Deck 3: The Brain and the Nervous System

Question 1

One thing that makes the study of the human brain so incredibly daunting is the fact that within the brain, the total number of neurons-the cells that act as information processors- has been estimated to be as high as __________.

A) 1 million
B) 1 billion
C) 100 billion
D) 500,000

Answer 1

100 billion

Question 2

Which of the following did NOT have a strong scientific influence during the 1500s and 1600s?

A) Descartes
B) Newton
C) Galileo
D) Von Helmholtz

Answer 2

Von Helmholtz

Question 3

Zach was in a car accident, and injured his brain. As a result of the car accident, he seems to have undergone a dramatic transformation from a calm professional to a wild and unpredictable individual. He is no longer able to plan or reason, and he shows great variation in his emotions throughout the day. As a result of the car accident, which part of Zach's brain was most likely injured?

A) his temporal lobe
B) his limbic system
C) his frontal lobe
D) his parietal lobe

Answer 3

his frontal lobe

Question 4

Descartes' view of action was radical and surprisingly straightforward. What he proposed was that __________.

A) every action brings a reaction
B) we act because we fear not acting
C) all action is reflex action
D) every action is a direct response to some event in the outside world

Question 5

In Descartes' conception, nonhuman animals are machines, but humans are not because only humans __________.

A) possess souls
B) have complex enough nervous systems to make it obvious that their actions are not governed only by reflexes
C) possess senses, nerves, and animal spirits
D) have a central switching mechanism
E) all of the above

Question 6

The Catholic Church forced Galileo to recant his suggestion that the Earth orbits around the sun. Descartes would probably have had similar trouble with the Church if he had __________.

A) suggested that people have reflexes
B) continued his study of evolution
C) not put a "ghost" in his machine
D) pursued his work in analytic geometry

Question 7

Which of the following statements accurately reflects the acceptance of the analogy of brain as machine?

A) It has always been accepted as a good analogy.
B) It is a good analogy for explaining motor functions, but does not reflect the idea of the mind.
C) It is a new and novel approach to understanding the brain.
D) The idea that our thoughts and feelings might be machinelike may be considered heretical both historically and contemporaneously by some people today.

Question 8

Which of the following statements characterizes the scientific thought of the 1500s and 1600s?

A) Human behavior is complex and mysterious and cannot be understood by science.
B) The soul's directives could not be the product of some machine-like system.
C) Natural phenomena can be understood through relatively straightforward scientific principles such as the reflex arc, acceleration, or the movement of planets.
D) Intellectual growth could explain natural phenomena of the world, but could not be similarly applied to human behavior.

Question 9

In the textbook's opening tour of the brain, the case of D.B. was described. D.B. had surgery to remove a benign tumor from his right occipital lobe. Following the surgery, D.B. reported that he __________.

A) could no longer hear
B) could no longer speak
C) had difficulty making plans
D) experienced a large blind spot in his left visual field

Question 10

Prior to the changes in scientific thought that characterized the 1500s and 1600s, human behavior was assumed to be __________.

A) easily explainable through scientific thought
B) explainable in scientific terms for motor behavior, but not cognitive behavior
C) explainable from Descartes' perspective, but not Newton's
D) unexplainable and mysterious

Question 11

Which area of the brain is found under the crown of your head?

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

Question 12

Which of the following commonly observed characteristics of human or animal behavior is inconsistent with Descartes' view on reflexes?

A) the withdrawal response upon touching a hot object
B) behavior (e.g., running) in the absence of any obvious stimulus
C) the existence of nerves that connect receptors and effectors to the brain
D) the fact that the same stimulus usually produces the same response

Question 13

Descartes' early forerunner of the reflex concept differs from our modern one because Descartes __________.

A) distinguished between sensory and motor nerves
B) posited the existence of the synapse
C) said that nerve impulses are electrochemical events
D) argued that the ultimate controller was the soul

Question 14

Which of the following brain functions would be most likely the first to be lost as we age?

