Unit D Practice Quiz

The most common neurotransmitter in the brain is ________. A) glycine B) acetylcholine C) serotonin D) GABA

d. GABA

(true/false) A lack of extracellular Ca2+ would cause increased release of neurotransmitters.

false

(true/false) A patient with Parkinson disease will have difficulty initiating skeletal muscle movements because the nigrostriatal dopamine system, degenerated in Parkinson disease, is part of the primary motor cortex.

false

(true/false) All axons in the PNS have a myelin sheath.

false

(true/false) An inactivated ion channel will respond to a stronger than normal threshold stimulus.

false

(true/false) During the absolute refractory period, a supramaximal stimulus can bring the cell to threshold.

false

(true/false) Release of ACh at parasympathetic effectors is always stimulatory.

false

(true/false) Somatic motor neurons innervate involuntary effectors.

false

(true/false) The greater the number of depolarization regions on an axon, the faster the action potential will be conducted.

false

The average resting membrane potential of an axon is ________. A) −70 mV B) −85 mV C) 0 mV D) +30 mV

a. -70 mV

As the intensity of a stimulus increases, more axons will become activated. This process is called ________. A) threshold B) refraction C) recruitment D) None of the choices are correct.

c. recruitment

Cells supporting neuron cell bodies in ganglia are termed ________. A) astrocytes B) ependymal cells C) satellite cells D) Schwann cells

c. satellite cells

What is NOT true of the relative refractory period? A) Na+ channels are inactivated. B) Many Na+ channels are returning to a closed state. C) K+ is moving out of the axon through its open channels. D) A strong stimulus could cause a depolarization.

a. Na+ channels are inactivated

An axon will depolarize only if the membrane potential reaches between -70mV and -55mV. This follows the ________. A) all-or-none law B) recruitment law C) graduated law D) threshold law

a. all-or-none law

The synapses which occur between axons of presynaptic cells and dendrites of postsynaptic cells are called ________. A) axodendritic B) axosomatic C) myoneural D) axoaxonic

a. axodendritic

Botulism toxin prevents release of ACh, causing ________. A) flaccid paralysis B) hemiplegia C) spastic paralysis D) None of the choices are correct.

a. flaccid paralysis

Chemical synapses ________. A) have a delayed impulse transmission B) utilize gap junctions C) occur when two nerve cells are in direct contact with each other D) do not require the release of neurotransmitters

a. have a delayed impulse transmission

Which type of cell of the CNS is phagocytic? A) Microglia B) Satellite cells C) Ependymal cells D) Oligodendrocytes

a. microglia

The term "white matter" refers to ________. A) myelinated axons in the CNS B) myelinated axons in the PNS C) nonmyelinated cell bodies and dendrites in the CNS D) nonmyelinated axons in the CNS

a. myelinated axons in the CNS

The most abundant neuropeptide in the brain is ________. A) neuropeptide Y B) neuropeptide Z C) substance P D) CCK

a. neuropeptide Y

Relaxation of cerebral blood vessels would be stimulated by excessive ________ activity. A) nitric oxide B) acetylcholine C) norepinephrine D) glutamate

a. nitric oxide

Temporal summation ________. A) occurs when a single neuron releases neurotransmitter rapidly B) occurs because of the convergence of many neurons on a single postsynaptic cell C) only involves excitatory postsynaptic potentials D) only involves inhibitory postsynaptic potentials

a. occurs when a single neuron releases neurotransmitter rapidly

What type of autonomic fibers release ACh at effectors? A) Parasympathetic B) Sympathetic C) Somatic D) Sensory

a. parasympathetic

The myelin sheaths of PNS neurons are produced by ________. A) Schwann cells B) oligodendrocytes C) ependymal cells D) leukocytes

a. schwann cells

What neurotransmitter is used by neurons with cell bodies in the raphe nuclei along the midline of the brainstem? A) Serotonin B) Dopamine C) Glycine D) GABA

a. serotonin

Muscarinic ACh receptors are found in all of the following locations EXCEPT ________. A) skeletal muscle B) smooth muscle C) cardiac muscle D) glands

