Chapter 2

When an action potential reaches the end of an axon, the depolarization causes what ionic movement in the presynaptic cell? a. sodium out of the cell b. lithium out of the cell c. iron into the cell d. calcium into the cell

d: calcium into the cell 2.2

Specialized junctions between neurons are called ____. a. nodes of Ranvier b. spines c. dendrites d. synapses

d: synapses 2.1

Ionotropic effects are characterized by ____. a. rapid and short-lived effects b. rapid and long lasting effects c. excitatory effects only d. inhibitory effects only

a: rapid short-lived effects 2.2

Charles S. Sherrington was the first to infer the properties of ____. a. synapses b. the refractory period c. the sodium-potassium pump d. dendrites and axons

a: synapses 2.1

What is the synaptic cleft? a. the gap between the presynaptic neuron and the postsynaptic neuron b. a packet that stores neurotransmitter molecules for release c. a subthreshold depolarization mechanism d. the long-term storage location for calcium ions

a: the gap between the presynaptic neuron and the postsynaptic neuron 2.2

On the basis of what evidence were the properties of synapses first inferred? a. the electron microscope b. single-neuron recordings c. behavioral observations d. PET scans

c: behavioral observations 2.1

What is the proper ordering of a reflex arc? a. motor neuron, sensory neuron, interneuron. b. sensory neuron, motor neuron, interneuron. c. motor neuron, interneuron, sensory neuron. d. sensory neuron, interneuron, motor neuron. SIM

d: sensory neuron, interneuron, motor neuron 2.1

A temporary hyperpolarization is known as an ____. a. EPSP b. IPSP c. ISPS d. EPIP

b: IPSP 2.1

"Second messengers" carry their messages to ____. a. the presynaptic membrane b. areas within the postsynaptic cell c. areas within the presynaptic cell d. the surrounding glia

b: areas within the postsynaptic cell 2.2

An EPSP is a(n) ____. a. graded depolarization b. depolarization with a rebounding hyperpolarization c. graded hyperpolarization d. action potential in a reflex arc

a: graded depolarization 2.1

Neuropeptides are synthesized in the ____. a. postsynaptic terminal b. presynaptic terminal c. cell body d. dendrites

c: cell body 2.2

The primary method for disposal of peptide neurotransmitters is ____. a. inactivation b. reuptake by the presynaptic neuron c. diffusion d. reuptake by the postsynaptic neuron

c: diffusion 2.2

When a vertebrate animal contracts the flexor muscles of a leg, it relaxes the extensor muscles of the same leg. Sherrington considered this evidence for the existence of ____. a. spatial summation b. temporal summation c. inhibitory messages d. the delay in transmission at synapses

c: inhibitory messages 2.1

Receptor molecules for neurotransmitters that exert metabotropic effects are proteins that bind to ____ outside the membrane, and attach to ____ inside the membrane. a. calcium; potassium b. neurotransmitters; nicotine c. neurotransmitters; G-proteins d. adenosine; nitric oxide

c: neurotransmitters; G-proteins 2.2

In addition to influencing other neurons, ____ increases blood flow to a specific area of the brain. a. endorphins b. glycine c. nitric oxide d. acetylcholine

c: nitric oxide 2.2

Which neurotransmitter is released by stimulated neurons to dilate the blood vessels? a. endorphins b. glycine c. nitric oxide d. acetylcholine

c: nitric oxide 2.2

In a reflex arc, the coordination between contraction of certain muscles and relaxation of others is mediated by ____. a. glial cells b. motor neurons c. sensory neurons d. interneurons

d: interneurons 2.1

A receptor can directly open a channel and thereby exert a(n) ____ effect, or it can produce slower but longer ____ effects. a. gated; metabotropic b. ionotropic; gated c. metabotropic; ionotropic d. ionotropic; metabotropic

d: ionotropic; metabotropic 2.2

What is the function of the enzyme acetylcholinesterase? a. It synthesizes acetylcholine from the diet. b. It increases the sensitivity of the postsynaptic cell to acetylcholine. c. It blocks further release of the transmitter acetylcholine. d. It breaks acetylcholine down into components for recycling.