A) those abilities and skills that are the last to form
B) those abilities and skills that form earliest
C) those abilities that are learned but not those that are innate
D) those skills and abilities that require language, but not those that require motor function

Question 15

Scientific advances during the 1500s and 1600s included the advances of __________.

A) Descartes, Newton, Kepler, and Galileo
B) Descartes, Pasteur, Darwin, and Newton
C) Descartes, Darwin, Newton, and Galileo
D) Descartes, Pasteur, Kepler, and Galileo

Question 16

René Descartes made his speculations about reflexes shortly after __________.

A) Darwin published his own speculations about the origin of species and the U.S. Civil War (1850s)
B) Freud had popularized his ideas about the unconscious and World War I (1910s)
C) Marco Polo traveled to China (about 1300)
D) Kepler and Galileo developed ideas about the movements of planets (1600s)

Question 17

The word reflex has its origin in __________.

A) Sherrington's work on synapses
B) Sherrington's studies of scratching in dogs
C) Descartes' belief that energy from the outside is reflected back by the nervous system to an animal's muscles
D) Descartes' belief that animals act as automatons, whereas people are rational and have souls

Question 18

Many processes in the brain functioned essentially mechanically, according to Descartes, but what truly governed our behavior, what made humans different from animals, what made reason and choice possible, was __________.

A) language
B) the ego
C) intelligence
D) the soul

Question 19

The word reflex has its origin in __________.

A) Descartes' belief that the energy from the outside is reflected back by the nervous system to an animal's muscles
B) Descartes' belief that animals act as automatons, whereas people are rational and have souls
C) Descartes' desire to explain coughing and sneezing without reference to the soul
D) Descartes' idea that the pineal gland mediates the relationship between the nonmaterial mind and the material brain

Question 20

In the textbook's opening tour of the brain, the case of J.S. was discussed. J.S. became ill with herpes simplex and encephalitis. As a result, he showed drastically altered language and memory abilities due to the resulting damage to his __________.

A) temporal lobe
B) limbic system
C) frontal lobe
D) parietal lobe

Question 21

Efferent signals are to __________ as afferent signals are to __________.

A) receptors; neurons
B) motor functions; sensory functions
C) neurons; receptors
D) sensory functions; motor functions

Question 22

The axon of a neuron __________.

A) contains the neuron's nucleus and all the elements needed for metabolic function
B) receives inputs or signals from many other neurons
C) sends signals to other neurons
D) holds the neuron in place

Question 23

You are looking at a neuron under a microscope and find the part that sends signals to other neurons. You have identified the __________.

A) axon
B) dendrites
C) cell body or soma
D) glia

Question 24

Which of the following is the smallest?

A) dendrite
B) synapse
C) axon
D) cell body

Question 25

Dendrite is to tree as __________ is to garden hose.

A) axon
B) synapse
C) ion
D) nucleus

Question 26

Which of the following is the most appropriate metaphor for a dendrite?

A) a ladder
B) a branch of a bush
C) a flower on the end of a long stem
D) a vacuum cleaner for synaptic transmitters

Question 27

What is the ratio of glial cells to neurons?

A) 1:1
B) 1:10
C) 4:1
D) 10:1

Question 28

The dendrites of a neuron __________.

A) contain the neuron's nucleus and all the elements needed for metabolic function
B) receive inputs or signals from many other neurons
C) send signals to other neurons
D) hold the neuron in place

Question 29

What is a glia?

A) the immaterial mind-stuff that controls reflexes, according to Descartes
B) a supersensitive brain scan that detects neurotransmitter activity in the midbrain
C) a type of cell in the brain
D) the gap between the sending cell and the receiving cell

Question 30

__________ are bundles of neurons that conduct excitation toward the brain or spinal cord.

A) Receptors
B) Effectors
C) Efferent nerves
D) Afferent nerves

Question 31

Sam picks up a hot cookie sheet and then quickly drops it as her body begins to respond to the heat sensations. The neurons responsible for sending the signal regarding the pain would be considered __________ neurons.

