test banks 1-16

Question 1

Why are a broad perspective and an interdisciplinary approach required for understanding the brain?

Answer 1

Understanding the brain requires knowledge about many things, from the structure of the water molecule to the electrical and chemical properties of the brain.

Question 2

Galen’s study of sheep brains was the basis for a theory of brain function that prevailed for almost 1500 years. Which of the following represents this view?-

Answer 2

Localization of brain function in the cerebrum and cerebellum

Question 3

What is “mind–brain problem”?

Answer 3

Individually, human mental capacities exist in the mind that is outside the brain.

Question 4

What notion was displaced by the concept of nerves being described as wires?

Answer 4

Nerves are channels that communicate with the brain by the movement of fluids.

Question 5

The combined work of Bell and Magendie revealed a fundamental fact about the spinal nerves.

Answer 5

Spinal nerves are bundles of sensory and motor nerves, and in each sensory and motor nerve fiber, transmission is strictly one-way.

Question 6

For what purpose did Franz Joseph Gall study the dimensions of the human head?

Answer 6

To understand the propensity for certain personality traits

Question 7

On what basis did Broca defend functional localization of the brain?

Answer 7

By establishing a relationship between the production of speech and the left frontal lobe

Question 8

To whom can we attribute the theory that behavior is among the heritable traits that can develop?

Answer 8

Charles Darwin

Question 9

Which of the following is a correct explanation of a disorder that affects the nervous system?

Answer 9

Cerebral palsy is a motor disorder caused by damage to the cerebrum before, during, or soon after birth.

Question 10

A neuroscientist is investigating how different neural circuits in the brain analyze sensory information, form perceptions of the external world, make decisions, and execute movements. At what level of analysis is this research conducted?

Answer 10

Systems neuroscience level

Question 11

What is the rationale behind the use of animal models to understand the human brain?

Answer 11

The nervous systems of different species of animals and humans share many common mechanisms.

Question 12

How do neuroscientists identify the parts of the brain that are specialized for different behavioral functions related to the niche a species normally occupies?

Answer 12

By comparing the specializations of the brains of different species

Question 13

At which level of analysis do neuroscientists study the different types of neurons and their functions?

Answer 13

Cellular neuroscience

Question 14

What is the difference between replication and verification?

Answer 14

Replication is repeating the experiment in other subjects to rule out the possibility of chance. In verification, the experiment is repeated and the same observations are obtained by any scientist following the same protocol as the original observer.

Question 15

true or false: Galen suggested that the cerebrum, which was soft, should be the recipient of sensations. He was of the view that to form memories, sensations should be imprinted onto the brain. Thus, this must occur in the doughy cerebrum. Although the conclusion is right, the reason suggested by Galen is incorrect.

Answer 15

true

Question 16

true or false: Scientists during the seventeenth and eighteenth centuries proposed the structure–function relationship between the white matter and gray matter in the brain. According to this relationship, gray matter contained the fibers that bring information to and from the white matter.

Answer 16

false

Question 17

true or false: Rats are considered valuable models for the effects of psychoactive drugs on the nervous system.

Answer 17

true

Question 18

true or false: The Institutional Animal Care and Use Committee is formed of the animal rights
representatives.

Answer 18

false

Question 19

What does the “neuron doctrine” state?

Answer 19

individual cells communicate by contact and not continuity.

Question 20

What is a primary function of MAPs?

Answer 20

Regulate the function and assembly of microtubules

Question 21

Neurons comprise two main structures: axons and dendrites. What is a major difference between the two?

Answer 21

Dendrites receive incoming signals from other neurons, whereas axons carry the output of neurons.

Question 22

A scientist looks through a microscope at the structure of a neuron. The scientist notices a layer of molecules separating the neuron’s intracellular space from the extracellular space. What is this part of the neuron known as?

Answer 22

Neuronal membrane

Question 23

What do you understand by the term translation?

Answer 23

Assembling proteins from amino acids

Question 23

What is the most important function of the rough endoplasmic reticulum?

Answer 23

Site of protein synthesis

Question 24

What does the mitochondrion “inhale”?

Answer 24

Pyruvic acid

Question 25

Identify an important difference between the cytoplasm of the axon and that of the axon/ terminal.

Answer 25

There are large numbers of mitochondria in the axon terminal.

Question 26

What is the function of a neurotransmitter receptor in the dendritic membrane?

Answer 26

Detect neurotransmitters

Question 27

Identify the protein that helps anterograde transport move materials from the soma to the terminal.

Answer 27

Kinesin

Question 28

Which of the following is the largest of the cytoskeletal elements?

Answer 28

Microtubule

Question 29

What is retrograde axoplasmic transport?