d: it breaks acetylcholine down into components for recycling 2.2

An action potential causes the release of neurotransmitters by ____. a. blocking potassium pores in the membrane b. opening chloride pores in the membrane c. blocking iron pores in the membrane d. opening calcium pores in the membrane

d: opening calcium pores in the membrane 2.2

Which terms refers to a chemical that binds to another chemical? a. ligand b. electrolyte c. vesicle d. autoreceptor

a: ligand 2.2

The amino acid tryptophan is the precursor to which neurotransmitter? a. dopamine b. endorphin c. serotonin d. nitric oxide

c: serotonin 2.2

Sherrington found that repeated stimuli within a brief time have a cumulative effect. He referred to this phenomenon as ____. a. temporal summation b. spatial summation c. synaptic summation d. saltatory summation

a: temporal summation 2.1

Dopamine and norepinephrine are classified as ____. a. second messengers b. purines c. proteins d. catecholamines

d: catecholamines 2.2

Which statement is TRUE about the spontaneous firing rates of neurons? a. EPSPs increase the frequency. b. EPSPs decrease the frequency. c. IPSPs increase the frequency. d. One EPSP equals the effect of two IPSPs.

a: EPSPs increase the frequency 2.1

Avoiding foods with lecithin, such as eggs and peanuts, would affect the levels of which neurotransmitter the most? a. acetylcholine b. serotonin c. GABA d. endorphin

a: acetylcholine 2. 2

The basic building blocks for the majority of neurotransmitters are ____. a. amino acids b. nitric oxide c. sugars d. carbohydrates

a: amino acids 2.2

"Transporter" proteins transport neurotransmitters ____. a. back into the presynaptic neuron b. across the synapse to the postsynaptic neuron c. across the synapse back to the presynaptic neuron d. to the appropriate receptor sites

a: back into the presynaptic neuron 2.2

One advantage of nitric oxide is that it ____. a. can be made by neurons efficiently b. is easily synthesized in a laboratory c. increases the growth of microglia d. safe for human cells in large quantities

a: can be made by neurons efficiently 2.2

COMT and MAO are ____. a. enzymes that convert catecholamines into inactive chemicals b. enzymes that make catecholamines c. neurotransmitters in the same group as serotonin d. the inactive fragments of catecholamines

a: enzymes that convert catecholamines into inactive chemicals 2.2

Depolarization is to ____ as hyperpolarization is to ____. a. excitation; inhibition b. inhibition; excitation c. increasing the threshold; decreasing the threshold d. decreasing the threshold; increasing the threshold

a: excitation; inhibition

The anterior pituitary is composed of ____ and the posterior pituitary is composed of ____. a. glandular tissue; neural tissue b. neural tissue; glandular tissue c. neural tissue; neural tissue d. glandular tissue; glandular tissue

a: glandular tissue; neural tissue 2.2

Inhibitory synapses on a neuron ____. a. hyperpolarize the postsynaptic cell b. weaken the cell's polarization c. increase the probability of an action potential d. move the potential closer to the cell's threshold

a: hyperpolarize the postsynaptic cell 2.1

What happens to acetylcholine after it attaches to a receptor on the postsynaptic cell? a. It is broken down into two components. b. It is reabsorbed intact by the presynaptic cell. c. It is metabolized by the postsynaptic cell as a source of energy. d. It continues to stimulate the postsynaptic neuron until replaced by another neurotransmitter.

a: it is broken down into two components 2.2

Which process indicates spatial summation? a. Present two or more weak stimuli at the same time. b. Start action potentials at both ends of one axon at the same time. c. Do not allow a flexor muscle to relax before stimulating it again. d. Present a rapid sequence of weak stimuli.