A) efferent
B) afferent
C) parasympathetic
D) somatic

Question 32

Which of the following is not part of a neuron?

A) axon
B) dendrites
C) cell body or soma
D) node of Ranvier

Question 33

The cell that specializes in sending and receiving information in the brain is called a __________.

A) neuron
B) glial cell
C) transducer cell
D) node of Ranvier

Question 34

You are looking at a neuron under the microscope. You find the area that contains the neuron's nucleus and all the elements needed for metabolic function. You have identified the __________.

A) axon
B) dendrites
C) cell body or soma
D) glia

Question 35

The soma or cell body of a neuron __________.

A) contains the neuron's nucleus and all the elements needed for metabolic function
B) receives inputs or signals from many other neurons
C) sends signals to other neurons
D) holds the neuron in place

Question 36

You are looking at a neuron under the microscope and identify the part that receives inputs or signals from many other neurons. You have identified the __________.

A) axon
B) dendrites
C) cell body or soma
D) glia

Question 37

__________ are bundles of neurons that conduct excitation from the brain or spinal cord.

A) Receptors
B) Effectors
C) Efferent nerves
D) Afferent nerves

Question 38

Nodes of Ranvier are important in __________.

A) speeding up the transmission of nerve impulses
B) shielding the synapse from extraneous chemicals
C) the synthesis of fatty tissue that makes up the myelin sheath
D) transducing mechanical stimuli into nerve impulses

Question 39

Neuropathic pain, a condition in which people suffer extreme pain in response to even mild touch, is likely due to __________.

A) glia releasing chemicals that increase the reactivity of neurons
B) glia releasing chemicals that decrease the reactivity of neurons
C) glia replacing chemicals that are typically released by neurons
D) glia blocking chemicals that are typically released by neurons

Question 40

Axon is to garden hose as __________ is to tree.

A) nerve impulse
B) synapse
C) dendrite
D) myelin sheath
E) nucleus

Question 41

What was the big advantage of studying nerve impulses in squid?

A) Axons in squid are plentiful.
B) Axons in squid have no resting potential, so it is easy to detect their nerve impulses.
C) Some axons in squid are huge.
D) Some axons in squid have no thresholds.

Question 42

Which of the following can be described as the gray matter of the human brain?

A) cell bodies
B) interneurons
C) unmyelinated axons
D) all of the above

Question 43

How can propagation speed be increased for a neuron?

A) wrapping myelin layers around the axon
B) increasing the number of neurons activated
C) increasing the amplitude of the action potential
D) removing the myelin layers around the axon

Question 44

The excitation threshold of most neurons __________.

A) is approximately +40 mV
B) changes depending on the size of the action potential
C) is approximately -70 mV
D) all of the above

Question 45

Propagation of a myelinated neuron __________.

A) occurs more slowly than an unmyelinated neuron
B) occurs only at the nodes of Ranvier
C) require lower thresholds to achieve an action potential than an unmyelinated neuron
D) all of the above

Question 46

Depolarization of a neuron refers to __________.

A) the type of neuron activated (e.g., low vs. high threshold neurons)
B) the loss of electrical charge that normally exists across the membrane
C) the period in which a neuron cannot fire immediately after an action potential
D) the movement of sodium out of the cell

Question 47

Which of the following refers to the bare portions of a myelinated axon?

A) nodes of Ranvier
B) glial cells
C) white matter
D) soma

Question 48

What is the name of the passageways through the cell membrane that allow only certain ions to pass?

A) ion pump
B) ion channels
C) myelin sheath
D) glia

Question 49

The ion pump in a neuron __________.