Answer 29

Movement of material from axon terminal to soma

Question 30

Some neurons have long axons that stretch from one part of the CNS to another. What are these called?

Answer 30

Golgi type I neurons

Question 31

What is the region where the axon begins?

Answer 31

Axon hillock

Question 32

true or false: Molecular neurobiologists study the information contained in genes to determine the structure and functions of the neuronal proteins.

Answer 32

true

Question 33

true or false: Dendritic spines are sensitive to the quality of the environment experienced during early development.

Answer 33

true

Question 34

true or false: During transcription, transcription factors regulate the process of binding RNA polymerase to the promoter to initiate RNA synthesis.

Answer 34

true

Question 35

true or false: Ribosomes take raw material in the form of amino acids and manufacture proteins usingthe blueprint provided by the mRNA.

Answer 35

true

Question 36

A simple reflex requires the nervous system to perform three functions. Two of these functions are to collect and distribute information. What is the third function?

Answer 36

Integrate information

Question 37

What is resting membrane potential?

Answer 37

Difference in electrical charge across the membrane at rest

Question 38

What is capacitance?

Answer 38

Storage of electric charge

Question 39

Which of the following are the major charge carriers involved in the conduction of electricity in neurons?

Answer 39

Ions

Question 40

How do the lipids of the neuronal membrane contribute to the neuronal membranes potential?

Answer 40

These lipids form a barrier to water-soluble ions and water.

Question 41

Which factor other than the ionic concentration gradient determines the equilibrium potential for an ion?

Answer 41

Selective ionic permeability

Question 42

How do action potentials differ from passively conducted electrical signals?

Answer 42

Action potentials are signals of fixed size and duration; passively conducted signals are not signals of fixed size and duration.

Question 43

How does the sodium-potassium pump help maintain the resting membrane potential?

Answer 43

Pumps potassium ions in and sodium ions out

Question 44

What is the meaning of an ion's equilibrium potential?

Answer 44

Electrical potential difference that exactly balances an ionic concentration gradient

Question 45

What is the term used to describe the mechanism for the regulation of [K+]o by astrocytes?

Answer 45

Potassium spatial buffering

Question 46

Distinguish between the “head” and “tail” of phospholipids.

Answer 46

The phospholipid's “head” contains hydrophilic phosphate and “tail” contains a hydrophobic hydrocarbon.

Question 47

In which condition do astrocytes take up extracellular K+?

Answer 47

When extracellular potassium concentrations rise

Question 48

Which of the following factors determines the ion selectivity of specific ion channels?

Answer 48

Nature of the R groups lining the ion channel

Question 49

true or false: Both neurons and muscle cells have excitable membranes.

Answer 49

true

Question 50

true or false: Protein shape influences protein function.

Answer 50

true

Question 51

true or false: Peptide bonds are a chain of a single amino acid.

Answer 51

false

Question 52

true or false: The differences between amino acids result from the differences in the size and nature of the R groups.

Answer 52

true

Question 53

How long does an action potential last from the beginning of the rising phase to the end of the falling phase?

Answer 53

2 msec

Question 54

What is meant by the action potential threshold?

Answer 54

Critical level of depolarization required to trigger an action potential

Question 55

What is the absolute refractory period?

Answer 55

The time period of about 1 msec after an action potential before another one can be initiated

Question 56

The movement of what ion occurs in the rising phase of the action potential?

Answer 56

Inward Na+

Question 57

How does the sodium channel selectivity filter differentiate between Na+ and K+ ions?

Answer 57

The sodium channel admits a Na+ water complex, with the water serving as a molecular chaperone through the channel.

Question 58

How does tetrodotoxin (TTX) affect channels?

Answer 58

TTX blocks Na+ channels.

Question 59

How have toxins been used as a research tool?

Answer 59

To study the consequences of blocking action potentials

Question 60

How long does it take for a voltage-gated potassium channel to open?

Answer 60

Voltage-gated potassium channels open about 1 msec after the membrane is depolarized.

Question 61

What role do voltage-gated potassium channels play in the action potential?

Answer 61

Voltage-gated potassium channels restore negative membrane potential after the spike.

Question 62

How does myelin help increase conduction velocity?

Answer 62

It provides electrical insulation.

Question 63

Where is the spike-initiation zone in a typical neuron?

Answer 63

The axon hillock

Question 64

Why do action potentials travel in only one direction?

Answer 64

The membrane just behind the action potential is refractory due to inactivated sodium channels.

Question 65

What property of the voltage-gated potassium channels allows K+ ions to pass?

Answer 65

Depolarization causes the four polypeptide subunits specific to the voltage-gated K+ channel to twist into a shape that allows K+ ions to pass.