a: present two or more weak stimuli at the same time 2.1

A drug that inhibits the action of the enzyme acetylcholinesterase will have the effect of ____. a. prolonging the action of acetylcholine at its synapses b. decreasing the duration of action of acetylcholine at its synapses c. decreasing the synthesis of acetylcholine by the presynaptic cell d. increasing the synthesis of acetylcholine by the presynaptic cell

a: prolonging the action of acetylcholine at its synapses 2.2

What provides the building blocks for synthesizing all neurotransmitters? a. proteins found in the diet b. breakdown products of DNA c. breakdown products formed from other transmitters d. methane and ethanol

a: proteins found in the diet 2.2

Which pattern of post-synaptic excitation will most likely result in an action potential? a. rapid sequence of EPSPs b. rapid sequence of IPSPs c. large number of simultaneous IPSPs d. large number of simultaneous IPSPs and EPSPs

a: rapid sequence of EPSPs 2.1

The circuit from sensory neuron to muscle response is called ____. a. a reflex arc b. a synapse c. flexion d. extension

a: reflex arc 2.1

Exocytosis is the process by which neurotransmitters are ____. a. released from the presynaptic neuron b. synthesized c. destroyed d. secreted into synaptic vesicles

a: released from the presynaptic neuron 2.2

Hormones exert their effects ____. a. similarly to metabotropic neurotransmitters b. similarly to ionotropic neurotransmitters c. by attaching to special receptors on muscle fibers d. by being metabolized and converted via presynaptic cells

a: similarly to metabotropic neurotransmitters 2.2

Even at rest, most neurons have periodic production of action potentials, known as the ____. a. spontaneous firing rate b. excitatory firing rate c. all-or-none law d. law of compensation

a: spontaneous firing rate 2.1

Although slower than an action potential, synaptic transmission is still relatively fast because ____. a. the synaptic cleft is very narrow b. sodium ions are transported quickly c. neurotransmitters diffuse faster than electricity d. EPSPs travel faster than IPSPs

a: the synaptic cleft is very narrow 2.2

Temporal summation is to ____ as spatial summation is to ____. a. time; location b. EPSP; IPSP c. location; time d. depolarization; hyperpolarization

a: time; location 2.1

After one frog's heart has been stimulated, an extract of fluid from that heart can make a second frog's heart beat faster. What conclusion did Otto Loewi draw from these results? a. Transmission at synapses is a chemical event. b. The sympathetic and parasympathetic nervous systems are antagonistic. c. Transmission at heart muscle synapses is electrical. d. Hormones facilitate the actions of the nervous system.

a: transmission at synapses is a chemical event 2.2

Why is the speed of conduction through a reflex arc slower than the speed of conduction of an action potential along an axon? a. Transmission between neurons at synapses is slower than along axons. b. The longer an axon, the slower its velocity. c. Interneurons have thicker axons than other neurons. d. There are greater amounts of myelin involved in the reflex arc.

a: transmission between neurons at synapses is slower than along axons 2.1

A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not? a. When the interneuron sends excitatory messages to one, inhibitory messages go to the other. b. Both muscles are mechanically connected in a way that makes it impossible for both to contract at the same time. c. Such coordination is learned through prenatal movement. d. Both muscles are controlled by branches of the same axon.

a: when the interneuron sends excitatory messages to one, inhibitory messages go to the other 2.1

The research that firmly established synaptic communication as chemical was ____. a. Elliot's adrenaline mimicking sympathetic activation b. Loewi's transfer of fluid from stimulated frog hearts c. Sherrington's study of reflexes d. Eccles's measurement of IPSPs

b: Loewi's transfer of fluid from stimulated frog hearts 2.2

What do dopamine, norepinephrine, and epinephrine share in common? a. They all affect the same receptors. b. They are all synthesized from the same amino acids. c. They are all released by the same neurons. d. They all are gases.