A) actively pumps ions into or out of the cell
B) moves sodium (Na+) out of the cell
C) moves potassium (K+) into the cell
D) all of the above

Question 50

Which of the following is the best analogy of propagation of the action potential?

A) a series of dominoes falling down
B) the telephone-game where one person tells the next a message
C) a gun firing
D) a chain letter

Question 51

Roberto is measuring the rate of neural transmission in two animals. Animal A has myelinated neurons, while animal B has unmyelinated neurons. Which of the following is likely to be true?

A) Action potentials will be largest in animal A.
B) Action potentials will be largest in animal B.
C) The rate of neural transmission will be faster in animal A.
D) The rate of neural transmission will be faster in animal B.

Question 52

White matter is composed primarily of __________, while gray matter is composed primarily of __________.

A) myelinated axons; cell bodies
B) cell bodies; unmyelinated axons
C) unmyelinated axons; cell bodies
D) cell bodies; dendrites

Question 53

During the refractory period, an action neuron __________.

A) absolutely cannot engage in an action potential
B) has more difficulty conducting an action potential
C) more easily conducts an action potential
D) shows faster depolarization across the axon

Question 54

Which of the following is NOT one of the primary functions of glia?

A) Glia have a central role in brain development.
B) Glia provide nourishment for neurons.
C) Glia are the primary mechanism for neurotransmitter communication.
D) Glia insulate the axon.

Question 55

The resting potential of a neuron __________.

A) is an electrical phenomenon unique to the squid giant neuron
B) refers to the electrical current spread associated with the action potential
C) is such that the inside of the neuron is negatively charged relative to the outside
D) refers to the electrical difference induced by the introduction of a microelectrode into the cell

Question 56

A neuron is stimulated by a stimulus that just achieves threshold. After an interval of a few seconds, a new stimulus is applied that is half as intense as the previous one. The resulting action potential will have what peak voltage?

A) 2 mV
B) 5 mV
C) 10 mV
D) There will be no action potential.

Question 57

The action potential consists of __________.

A) a transition from a negative charge (inside the neuron) to a persisting positive charge (inside)
B) a transition from a positive charge (inside) to a negative (inside) and a quick return to a positive charge (inside)
C) a transition from a negative charge (inside) to a positive (inside) and a quick return to a negative charge (inside)
D) the flow of negative ions into the cell followed by the pumping out of these negative ions from the inside of the axon

Question 58

New evidence suggests that, rather than merely offering passive support to neurons, glial cells may __________.

A) constitute a second, slow signaling system within the brain
B) be responsive to various electrical, chemical, and mechanical stimuli
C) be extensively networked to communicate with each other
D) all of the above

Question 59

Assume a physiologist has inserted a microelectrode at the arrow tip in the preceding diagram. When the neuron is at rest, the voltage recorded at the arrow tip will be __________.

A) zero millivolts (mV)
B) -70 mV
C) +50 mV
D) negative, neutral, or positive depending on what kind of neuron it is

Question 60

The brief period in which it is more difficult to launch a new action potential is called the __________.

A) action potential
B) depolarization period
C) ion channel
D) refractory period

Question 61

An above-threshold depolarizing current is applied to the cell, but it is slightly above the required threshold for the action potential. As a result, __________.

A) the action potential occurs more slowly
B) the action potential will be the same size and propagated at the same speed as if the depolarizing current was applied at threshold levels
C) the action potential occurs more quickly and is larger
D) the action potential will be smaller and propagated slightly slower than if the depolarizing current was applied at threshold levels

Question 62

Adjacent neurons __________.

A) do not actually touch, but are separated by a small gap
B) are held together by a structure called the synapse
C) are connected by dendrites at the synapse
D) use specialized chemicals called synaptic vesicles to communicate

Question 63

A researcher wants to determine whether a particular nerve specimen communicates via electrical or chemical activity. She places two specimens of the nerves into two containers filled with fluid. She electrically stimulates the first sample and elicits action potentials. She then takes fluid from that container and drips it into the other container containing the second specimen. If the nerve communicates chemically, this specimen should __________.