a. skeletal muscle

What is present at the axon hillock that allows the production of action potentials? A) Voltage-gated channels B) Ligand-gated channels C) Muscarinic receptors D) Chemical-gated channels

a. voltage-gated channels

Muscarinic ACh receptors act through ________ activation of K+ channels. A) cGMP B) G-protein C) M-protein D) ATP

b. G-protein

Cholinergic fibers use ________ as the neurotransmitter. A) norepinephrine B) acetylcholine C) dopamine D) serotonin

b. acetylcholine

Sensory neurons ________. A) are multipolar, and carry impulses toward the CNS B) are pseudounipolar, and carry impulses toward the CNS C) are bipolar, and carry impulses away from the CNS D) are multipolar, and carry impulses away from the CNS

b. are pseudounipolar, and carry impulses away from the CNS

Acetylcholine can induce hyperpolarization by ________. A) binding to nicotinic receptors B) binding to muscarinic receptors C) binding to α-adrenergic receptors D) binding to β-adrenergic receptors

b. binding to muscarinic receptors

Neurotransmitter release would be inhibited by ________. A) stimulating repolarization of the axon terminal B) blocking Ca2+ influx in the axon terminal C) blocking repolarization of the axon terminal D) stimulating protein kinase activity

b. blocking Ca+2 influx in the axon terminal

Excitatory postsynaptic potentials are produced in the brain primarily by ________. A) glycine B) glutamic acid C) gamma-aminobutyric acid D) benzodiazepines

b. glutamic acid

Acetylcholine usually induces an excitatory postsynaptic potential when binding to ________ receptors and an inhibitory postsynaptic potential when binding to some ________ receptors. A) NMDA; nicotinic B) nicotinic; muscarinic C) muscarinic; NMDA D) muscarinic; nicotinic

b. nicotinic; muscarinic

Spatial summation ________. A) occurs when a single neuron releases neurotransmitter rapidly B) occurs because of the convergence of many neurons on a single postsynaptic cell C) only involves excitatory postsynaptic potentials D) only involves inhibitory postsynaptic potentials

b. occurs because of the convergence of many neurons on a single postsynaptic cell

The myelin sheaths of CNS neurons are produced by ________. A) Schwann cells B) oligodendrocytes C) ependymal cells D) leukocytes

b. oligodendrocytes

Conduction of an action potential in a myelinated axon is called ________. A) point to point conduction B) saltatory conduction C) refractory conduction D) cable conduction

b. saltatory conduction

Nitric oxide ________. A) is a chemical messenger activating adenylate cyclase B) stimulates the dilation of blood vessels C) is produced from L-asparagine D) All of the choices are correct.

b. stimulates the dilation of blood vessels

The minimum depolarization needed to open Na+ gates is called the ________. A) repolarization B) threshold C) refractory period D) all-or-none law

b. threshold

From which amino acid are dopamine, norepinephrine, and epinephrine all derived? A) Histidine B) Tyrosine C) Tryptophan D) Serine

b. tyrosine

Ion channels that open in response to depolarization are called ________. A) ion-gated channels B) voltage-gated channels C) stimulation-gated channels D) potential-gated channels

b. voltage-gated channels

ATP and adenosine can act as neurotransmitters ________. A) when no ACh is available B) when released by adrenergic neurons during sympathetic activation C) after being used for energy by the cell D) All of the choices are correct.

b. when released by adrenergic neurons during sympathetic activation

Which of the following is NOT an action needed for glutamate to open ion channels? A) NMDA receptor must bind to glycine. B) The membrane must be partially depolarized from the action of a different neurotransmitter. C) Cl- must pass through the open channel. D) Mg2+ is released from NMDA channel to open it.

