________. This system has been implicated in ________________________.

A)limbic system; amygdala; emotion behavior
B)limbic system; putamen; motor preparation
C)basal ganglia; amygdala; emotion behavior
D)basal ganglia; hippocampus; motor preparation

Question 59

The term cytoarchitectonics refers to

A)how cells in one brain region appear morphologically and how they are arranged with respect to each other.
B)how assemblies of neurons function together and how they communicate with neighboring ganglia.
C)how different brain regions differ in volume and how they interact to produce complex cognitive phenomena.
D)how the brains of different animals differ from each other in gross anatomy and the evolutionary bases of these differences.

Question 60

The temporal lobe is to the occipital lobe as ________ is to ________.

A)touch; vision
B)touch; audition
C)audition; vision
D)audition; touch

Question 61

Dendrites, which are large treelike processes extending from a neuron, are said to be presynaptic.

Question 62

Which of the following best describes the reason for substantial growth of the human brain from birth to adulthood?

A)The birth of neurons and expansion of axons.
B)The absorption of cerebral fluid into the brain.
C)The formation of synapses and growth of dendritic trees.
D)The formation of new neurons.

Question 63

This type of early cell line is the precursor to the cells that will compose the nervous system.

A)blastula
B)gastrula
C)endoderm
D)ectoderm

Question 64

The cell body of a neuron contains the same machinery found in most cells, including a nucleus, ribosomes, and mitochondria.

Question 65

Of the following choices, the most anterior portion of the frontal lobes-the prefrontal cortex-is most critical to

A)processing information about pain, touch, and temperature.
B)executive functions.
C)the "what" visual pathway.
D)the "where" visual pathway.

Question 66

The primary auditory cortex is organized using a tonotopic map, which means that there is an orderly representation of

A)loudness.
B)frequency.
C)duration.
D)spatial location.

Question 67

Parts of the brain where metabolic activity is relatively high are characterized by

A)elevated regional blood flow.
B)increased cerebrospinal fluid production.
C)a high degree of myelination.
D)greater concentrations of calcium ions.

Question 68

The frontal lobe is ________ to the occipital lobe, whereas the temporal lobe is ________ to the parietal lobe.

A)posterior; superior
B)anterior; inferior
C)superior; caudal
D)inferior; rostral

Question 69

The cells in the brain that guide migrating neurons to their final locations are called

A)microglia.
B)radial glia.
C)oligodendrocytes.
D)ventricular cells.

Question 70

Action potentials are electrical signals that are conducted down the axon of a neuron.

Question 71

Which of the following statements regarding the prenatal development of the human nervous system is correct?

A)The brain develops from ectoderm cells, whereas the spinal cord develops from mesoderm cells.
B)Ectoderm cells are the precursors of the entire nervous system.
C)Glial cells are derived from endoderm cells, whereas neurons are derived from ectoderm cells.
D)Mesoderm cells are the precursors for all parts of the human nervous system.

Question 72

All of the following terms refer to the same cortical region that processes visual input EXCEPT

A)striate cortex.
B)area V1.
C)Heschl's gyrus.
D)Brodmann area 17.

Question 73

The volume of cortex that is not sensory or motor has traditionally been termed ________ cortex.

A)extrastriate
B)cognitive
C)association
D)equipotential

Question 74

The primary visual cortex, or V1, is located in

A)the striate cortex.
B)Brodmann area 41.
C)Heschl's gyrus.
D)the Sylvian fissure.

Question 75

A patient recently suffered a traumatic blow to the head. She reports that she is having social difficulties, such as adding inappropriate comments to conversations. She cannot seem to control these outbursts. Which area of her cortex is most likely affected?

A)the posterior frontal lobe
B)the anterior parietal lobe
C)the anterior frontal lobe
D)the posterior parietal lobe

Question 76

The term selective permeability refers to the fact that a cell membrane will allow some ions to pass through more readily than others.

Question 77

A team of scientists from California and Sweden (Eriksson et al., 1998) administered BrdU, a synthetic form of thymidine, to patients. Which of the following best summarizes the findings from these procedures?

A)Very few neurons are generated after birth.
B)Synaptogenesis and synapse elimination peak earlier in sensory cortex than in association cortex.
C)Brains of humans and rats are anatomically similar.
D)New neurons are produced in the adult human brain.

Question 78

____________________ refers to the process of rapid cell division that occurs early in development of the nervous system.

A)Neurulation
B)Neuronal proliferation
C)Neuronal migration
D)Neural determination

Question 79

The resting potential of a neuron is typically +40 to +90 millivolts (mV).

Question 80

The neocortex contains ______ cortical layers, with ________ typically being the input layer.

A)10; layer IV
B)10; layer I
C)six; layer IV
D)six; layer I