A) show no change
B) also show action potentials
C) show chemical but not electrical changes
D) none of the above; she cannot answer her question using this method

Question 64

Which of the following cannot be used for signaling the intensity of a stimulus?

A) the type of neuron activated (e.g., low vs. high threshold neurons)
B) the number of neurons activated
C) amplitude of action potentials
D) the frequency of firing along axons

Question 65

Synaptic vesicles are structures __________.

A) in which transmitters are stored
B) from which axon collaterals extend
C) in the shape of bulbs that protrude into the synaptic gap
D) found in the postsynaptic membrane

Question 66

What is wrong with the accompanying graph of an action potential?

A) Its peak is about 1,000 times too long.
B) Its peak is about 1,000 times too brief.
C) The signs ( + and - ) on the voltage axis are opposite of what they should be.
D) It should only go as high as -40 mV, not beyond it.
E) It does not appear to be "all-or-none."

Question 67

Transmission of information across the synaptic gap occurs by means of __________.

A) electrical charges
B) movement of synaptic vesicles
C) fine neurotubules
D) chemical diffusion

Question 68

The action potential is considered to be __________, while synaptic transmission is considered to be __________.

A) chemical; electrical
B) electrical; chemical
C) ionic; nonionic
D) very fast; very slow

Question 69

According to the all-or-none law, __________.

A) if one neuron fires, all the neurons fire
B) the action potential is larger if the stimulus is larger
C) the action potential will only occur if the stimulus meets or exceeds the threshold
D) the action potential will only occur if the stimulus meets or is below the threshold

Question 70

Acetylcholine is __________.

A) released at the junction between nerves and muscles
B) involved in sleep, mood, and arousal
C) a widely distributed inhibitory transmitter
D) important for reward and pleasure

Question 71

The postsynaptic neuron is __________.

A) before the synapse
B) after the synapse
C) inside the synapse
D) outside the synapse

Question 72

If you wanted to prevent a synapse from working, you might __________.

A) activate the axon leading to its synaptic knobs
B) block the release of the synaptic vesicles into the synapse
C) prevent the synaptic knobs from contacting the receptor surface of the dendrite
D) all of the above

Question 73

The neuron that receives the neurotransmitter after it has crossed the synapse is called the __________.

A) releasing neuron
B) sending neuron
C) postsynpatic neuron
D) presynaptic neuron

Question 74

The synapse is __________.

A) the area in which transmitters are stored.
B) the structure at the end of the neuron from which the neurotransmitter is released
C) the gap between neurons
D) found on the postsynaptic membrane

Question 75

Which of the following is the smallest?

A) synaptic vesicle
B) axon
C) dendrite
D) micrometer

Question 76

Above-threshold depolarizing currents are repeatedly applied at a rate of 1 per second to a single neuron. If we increase the frequency of stimulation to 10 per second, we can expect __________.

A) an increase in the number of action potentials per second
B) an increase in the magnitude of the action potential(s)
C) the number of action potentials per second to remain the same
D) none of the above

Question 77

Neurotransmitters __________.

A) are released into synaptic gaps
B) change the voltage of nearby neurons
C) are stored in tiny sacs
D) all of the above

Question 78

The presynaptic neuron is __________.

A) before the synapse
B) after the synapse
C) inside the synapse
D) outside the synapse

Question 79

Inhibition and excitation at synapses operate by __________.

A) some synapses being inhibitory, others excitatory
B) the release of one transmitter substance under some conditions and release of other transmitter substances under different conditions, all by the same neuron
C) taking in (inhibition) and releasing (excitation) transmitter substances
D) all of the above

Question 80

The neuron that releases the neurotransmitter into the synapse is called the __________.

A) releasing neuron
B) sending neuron
C) postsynpatic neuron
D) presynaptic neuron