b: are all synthesized from the same amino acids 2.2

Reuptake is an alternative to which other process? a. recycling of neurotransmitters b. breaking down neurotransmitters via an enzymatic process c. absorbing neurotransmitters by postsynaptic neurons d. re-releasing neurotransmitters from postsynaptic neurons

b: breaking down neurotransmitters via an enzymatic process 2.2

You are eating a food containing tryptophan. What can you consume with it to increase its entry to the brain? a. phenylalanine b. carbohydrates c. fats d. thiamine

b: carbohydrates 2.2

Loewi demonstrated that synapses operate by the release of chemicals by ____. a. applying adrenaline directly to the heart muscle b. collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate c. measuring the speed of a dog's reflexes while the dog was under the influence of various drugs d. applying an extract of marijuana in eye drops and discovering that it dilated the pupils

b: collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate 2.2

A hormone is a chemical that is ____. a. secreted by a gland to the outside world b. conveyed by the blood to other organs, whose activity it influences c. capable of activating or inhibiting muscle fibers d. a feedback message from the postsynaptic neuron to the presynaptic neuron

b: conveyed by the blood to other organs, whose activity it influences 2.2

An EPSP is to ____ as an IPSP is to ____. a. hyperpolarization; depolarization b. depolarization; hyperpolarization c. spatial summation; temporal summation d. temporal summation; spatial summation

b: depolarization; hyperpolarization 2.1

A neuron excretes neurotransmitters through its membrane by a process called ____. a. reuptake b. exocytosis c. endocytosis d. synaptic diffusion

b: exocytosis 2.2

Releasing hormones are synthesized in the ____ and released in the ____. a. anterior pituitary; bloodstream b. hypothalamus; anterior pituitary c. hypothalamus; posterior pituitary d. posterior pituitary; hypothalamus

b: hypothalamus; anterior pituitary 2.2

Glutamate opens sodium gates, enabling sodium ions to enter the postsynaptic cell. What type of effect is this? a. metabotropic b. ionotropic c. modulatory d. orthodromic

b: ionotropic 2.2

Increased permeability to ____ would most likely result in an IPSP. a. sodium b. potassium c. calcium d. bicarbonate

b: potassium 2.1

Increased permeability to which type of ion would most likely result in an IPSP? a. sodium b. potassium c. calcium d. bicarbonate

b: potassium 2.1

Sherrington studied ____, which are automatic muscular responses to stimuli. a. instincts b. reflexes c. inhibitions d. aversions

b: reflexes 2.1

Charles Sherrington would most likely agree with which statement about reflexes? a. The overall speed of conduction through a reflex arc is faster than conduction along an axon. b. Repeated stimuli occurring within a brief time can have a cumulative effect. c. Each neuron physically merges with the next one during a reflexive response. d. Excitatory synapses are more important than inhibitory synapses.

b: repeated stimuli occurring within a brief time can have a cumulative effect 2.1

What is the primary difference between temporal summation and spatial summation? a. Only spatial summation can produce an action potential. b. Spatial summation depends on contributions from more than one sensory neuron. c. Temporal summation produces a hyperpolarization instead of a depolarization. d. Spatial summation alters the response of more than one postsynaptic cell.

b: spatial summation depends on contributions from more than one sensory neuron

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? a. spatial summation b. temporal summation c. saltatory conduction d. synaptic combination

b: temporal summation 2.1

What causes an EPSP? a. the deactivation of cytoplasmic enzymes b. the opening of sodium channels c. the opening of potassium channels d. the deactivation of stress response pathways

b: the opening of sodium channels 2.1

Which statement is TRUE of EPSPs? a. They work in pairs to produce an action potential. b. They decay over time and space. c. They can be either excitatory or inhibitory. d. They occur because potassium gates open.

b: they decay over time and space 2.1

Which one of Sherrington's inferences about the synapse was WRONG? a. Transmission at a synapse is slower than transmission of impulses along an axon. b. Transmission at the synapse is primarily an electrical process. c. Synapses can be either excitatory or inhibitory. d. Synapses make spatial summation and temporal summation possible.