c. Cl- must pass through the open channel

During an action potential ________. A) Na+ efflux causes depolarization B) K+ influx causes repolarization C) Na+ influx causes depolarization D) K+ influx causes after-hyperpolarization

c. Na+ influx causes depolarization

What is needed to return a membrane to its resting membrane potential, with all ions in the correct locations? A) Influx of negatively charged ions into the cell B) Outflow of Na+ ions via passive ion channels C) Na+/K+ pump action D) Outflow of K+ ions via passive ion channels

c. Na+/K+ pump action

A drug that blocked ________ channels would prevent neuron ________. A) K+; depolarization B) Na+; hyperpolarization C) Na+; depolarization D) Ca2+; repolarization

c. Na+; depolarization

Action potentials would be conducted most rapidly by ________. A) a 10 mm diameter myelinated axon B) a 10 mm diameter unmyelinated axon C) a 40 mm diameter myelinated axon D) a 40 mm diameter unmyelinated axon

c. a 40 mm diameter myelinated axon

Depolarization of an axon is a positive feedback mechanism because ________. A) as more sodium channels open, the membrane potential decreases B) as more potassium channels open, the membrane potential decreases C) as more sodium diffuses into the axon, the more voltage-gated potassium channels open D) as more sodium diffuses into the axon, the more voltage-gated sodium channels open

c. as more sodium diffuses into the axon, the more voltage-gated potassium channels open

The blood-brain barrier results mostly from the action of ________, a type of neuroglia. A) ependymal cells B) microglia C) astrocytes D) oligodendrocytes

c. astrocytes

Which division of the nervous system innervates involuntary effectors? A) Central nervous system B) Somatic nervous system C) Autonomic nervous system D) Associative nervous system

c. autonomic nervous system

Neurotransmitters ________. A) are released by endocytosis B) bind to voltage-gated channels C) bind to chemically regulated channels D) are actively transported across the synaptic cleft

c. bind to chemically regulated channels

In order to prevent a patient from experiencing pain, local anesthetics must ________ in sensory neurons, which would prevent an action potential. A) inhibit the release of acetylcholine B) bind to potassium channels C) bind to sodium channels D) bind to calcium channels

c. bind to sodium channels

What type of neural pathway involves one neuron forming synapses with several postsynaptic neurons? A) Convergent B) Oscillating C) Divergent D) Plastic

c. divergent

Which type of cell lines the ventricles of the brain and help produce cerebrospinal fluid? A) Microglia B) Satellite cells C) Ependymal cells D) Oligodendrocytes

c. ependymal cells

Mutation of the N-methyl-D-aspartate (NMDA) receptor would affect the ability of ________ to regulate neural function. A) acetylcholine B) epinephrine C) glutamate D) nitric oxide

c. glutamate

Which of the following is NOT classified as a catecholamine? A) Norepinephrine B) Epinephrine C) Histamine D) Dopamine

c. histamine

Where is glycine released? A) In the PNS B) From the motor neurons innervating skeletal muscles C) In the CNS D) At the diaphragm

c. in the CNS

How do neurons code for a greater response? A) Greater amplitude of stimuli B) Greater Na+ concentration gradient C) Increased frequency of stimuli D) More active Na+/K+ pump

c. increased frequency of stimuli

At what region of the neuron are action potentials first produced? A) Dendrites B) Cell body C) Initial segment of an axon D) Axon hillock

c. initial segment of an axon

Chemicals that stimulate action potentials in postsynaptic cells are called ________. A) hormones B) enzymes C) neurotransmitters D) neurotrophins

c. neurotransmitters

Which ion's movement is responsible for repolarization? A) Influx of K+ B) Influx of Na+ C) Outward diffusion of K+ D) Outward diffusion of Na+

c. outward diffusion of K+

The membrane of resting nerve cells is more permeable to ________ ions than ________ ions. A) sodium, potassium B) calcium, potassium C) potassium, sodium D) chloride, potassium

c. potassium, sodium

Unlike chemical synapses, electrical synapses ________. A) are the method of connection between adjacent neurons B) allow communication between cells with larger distances between the membranes C) provide adjacent cells with the ability to act in a coordinated fashion D) are not dependent on the movement of ions across a plasma membrane

c. provide adjacent cells with the ability to act in a coordinated fashion

What type of receptors will bind ATP and adenosine? A) Cotransmitter receptors B) Pyrimenergic receptors C) Purinergic receptors D) None of the choices are correct.

