Deck 13: Signal Transduction Mechanisms: I Electrical and Synaptic Signaling in Neurons

Question 1

The parts of the graph indicated at points C, D, and E represent

A)the refractory period.
B)repolarization.
C)sodium channel activity.
D)depolarization.
E)hyperpolarization.

Answer 1

B

Question 2

The somatic nervous system controls

A)smooth muscle.
B)cardiac muscle.
C)some glands.
D)skeletal muscles.
E)the brain and spinal cord.

Answer 2

D

Question 3

The resting potential of a particular nerve cell is - 66 mV. Depolarization of the membrane will shift the membrane potential toward

A)0 mV.
B)- 66 mV.
C)- 90 mV.
D)There will be no change.
E)There is not enough information to tell.

Answer 3

A

Question 4

You are examining a recently captured organism from another planet and are currently trying to deduce the types of neurotransmitters associated with the propagation of nerve impulses. You discover a very interesting neurotransmitter and find that, in spite of being alien, it is a derivative of the amino acid tyrosine. As a result, this novel neurotransmitter has to be classified as a(n)

A)neuropeptide.
B)serotinin analog.
C)GABA analog.
D)catecholamine.
E)acetylcholine analog.

Question 5

The stimulus for secretion of neurotransmitters into the synaptic cleft is an increase in

A)neurotransmitter levels.
B)chloride levels.
C)calcium levels.
D)potassium levels.
E)sodium levels.

Question 6

As a result of the way nerve impulses are propagated, they are unidirectional. Which of the following does NOT contribute to this phenomenon?

A)Unidirectional sodium and potassium channels open only toward the axon of the nerve cell.
B)Presynaptic neurotransmitters and postsynaptic receptors are separated.
C)Sensory processes are oriented in such a manner that the information is targeted to the dendrites of the nerve cell.
D)The time interval encompassed by the refractory period does NOT allow the impulse to travel in reverse.
E)none of the above

Question 7

Of all of the ions associated with generating the resting membrane potential, the permeability of the membrane to _ is the most important.

A)potassium ions
B)sodium ions
C)chloride ions
D)all of the above
E)none of the above

Question 8

The portion of the nervous system that is associated with the control of involuntary activities is the

A)autonomic nervous system.
B)automatic nervous system.
C)peripheral nervous system.
D)central nervous system.
E)somatic nervous system.

Question 9

Which equation best describes the relationship between ion gradient and equilibrium membrane potential for that ion?

A)Nernst
B)Steady- state
C)Katz
D)Goldman
E)Hodgkin

Question 10

You treat an organism with a drug that inhibits calcium permeability in nerve cells specifically. As a result, you expect to see

A)no depolarization of membranes.
B)failure to achieve the threshold necessary to stimulate a signal.
C)no repolarization of membranes.
D)no postsynaptic receptors.
E)presynaptic neurotransmitter release.

Question 11

The glial cell associated with phagocytosis to fight infection and remove debris are the

A)Schwann cells.
B)oligodendrocytes.
C)microglia.
D)astrocytes.
E)myelin sheath.

Question 12

Multiple sclerosis is a result of

A)excess amounts of myelin on nerve cells.
B)an immune system attack on nerve fibers.
C)the absence of myelin on nerve cells.
D)blocking the nodes on Ranvier.
E)having excess acetylcholine receptors.

Question 13

Catecholamines are synthesized by the

A)adrenal gland.
B)liver.
C)anterior pituitary gland.
D)skeletal muscle.
E)hypothalamus.

Question 14

An example of an inhibitory neurotransmitter is

A)dopamine.
B)GABA.
C)insulin.
D)epinephrine.
E)acetylcholine.

Question 15

The technique that allows one to record ion currents passing through individual channels is known as

A)ionophores.
B)ligand- gating.
C)patch- clamping.
D)voltage- gating.
E)ion sensors.

Question 16

Which of the following statements if FALSE regarding the nicotinic acetylcholine receptor?

A)Biochemical purification was aided by cobratoxin.
B)It binds one molecule of acetylcholine for activity.
C)The open channel allows an influx of sodium ions.
D)It is comprised of four large subunits.
E)The actions of acetylcholine can be mimicked by nicotine.

Question 17

Name for the phase at the end of an action potential when the membrane potential becomes more negative than it is at rest is the _ phase.

A)hyperpolarizing
B)refractory
C)repolarizing
D)threshold
E)depolarizing

Question 18

The maximum membrane potential that an ion gradient can produce is the

A)resting potential.
B)actualized potential.
C)equilibrium potential.
D)membrane potential.
E)action potential.

Question 19

Based on your knowledge of nerve transmission, this movement of ions will

A)stimulate a change in a postsynaptic membrane, if three channel events are combined.
B)not stimulate a change in the postsynaptic membrane.
C)stimulate a change in a postsynaptic membrane, if 50 channel events are combined.
D)generate a current resulting in membrane depolarization.
E)stimulate a change in a postsynaptic membrane.

Question 20

The sweetener aspartame is a known excitotoxin. With regard to nerve cells, ingestion of this substance results in chronic nerve stimulation. With your knowledge of action potentials, this toxin must

A)stimulate continual impulses at the cell body.
B)block the synaptic cleft.
C)stimulate continual impulses at the dendrite.
D)bind the nodes of Ranvier.
E)stimulate continual impulses at the presynaptic receptors.

Question 21

Which neurotransmitter is not an amino acid derivative?

A)dopamine
B)acetylcholine
C)GABA
D)histamine
E)serotonin

Question 22

The stimulation of a neuron by a signal may ultimately stimulate

A)gland cells.
B)smooth muscle cells.
C)another nerve cell.
D)skeletal muscle cells.
E)all of the above

Question 23

Synaptic vesicles are synthesized in the nerve _ .

Question 24

Exposure to sarin gas, a potent nerve gas, results in muscle paralysis. Therefore, sarin gas must interfere with which neurotransmitter?

A)serotonin
B)enkephalins
C)dopamine
D)GABA
E)glutamate

Question 25

Hyperpolarization of the postsynaptic nerve terminal

A)increases the chance than an action potenetial will be initiated.
B)decreases the chance than action potential will be initiated.
C)is stimulated by an influx of calcium ions.
D)does not affect the initiation of an action potential.
E)none of the above

Question 26

You stimulate a neuron response by adding a given amount of excitatory neurotransmitter mixed with a 6x higher concentration of an inhibitory neurotransmitter to the synaptic cleft. You expect that

A)as a result of neuronal integration, there will be an inhibitory signal.
B)excitatory responses will travel 1/6 as often as inhibitory ones.
C)as a result of neuronal integration, there will be an excitatory signal.
D)the neuron will be confused and will not respond to the signal.
E)inhibitory responses will travel 1/6 as often as excitatory ones.

Question 27

Upon transmission of a nerve signal to a muscle cell, is released from the sarcoplasmic reticulum through a gated channel.

Question 28

The kinesin ATPase is located within the of a nerve cell.

Question 29

Ions of would initiate the release of a neurotransmitter, such as acetylcholine, via
into the synaptic cleft.

Question 30

An _ of a nerve cell is the temporary depolarization and repolarization of the cell membrane.