Physiological Final Ch 3

Front 1

The proper order of a reflex arc is:

Back 1

sensory neuron, interneuron, motor neuron

Front 2

Which of the following is NOT a factor in determining whether or not two EPSPs combine to reach threshold?

Back 2

threshold of the presynaptic cell

Front 3

Which of the following is TRUE about EPSPs?

Back 3

they decay over time and space

Front 4

EPSP

Back 4

Excitatory PostSynaptic Potential

Front 5

A graded depolarization is known as an?

Back 5

excitatory postsynaptic potential

Front 6

Which of the following would produce spatial summation?

Back 6

present two or more weak stimuli at the same time

Front 7

Temporal summation most likely occurs with:

Back 7

rapid succession of subthreshold excitation

Front 8

A temporary hyperpolarization is known as an?

Back 8

IPSP

Front 9

Why is the speed of conduction through a reflex arc slower than the speed of conduction of an action potential along an axon?

Back 9

Transmissions between neurons at synapses is slower than along axons

Front 10

The circuit from sensory neuron to muscle response is called:

Back 10

a reflex arc

Front 11

In a reflex arc, the coordination between contraction of certain muscles and relaxation of others is mediated by:

Back 11

interneurons

Front 12

Simultaneous weak stimuli at different locations produce a greater reflexive response than one of the stimuli by itself. What is this phenomenon called?

Back 12

spacial summation

Front 13

temporal summation is to ____, as spatial summation is to ____.

Back 13

time, location

Front 14

Which of the following would most likely result in an IPSP?

Back 14

chloride ions entering the cell

Front 15

To measure temporal summation in single cells, researchers:

Back 15

record depolarizations of the postsynaptic neuron

Front 16

Even at rest, most neurons have periodic production of action potentials, known as the:

Back 16

spontaneous firing rate

Front 17

A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not?

Back 17

when the interneuron sends excitatory messages to one it sends inhibitory messages to the other

Front 18

Which of the following is TRUE about the firing rates of neurons?

Back 18

EPSPs increase the frequency

Front 19

____ are specialized junctions between neurons.

Back 19

synapses

Front 20

What causes an EPSP?

Back 20

the opening of sodium channels

Front 21

Which of the following is NOT true about EPSPs?

Back 21

they operate on an all-or-one principle

Front 22

Which of the following patterns of post-synaptic excitation will most likely result in an action potential?

Back 22

rapid sequence of excitatory postsynaptic potentials

Front 23

Depolarization is to ____ as hyperpolarization is to ____.

Back 23

excitation, inhibitory

Front 24

On the basis of what evidence were the properties of synapses first inferred?

Back 24

behavioral observations

Front 25

What do temporal summation and spatial summation have in common?

Back 25

both enable a reflex to occur in response to a weak stimuli

Front 26

The primary difference between an EPSP and an action potential is that

Back 26

EPSPs are subthreshold events that decay over time and space

Front 27

What is the primary difference between temporal summation and spatial summation?

Back 27

spacial summation depends on contributions from one than more sensory neuron

Front 28

The “decision” for a neuron to fire is determined by the:

Back 28

the ratio of EPSPs to IPSPs

Front 29

Inhibitory synapses on a neuron:

Back 29

hyperpolarize the postsynaptic cell

Front 30

A certain weak stimulus produces no reflexive response, but a rapid repetition of that stimulus may produce such a response. What is this phenomenon called?

Back 30

temporal summation

Front 31

What ordinarily prevents extensor muscles from contracting at the same time as flexor muscles?

Back 31

inhibitory synapses in the spinal cord

Front 32

In most cases, how many neurotransmitters can activate a postsynaptic neuron?

Back 32

several transmitters with different synapses responding to different transmitters

Front 33

What is the function of the enzyme acetylcholinesterase?

Back 33

it breaks down acetylcholine

Front 34

What is the synaptic cleft?