b: transmission at the synapse is primarily an electrical process 2.2

The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____. a. axons b. vesicles c. peptides d. dendrites

b: vesicles 2.2

Autoreceptors monitor the ____. a. number of action potentials b. extracellular sodium concentration c. amount of neurotransmitter released d. amount of reuptake

c: amount of neurotransmitter released 2.2

When an action potential reaches the end of an axon, it evokes the release of neurotransmitters by opening ____ channels in the axon terminal. a. chloride b. bicarbonate c. calcium d. oxygen

c: calcium 2.2

A metabotropic synapse, by way of its second messenger, ____. a. has effects localized to one point on the membrane b. can influence activity in much of the presynaptic cell c. can influence activity in much or all of the postsynaptic cell d. has minimal effect on the postsynaptic cell

c: can influence activity in much or all of the postsynaptic cell 2.2

Which process will most likely result in an IPSP? a. potassium ions entering the cell b. sodium ions entering the cell c. chloride ions entering the cell d. chloride ions leaving the cell

c: chloride ions entering the cell 2.1

What ordinarily prevents extensor muscles from contracting at the same time as flexor muscles? a. the ligaments and tendons that bind them together b. learned patterns of coordination in the cerebral cortex c. inhibitory synapses in the spinal cord d. control of both muscles by different branches of the same axon

c: inhibitory synapses in the spinal cord 2.1

The main advantage of a neuron releasing more than one neurotransmitter is that: a. if it runs out of one, it has others b. it can release different transmitters on different occasions c. it can send more complex messages d. it can release one from the axon's terminal and one from another location along the axon

c: it can send more complex messages

What makes nitric oxide unique among neurotransmitters? a. It is released before the action potential occurs. b. It is taken back up into the presynaptic neuron. c. It is a gas. d. It is an organelle.

c: it is a gas 2.2

Ionotropic effects ____. a. depolarize the postsynaptic membrane b. hyperpolarize the postsynaptic membrane c. may depolarize or hyperpolarize the postsynaptic membrane d. enhance the reabsorption of neurotransmitters

c: may depolarize or hyperpolarize the postsynaptic membrane 2.2

Spatial summation refers to ____. a. multiple weak stimulations that occur in rapid succession b. a decrease in responsiveness after repeated stimulation c. multiple weak stimulations that occur at the same time d. an increase in the strength of action potentials after repeated stimulation

c: multiple weak stimulations that occur at the same time 2.1

Vesicles are located ____. a. in postsynaptic terminals b. in dendrites c. in presynaptic terminals d. outside of the neuron in the extracellular fluid

c: presynaptic terminals 2.2

Which process is more typical of a metabotropic effect than an ionotropic effect? a. producing inhibitory effects on the postsynaptic cell b. influencing the speed of conduction by the postsynaptic cell c. producing long-lasting effects on the post-synaptic cell d. controlling sensory processes

c: producing long-lasting effects on the post-synaptic cell 2.2

The effect of a neurotransmitter on a postsynaptic neuron is determined by the ____. a. speed the action potential traveled down the axon b. number of branches of the presynaptic axon c. receptors on the postsynaptic membrane d. distance between the synapse and the cell body

c: receptors on the postsynaptic membrane 2. 2

Simultaneous weak stimuli at different locations produce a greater reflexive response than one of the stimuli by itself. What is this phenomenon called? a. Sherrington's law b. temporal summation c. spatial summation d. the all-or-none law

c: spatial summation 2.1

What determines whether a neuron has an action potential? a. only the number of EPSPs impinging on an axon b. only the number of IPSPs impinging on the dendrites c. the combined effects of EPSPs and IPSPs d. summation effects of IPSPs

c: the combined effects of EPSPs and IPSPs 2.1

What happens when a neurotransmitter is released by a presynaptic cell? a. It causes calcium to rush into the presynaptic neuron. b. It causes calcium to rush into the postsynaptic neuron. c. The neurotransmitter passively spreads across the synaptic cleft. d. The neurotransmitter is actively transported across the synaptic cleft.