c. purinergic receptors

What is the predominant effect of stimulation of nicotinic-gated channels? A) Stimulation due to outflow of K+ ions B) Inhibition due to outflow of K+ ions C) Stimulation due to influx of Na+ ions D) Inhibition due to influx of Cl- ions

c. stimulation due to influx of Na+ ions

If a cell's membrane is not excitable, this means that ________. A) the cell is a neuron B) the cell cannot be depolarized under any conditions C) the cell cannot vary the permeability of the membrane to specific ions D) the cell does not have a measurable voltage

c. the cell cannot vary the permeability of the membrane to specific ions

Choose the incorrect statement regarding EPSPs. A) They are graded responses. B) They are capable of summation. C) They have a refractory period. D) They are initiated by neurotransmitters.

c. they have a refractory period

A bundle of axons in the CNS is called a ________. A) nerve B) bundle C) tract D) neuron

c. tract

Serotonin is synthesized from the amino acid ________. A) alanine B) glycine C) tryptophan D) serine

c. tryptophan

Since the action potential "leaps" from node to node in a myelinated axon, ________. A) myelinated axons need far less Na+ channels than unmyelinated axons B) action potentials move faster if the nodes are farther apart C) Na+ movement within the myelin sheath is possible D) Na+ channels are not present between the nodes

d. Na+ channels are not present between the nodes

Synaptic vesicles are docked to the plasma membrane of the axon terminal by a protein complex called ________. A) boutons B) connexins C) synaptotagmins D) SNARE

d. SNARE

Histamine is able to ________. A) act as a neurotransmitter to cause skeletal muscle contraction B) act as a hormone that inhibits gastric secretion C) act as a neurotransmitter in the brain to cause drowsiness D) act as a regulator in inflammation and allergies

d. act as a regulator in inflammation and allergies

What event(s) could cause presynaptic inhibition? A) Inactivation of Ca2+ channels B) A second neuron causes a reduction in neurotransmitter release from another neuron C) Removal of SNARE complexes D) All of the choices are correct.

d. all of the choices are correct

Which of the following are natural analgesics? A) Endorphins B) Enkephalins C) Dynorphins D) All of the choices are correct.

d. all of the choices are correct

Neurotransmitter action could be prevented, or disrupted, if a drug or other agent ________. A) increased the expression of CAMs in the postsynaptic membrane B) decreased the distance between the pre- and postsynaptic membranes C) decreased the concentration of SNARE complexes in the postsynaptic cell D) blocked voltage-gated Ca2+ channels in the presynaptic membrane

d. blocked voltage - gated Ca+2 channels in the presynaptic membrane

Synaptic transmission using acetylcholine would be disrupted by ________. A) curare B) botulinum toxin C) strychnine D) Both curare and botulinum toxin are correct.

d. both curare and botulinum toxin are correct

Hyperpolarization in the postsynaptic cell is caused by ________. A) excitatory postsynaptic potentials B) inhibitory postsynaptic potentials C) movement of K+ out of the cell D) Both inhibitory postsynaptic potentials and movement of K+ out of the cell are correct.

d. both inhibitory postsynpatic potentials and movement of K+ out of the cell are correct

What type of neuron is found entirely in the CNS? A) Sensory neuron B) Interneuron C) Association neuron D) Both interneuron and association neuron are correct.

d. both interneurons and association neuron are correct

Which gas(es) can function as a neurotransmitter? A) carbon dioxide B) nitric oxide C) carbon monoxide D) Both nitric oxide and carbon monoxide

d. both nitric oxide and carbon monoxide

The period of time when Na+ channels are recovering from their inactive state and K+ channels are still open is the ________. A) repolarization B) absolute refractory period C) relative refractory period D) Both repolarization and relative refractory period are correct.