Back 34

the gap between the presynaptic and postsynaptic neurons

Front 35

Hormones exert their effects:

Back 35

similarly to metabotropic neurotransmitters

Front 36

Large neurotransmitters (such as peptides) are synthesized in the:

Back 36

cell body

Front 37

The basic building blocks for the majority of neurotransmitters are:

Back 37

amino acids

Front 38

____ are a category of chemicals including adenosine and several of its derivatives.

Back 38

purines

Front 39

The primary method for disposal of peptide neurotransmitters is:

Back 39

they diffuse away

Front 40

What do dopamine, norepinephrine, and epinephrine share in common?

Back 40

they are all synthesized from the same amino acids

Front 41

A neurotransmitter receptor is:

Back 41

a protein embedded in the membrane

Front 42

What happens when a neurotransmitter is released by a presynaptic cell?

Back 42

the protein passively spreads across the synaptic cleft

Front 43

One of nitric oxide's functions is that it:

Back 43

increases blood flow to certain parts of the brain

Front 44

A metabotropic synapse, by way of its second messenger:

Back 44

can influence in much or all of the postsynaptic cell

Front 45

After a meal that was rich in the amino acid tryptophan, which neurotransmitter level would be increased the most?

Back 45

serotonin

Front 46

The neurotransmitter GABA exerts ____ effects, and its effects are almost always ____.

Back 46

ionotropic(affect the strength of contraction of the heart muscle), inhibitory

Front 47

"Transporter" proteins transport neurotransmitters:

Back 47

back to the presynaptic neuron

Front 48

In general, a single neuron releases ____ neurotransmitter(s), and can respond to ____ neurotransmitter(s).

Back 48

several, many

Front 49

What determines the effect that a neurotransmitter has on the postsynaptic neuron?

Back 49

the receptors on the postsynaptic neuron

Front 50

Ionotropic effects are characterized by?

Back 50

rapid short-lived effects

Front 51

A hormone is a chemical that is:

Back 51

conveyed by the blood to other organs whose activity it influences

Front 52

High concentrations of all neurotransmitters, except for NO, are stored in the:

Back 52

presynaptic terminal

Front 53

The second messenger communicates to areas:

Back 53

within the cell

Front 54

After serotonin or one of the catecholamine transmitters stimulates the postsynaptic receptor, most of the transmitter molecules:

Back 54

are reabsorbed by the presynaptic cell

Front 55

The presynaptic terminal stores high concentrations of neurotransmitter molecules in:

Back 55

vesicles

Front 56

Receptor molecules for neurotransmitters that exert metabotropic effects are proteins that bind to ____ outside the membrane, and attach to ____ inside the membrane.

Back 56

neurotransmitters, G-proteins

Front 57

Releasing hormones are synthesized in the ____, and released in the ____.

Back 57

hypothalamus, anterior pituitary

Front 58

Neurotransmitter is to ____ as cyclic AMP is to ____.

Back 58

first messenger, second messenger

Front 59

When an action potential reaches the end of an axon, it evokes the release of neurotransmitters by opening ____ channels in the axon terminal.

Back 59

calcium

Front 60

COMT and MAO are:

Back 60

enzymes that convert catecholamines into inactive chemicals

Front 61

What is the most unusual thing about the neurotransmitter nitric oxide (NO)?

Back 61

It's normally a poisonous gas

Front 62

The amino acid tryptophan, is the precursor to?

Back 62

serotonin

Front 63

A receptor can directly open a channel, exerting an ____ effect or it can produce slower but longer ____ effects.

Back 63

ionotropic, metabotropic

Front 64

Suppose a new neurotransmitter is identified that does not excite or inhibit postsynaptic cells, but affects the release of other neurotransmitters or the sensitivity of postsynaptic cells. This neurotransmitter would most likely be categorized as a(n):

Back 64

neuromodulator

Front 65

Although slower than an action potential, synaptic transmission is still relatively fast because:

Back 65

the synaptic cleft is very narrow

Front 66

Vesicles are located:

Back 66

in presynaptic terminals

Front 67

Compared to ionotropic effects, metabotropic effects are:

Back 67

slower and longer-lasting

Front 68

Acetylcholine is synthesized in the:

Back 68

presynaptic terminal

Front 69

The anterior pituitary is composed of ____, and the posterior pituitary is composed of ____.