Question 66

Optogenetic techniques have been developed allowing researchers to do which of the following by introducing foreign genes into test animals?

Answer 66

Open ion channels in response to blue light

Question 67

true or false: The spike-initiation zone in most peripheral sensory neurons occurs near the sensory nerve ending.

Answer 67

true

Question 68

true or false: The size of the giant axon of the squid illustrates that neural pathways that are important for survival have unusually large axons.

Answer 68

true

Question 69

true or false: The firing frequency of action potentials reflects the magnitude of the depolarizing current.

Answer 69

true

Question 70

true or false: In myelinated axons, action potentials are conducted slowly. This type of action potential propagation is called saltatory conduction.

Answer 70

false

Question 71

true or false: Saxitoxin is a channel-blocking toxin produced by the dinoflagellates of the genus Gonyaulax.

Answer 71

true

Question 72

true or false: Neurons vary in shape, size, gene expression, and connections, but all have identical electrical properties.

Answer 72

false

Question 73

Identify the neuroscientists who first proved the existence of electrical synapses.

Answer 73

Edwin Furshpan and David Potter

Question 74

What types of cells can a neuron communicate with at a synapse?

Answer 74

Another neuron, muscle cell, or glandular cell

Question 75

What is the function of a gap junction between neurons?

Answer 75

Electrical synapse between the neurons

Question 76

What is the other name for dense-core vesicles?

Answer 76

Secretory granules

Question 77

Why are neuromuscular junctions such reliable synapses?

Answer 77

Because the axon terminal is large and the presynaptic terminal contains a large number of active zones

Question 78

What are transporters? What is their role?

Answer 78

Special proteins embedded in the vesicle membrane; responsible for concentrating neurotransmitters inside the vesicle

Question 79

Which of the following channels in the active zones of the synaptic terminal open when the membrane depolarizes and causes the release of synaptic vesicles?

Answer 79

Voltage-gated calcium channels

Question 80

Under what conditions are peptide neurotransmitters generally released from the synaptic terminal?

Answer 80

Only with high-frequency trains of action potentials

Question 81

What are second messengers?

Answer 81

Molecules that activate additional enzymes in the cytosol

Question 82

How are released neurotransmitters cleared from the synaptic cleft?

Answer 82

enzymatic destruction and diffusion

Question 83

How do nerve gases interfere with synaptic transmission at the neuromuscular junction?

Answer 83

By inhibiting the enzyme AChE

Question 84

What is synaptic integration?

Answer 84

A process by which multiple synaptic potentials combine within one postsynaptic neuron

Question 85

Quantal analysis shows that a single action potential at the neuromuscular junction causes an EPSP of 40 mV or more, compared to only a few tenths of a millivolt at many CNS synapses. What accounts for this difference?

Answer 85

A larger number of synaptic vesicles releasing neurotransmitter at the neuromuscular junction compared with CNS synapses

Question 86

What is the effect of activating G-protein-coupled neurotransmitter receptors?

Answer 86

Activate effector proteins such as ion channels or those that synthesize second messengers

Question 87

true or false: Protein phosphorylation can change the conformation of a protein, thereby changing its activity.

Answer 87

true

Question 88

true or false: If the postsynaptic cell is an interneuron that uses GABA as a neurotransmitter, the excitation of the cell will result in an action potential in its synaptic targets.

Answer 88

false

Question 89

true or false: The effectiveness of an excitatory synapse in triggering an action potential depends on how near the synapse is to the spike-initiation zone and the properties of the dendritic membrane.

Answer 89

false

Question 90

true or false: Second messengers can alter cellular metabolism by activating additional enzymes in the cytosol.

Answer 90

true

Question 91

true or false: The transmission of G-protein-coupled receptors involves only two steps: binding to the receptor protein and activation of G-proteins. True or false?

Answer 91

false

Question 92

Dale's principle states that a neuron has at least two different neurotransmitters. True or false?

Answer 92

false

Question 93

GABAergic neurons are the major source of synaptic inhibition in the nervous system. True or false?

Answer 93

true

Question 94

The amino acid tyrosine is the precursor for three different amine neurotransmitters: dopamine, norepinephrine, and epinephrine. True or false?

Answer 94

true

Question 95

Which side of the cerebellum is concerned with movements of the right hand?

Answer 95

right

Question 96

Which of the following regulates vital bodily functions such as breathing?

Answer 96

Brain stem

Question 97

Axons of the nervous system are described as afferent and efferent according to the direction in which they carry information. Which of the following represents an efferent projection?

Answer 97

Motor output from the spinal code

Question 98

At what point do the somatic sensory axons enter the spinal cord?

Answer 98

Dorsal roots