c: the neurotransmitter passively spreads across the synaptic cleft 2.2

The "spontaneous firing rate" of a neuron refers to ____. a. its resting potential b. its rate of energy consumption c. its rate of producing action potentials even when it is not stimulated d. the velocity of its action potentials under normal conditions

c: the rate of producing action potentials even when it is not stimulated 2.1

Sherrington deduced that transmission at a synapse must be slower than conduction along an axon. This was based on what kind of evidence? a. temporal summation b. drugs that increase or inhibit activity at synapses c. the speed of reflexive responses d. differences in diameter between axons and dendrites

c: the speed of reflexive responses 2.1

A graded depolarization is known as an ____. a. EPIP b. IPSP c. ESPN d. EPSP

d: EPSP 2.1

The primary difference between an EPSP and an action potential is that ____. a. the magnitude of an action potential decreases as it travels along the membrane b. EPSPs occur without sodium ions entering the cell c. action potentials are always hyperpolarizations d. EPSPs are subthreshold events that decay over time and space

d: EPSPs are subthreshold events that decay over time and space 2.1

An IPSP represents ____. a. the location where a dendrite branches b. a gap in a myelin sheath c. a subthreshold depolarization d. a temporary hyperpolarization

d: a temporary hyperpolarization 2.1

Adrenocorticotropic hormone (ACTH) controls secretions of the ____. a. gonads b. mammary glands c. thyroid gland d. adrenal cortex

d: adrenal cortex 2.2

What do temporal summation and spatial summation have in common? a. Both involve the activity of only two neurons. b. Both require a response from the brain. c. Both depend on a combination of visual and auditory stimuli. d. Both enable a reflex to occur in response to weak stimuli.

d: both enable a reflex to occur in response to a weak stimuli 2.1

Insulin increases the entry of tryptophan into the brain by ____. a. weakening the blood-brain barrier b. converting tryptophan into a compound that more easily enters the brain c. increasing metabolic activity only in those areas of the brain that use tryptophan d. causing certain competing amino acids to enter other cells, outside the brain

d: causing certain competing amino acids to enter other cells, outside the brain 2.2

Activation of autoreceptors tends to ____. a. increase further neurotransmitter release b. stimulate GABA release c. increase sodium-potassium pump activity d. decrease further neurotransmitter release

d: decrease further neurotransmitter release 2.2

Many neurons release neuropeptides mostly from the ____. a. vesicles b. nodes c. axons d. dendrites

d: dendrites 2.2

The catecholamines include ____. a. epinephrine, norepinephrine, dopamine, and serotonin b. epinephrine, serotonin, and dopamine c. dopamine, serotonin, and acetylcholine d. epinephrine, norepinephrine, and dopamine

d: epinephrine, norepinephrine, and dopamine 2.2

Which category of chemicals includes adenosine and several of its derivatives? a. neuropeptides b. acetylcholine c. monoamines d. purines

d: purines 2.2

Which event is most likely to be dependent on ionotropic effects? a. drowsiness b. hormone release c. hunger d. rapid muscle contraction

d: rapid muscle contraction 2.2

Temporal summation most likely occurs with ____. a. infrequent, subthreshold excitation b. rapid succession of stimuli that each exceed threshold c. infrequent, inhibitory stimuli d. rapid succession of subthreshold excitation

d: rapid succession of subthreshold excitation 2.1

The "decision" for a neuron to fire is determined by the ____. a. number of EPSPs only b. spontaneous firing rate c. number of IPSPs only d. ratio of EPSPs to IPSPs

d: ration of EPSPs to IPSPs 2.1

To measure temporal summation in single cells, researchers ____. a. attach electrodes to the scalp b. insert an microelectrode into the scalp c. collect sodium and potassium ions from nearby glial cells d. record depolarizations of the postsynaptic neuron

d: record depolarizations of the postsynaptic neuron 2.1

In general, a single neuron releases ____ neurotransmitter(s) and can respond to ____ neurotransmitter(s). a. one; many b. dozens of; only one c. several; only one d. several; many

d: several; many 2.2

Compared to ionotropic effects, metabotropic effects are ____. a. quicker and briefer b. slower and briefer c. quicker and longer lasting d. slower and longer lasting

d: slower and longer lasting 2.2