Back 69

glandular tissue, neural tissue

Front 70

A new drug is discovered that affects the activity of enzymes. Which of the following stages of synaptic transmission is most likely to be affected?

Back 70

synthesis

Front 71

The neuron excretes neurotransmitter through its membrane by a process called:

Back 71

exocitosis

Front 72

Ionotropic effects:

Back 72

may depolarize or hyperpolarize the postsynaptic membrane.

ionotropic: affects the strength of the muscle contractions, especially the heart

Front 73

Reuptake is the absorption of:

Back 73

neurotransmitters by the presynaptic membrane

Front 74

The main advantage of a neuron releasing more than one neurotransmitter is that:

Back 74

it can send more complex messages

Front 75

Which of the following actions is most likely to be dependent on ionotropic effects?

Back 75

rapid muscle contractions

Front 76

All of the following are catecholamines EXCEPT?

Back 76

serotonin

Front 77

Loewi demonstrated that synapses operate by the release of chemicals. He did this by:

Back 77

collecting fluid from a stimulated frog's heart, transferring it to another frog and measuring the heart rate

Front 78

If you eat a food containing tryptophan, what can you consume with it to increase its entry to the brain?

Back 78

carbohydrates

Front 79

Adrenocorticotropic hormone (ACTH) controls:

Back 79

secretions of the adrenal cortex

Front 80

Which effect is consistently associated with a "second messenger"?

Back 80

metabotropic

Front 81

What provides the building blocks for synthesizing all neurotransmitters?

Back 81

substances found in the diet

Front 82

Reuptake is an alternative to which other process?

Back 82

enzymatic breakdown of other neurotransmitters

Front 83

The correct sequence of chemical events at a synapse is:

Back 83

synthesis, transport,release, reuptake

Front 84

What would be the effect of a drug that inhibits the action of the enzyme acetylcholinesterase?

Back 84

prolonged action of acetylcholine at its synapses

Front 85

Given a repetitive series of action potentials in a given neuron, we can expect that:

Back 85

many actions potentials will fail to release any neurotransmitters at all

Front 86

Nicotine directly stimulates receptors in the central nervous system and at nerve-muscle junctions. These nicotinic receptors are also receptors for which neurotransmitter?

Back 86

acetylcholine

Front 87

The effect of Ritalin (methylphenidate) on the synapse is most similar to that of:

Back 87

cocaine

Front 88

The stimulant effects of MDMA are likely due to actions at ____ synapses, while the hallucinogenic effects are likely to due to actions at ____ synapses.

Back 88

dopamine, serotonin

Front 89

Cannabinoid receptors are located on the:

Back 89

the presynaptic neuron

Front 90

Our brains respond to plant chemicals because:

Back 90

plants use chemicals similar to neurotransmitters

Front 91

Which of the following is NOT a likely effect of using marijuana?

Back 91

reduced risk of parkinsons

Front 92

A drug which produces excitement, alertness, elevated mood, and decreased fatigue is referred to as a:

Back 92

stimulant

Front 93

Cannabinoid chemicals (such as the active component of marijuana) affect synapses by

Back 93

decreasing the release of both glutamate and GABA

Front 94

At high doses, MDMA:

Back 94

destroys axons that release serotonin
MDMA (ecstasy)

Front 95

A drug that blocks the effects of a neurotransmitter is called a(n):

Back 95

antagonist

Front 96

A drug that mimics or increases the effects of a neurotransmitter is called a(n):

Back 96

agonist

Front 97

At the synapse, amphetamine:

Back 97

reverses the dopamine transporter

Front 98

Why are the withdrawal effects of marijuana usually less intense than other drugs?

Back 98

marijuana leaves the body slowly

Front 99

Endogenous cannabinoids act to:

Back 99

decrease neurotransmitter release from the presynaptic neurons

Front 100

At the synapse, cocaine:

Back 100

blocks the reuptake of dopamine

Front 101

Which drugs most closely resemble the neurotransmitter serotonin?

Back 101

hallucinogens

Front 102

Which neurotransmitter has been repeatedly connected with addictive drugs?

Back 102

dopamine

Front 103

What is one factor in determining whether a drug that readily attaches to a receptor will have agonistic or antagonistic effects?