d. both repolarization and relative refractory period are correct

Acetylcholine ________. A) is always an excitatory neurotransmitter B) can bind to adrenergic receptors C) is an inhibitory neurotransmitter released by motor neurons D) can bind to nicotinic receptors

d. can bind to nicotinic receptors

A patient is prescribed an MAO inhibitor by their doctor. Knowing the actions of MAO inhibitors, this patient's diagnosis may be ________. A) hypertension, since MAO inhibitors block the release of norepinephrine from sympathetic axons B) hypertension, since MAO inhibitors block the degradation of norepinephrine at the synapse C) depression, since MAO inhibitors block the binding of serotonin to postsynaptic cells D) depression, since MAO inhibitors block the degradation of serotonin at the synapse

d. depression, since MAO inhibitors block the degradation of serotonin at the synapse

Catecholamines activate postsynaptic cells by ________. A) inhibition of adenylate cyclase B) increased Ca2+ influx into the target cell C) inhibition of calmodulin D) increased production of cyclic AMP

d. increased production of cyclic AMP

Inhibition of neuropeptide Y synthesis would ________. A) induce euphoria B) induce obesity C) stimulate leptin secretion D) inhibit eating

d. inhibit eating

Cocaine is particularly dangerous for patients with cardiovascular disease, or hypertension, because ________. A) it blocks the reuptake of serotonin and dopamine, causing excessive bouts of euphoria B) it inhibits the degradation of norepinephrine, causing coronary artery constriction C) it blocks membrane sodium channels, causing increased EPSPs D) it blocks the reuptake of norepinephrine, causing increased heart rate

d. it blocks the reuptake of norepinephrine, causing increased heart rate

What is NOT true of conduction through dendrites and cell bodies of neurons? A) It creates EPSPs. B) It is spread by cable properties. C) EPSPs can summate to reach threshold. D) It generates action potentials in the cell body.

d. it generates potentials in the cell body

Choose the incorrect statement about norepinephrine. A) It is released in both the central and peripheral nervous systems. B) It is released by sympathetic neurons to smooth muscle, cardiac muscle, and glands. C) Norepinephrine pathways are stimulated by amphetamines. D) It is released from adrenergic neurons in the parasympathetic nervous system.

d. it is released from adrenergic neurons in the parasympathetic nervous system

Curare is a competitive ACh antagonist at ________ ACh receptors. A) muscarinic B) NMDA C) kainate D) nicotinic

d. nicotinic

Action potential transmission in the PNS is decreased if which cells are damaged? A) Astrocytes B) Microglia C) Oligodendrocytes D) Schwann cells

d. schwann cells

If the binding of muscarine to its receptor in the heart causes the beta-gamma complex of the G-protein to bind to a K+ channel, ________. A) the K+ channel will close, leading to depolarization B) the K+ channel will open, leading to depolarization C) the K+ channel will close, leading to hyperpolarization and inhibition D) the K+ channel will open, leading to hyperpolarization and inhibition

d. the K+ channel will open, leading to hyperpolarization and inhibition

(true/false) An EPSP is conducted in a decremental fashion to the axon hillock, where voltage-gated Na+ and K+ channels are opened. This creates an action potential in the first segment of the axon.

true

(true/false) An inhibitory postsynaptic potential could be produced by a neurotransmitter that opens Cl- channels.

true

(true/false) Both depolarization and repolarization are produced by the diffusion of ions down their concentration gradient.

true

(true/false) Both excitatory and inhibitory postsynaptic potentials undergo summation.

true

(true/false) CCK (cholecystokinin) may act as a neurotransmitter in the brain to promote feelings of satiety.

true

(true/false) Conduction without decrement means that action potentials transmitted down an axon will not decrease in amplitude.

true

(true/false) Glycine and GABA act as inhibitory neurotransmitters in the CNS because they bind to Cl- channels on the postsynaptic membrane.

true

(true/false) Norepinephrine binding to a receptor stimulates the activity of adenylate cyclase.

true

(true/false) Since sensory neurons for muscle position are the fastest conducting neurons, they would have a larger diameter than sensory neurons for touch, pain or pressure.

true

(true/false) The nicotinic ACh receptor is a ligand-gated channel.

true

(ture/false) Parkinson disease is associated with the loss of dopaminergic neurons.

true