Back 103

its efficacy

Front 104

Why is marijuana unlikely to interfere with breathing or heart rate?

Back 104

receptors for marijuana in those brain areas are absent

Front 105

Which effect would be considered to be agonistic?

Back 105

stimulating the release of neurotransmitters

Front 106

What effect do opiate drugs have on dopamine?

Back 106

they indirectly increase the amount of dopamine by blocking the transmitters that usually block dopamine

Front 107

Which is MORE characteristic of marijuana users than of cocaine users?

Back 107

impairment of attention and memory

Front 108

LSD and other hallucinogenic drugs probably exert their effects most directly on what part of the neuron?

Back 108

the postsynaptic receptors

Front 109

Cannabinoids are a class of chemicals that include:

Back 109

marijuana

Front 110

To say that a drug has an affinity for a particular type of receptor is to imply that the drug:

Back 110

binds to that receptor

Front 111

Which effect would be considered to be antagonistic?

Back 111

blocking the synthesis of neurotransmitters

Front 112

With respect to drug effects, "efficacy" means:

Back 112

the degree to which a drug modulates the activity of a receptor

Front 113

Anandamide and 2-AG are believed to be the naturally occurring neurotransmitters that bind to the same receptors as which drug?

Back 113

marajuana

Front 114

A certain drug user experiences intensified sensations and the illusion that time is passing slowly. He also experiences problems with attention and memory. These symptoms are most characteristic of the use of which drug?

Back 114

marijuana

Front 115

The chemicals used as neurotransmitters in humans are found in:

Back 115

apparently all or nearly all other species

Front 116

The "key into a lock" analogy best describes:

Back 116

a drug's affinity for a receptor

Front 117

The presynaptic terminal ordinarily reabsorbs released dopamine through a protein called:

Back 117

dopamine transporter

Front 118

A drug that relaxes a person and makes them less sensitive to pain is most likely a(n):

Back 118

opiate

Front 119

If a drug has high affinity and zero efficacy, what effect does it have on the postsynaptic neuron?

Back 119

antagonistic

Front 120

Why do cocaine and amphetamine produce similar effects?

Back 120

both increase the amount of dopamine in the synapses

Front 121

Why do the effects of certain transmitters, such as serotonin, vary from one synapse to another?

Back 121

there are several types of potsynaptic receptors for serotonin

Front 122

If a drug has high affinity and high efficacy, what effect does it have on the postsynaptic neuron?

Back 122

agonistic

Front 123

Drugs that grossly distort perception are known as:

Back 123

hallucinogens

Front 124

Autoreceptors monitor the:

Back 124

amount of neurotransmitters released

Front 125

When opiates block the activity of the locus coeruleus, this results in:

Back 125

decreased fear and memory

locus coeruleus "the dark blue spot": a small nucleus in the pons (part of the brain stem) that releases noradrenaline which is a stress horomone

Front 126

Which of the following activities is LEAST likely to stimulate intense dopamine release in the nucleus accumbens?

Back 126

running

Front 127

The effect of cannabinoids to reduce nausea is most likely mediated by ____ receptors.

Back 127

serotonin

Front 128

Opiate drugs bind to receptors in the brain for:

Back 128

endorphins

Front 129

The main difference between methylphenidate (Ritalin), when taken as a medication for attention deficit disorder, and cocaine, when taken as a drug of abuse, is that methylphenidate

Back 129

produces the same effects more slowly

Front 130

Pert and Snyder's discovery that opiates bind with certain receptors led to what other discovery?

Back 130

the endogenous chemicals that bind with those receptors

Front 131

The brain area most often linked to drug addiction is the:

Back 131

nucleus accumbens

Front 132

Methylenedioxymethamphetamine (MDMA) is also known as?

Back 132

ecstasy

Front 133

common drug to treat alcoholism that produces illness after consuming alcohol is:

Back 133

antabuse

Front 134

The effectiveness and side-effects of a drug vary from one person to the next. One reason for this is that:

Back 134

each drug tends to affect more than one synapse

Front 135

Activation of autoreceptors tends to:

Back 135

decrease further neurotransmitter release