Physiology Chapter 2

Front 1

A cup of sugar is dumped into a gallon of hot water. After 30 minutes, we will expect that the process of _______ will ensure that the sugar molecules are evenly distributed throughout the water.Select one:a. anterograde transport

b. diffusion

c. retrograde transport

d salinity

e. electrostatic pressure

Back 1

diffusion

Front 2

Which of the following is true regarding the action potential (AP)?

Select one:

a. The AP amplitude is higher for an intense signal.

b. The AP is conducted along the dendrite.

c. The AP is an all-or-none electrical event

d. The AP amplitude depends on its location along the axon.e. The AP is conducted faster in unmyelinated nerve cells

Back 2

The AP is an all-or-none electrical event

Front 3

The normal order of activation during neuronal transmission is

a. cell body --> axon --> dendrite --> axon terminal.

b. axon terminals --> cell body --> axon --> dendrite.

c. dendrite --> axon terminal --> cell body --> axon.

d. axon --> dendrite --> cell body --> axon terminals.

e. dendrite --> cell body --> axon --> terminal butto

Back 3

dendrite --> cell body --> axon --> terminal button.

Front 4

A(n) _______ will be recorded from a nerve cell whose membrane potential rises above threshold.

a. downward shift of the threshold of excitation

b. local potential

c. upward shift of the membrane threshold

d. action potential

e. long-term change in the membrane potential

Back 4

action potential

Front 5

The _______ is the voltage level at which an action potential is triggered in a patch of axon membrane.

a. refractory period

b. hyperpolarization event

c. resting membrane potential

d. rate level

e. threshold of excitation

Back 5

threshold of excitation

Front 6

The difference in electrical charge between the inside and the outside of the axon membrane is defined as the _______ potential.

a. membrane

b. action

c. locald. axon

e. glial

Back 6

membrane

Front 7

_______ are negatively charged particles.Select one:

a. Electrolytes

b. Transmitters

c. Cations

d. Anions

e. Solvents

Back 7

Anions

Front 8

The function of a _______ in a giant squid physiology experiment is to _______.

a. microelectrode; compare the electric charge of the interior with that of the exterior

b. voltmeter; compare the electric charge of the interior with that of the exterior

c. microelectrode; inject potassium ions into the axon

d. microelectrode; dampen the electric charge within the axon

e. voltmeter; stimulate the interior of the axon

Back 8

voltmeter; compare the electric charge of the interior with that of the exterior

Front 9

As a consequence of the activity of the sodium-potassium transporters,

a. extracellular sodium concentrations are kept low.

b. extracellular potassium concentrations are kept very high.

c. very little energy is required to maintain ionic differences across the membrane.

d. intracellular sodium concentrations are kept very high.

e. intracellular sodium concentrations are kept low.

Back 9

intracellular sodium concentrations are kept low.

Front 10

The nervous system codes for variation in the intensity of incoming sensory stimuli by variations in the _______ of a neuron.

a. resting membrane potential

b. repolarization rate

c. firing rate

d. total amplitude of the action potential

e. speed of conduction of action potentials

Back 10

firing rate

Front 11

A substance that forms oppositely charged particles when dissolved into water would be termed a(n)

a. ion.

b. anion.

c. molecule.

d. cation.

e. electrolyte.

Back 11

electrolyte.

Front 12

The specialized protein molecules located in the axon membrane that can open or close are termed

a. voltage transporters.

b. ion channels.

c. autoreceptors.

d. sodium-potassium transporters.

e. receptors.

Back 12

ion channels

Front 13

Which of the following events restores the membrane potential from the peak of the action potential back down to the resting level?

a. Chloride ions move into the cell.

b. Potassium ions move into the cell.

c. Protein anions move out of the cell.

d. Potassium ions move out of the cell.

e. Sodium ions move into the cell.

Back 13

Potassium ions move out of the cell

Front 14

A change in the axon membrane potential from -70 mV to -90 mV would be termed a(n)

a. excitatory local potential.

b. depolarization.

c. hyperpolarization.

d. action potential.

e. threshold potential.

Back 14

. hyperpolarization.

Front 15

The process by which similarly charged particles repel each other and are thus moved within a medium is termed

a. diffusion.

b. electrostatic pressure.

c. refraction.

d. diffraction.

e. carrier-mediated transport.

Back 15

electrostatic pressure.

Front 16

Movement of _______ ions _______ the axon would be induced by the force of diffusion.

a. chloride; out of

b. potassium; into

c. sodium; out of

d. organic; into

e. sodium; into Feedback

Back 16

sodium; into

Front 17

The interior of a neuron at rest

a. is at the same voltage potential as the outside.

b. has the same ionic concentrations as the outside.

c. has a lower potassium concentration than outside.

d. is negatively charged relative to the outside.

e. has a higher sodium concentration than outside.

Back 17

. is negatively charged relative to the outside

Front 18

Which of the following is true of ion distribution across the axon membrane?

a. Sodium ions are more concentrated outside the axon membrane.

b. Chloride ions are more concentrated inside the axon membrane.

c. Potassium ions are more concentrated outside the cell membrane.

d. Sodium ions are more concentrated inside the axon membrane.

e. The action potential is the balance point between diffusion and electrostatic pressure.

Back 18

Sodium ions are more concentrated outside the axon membrane

Front 19

A neuron membrane potential moves from -90 mV to -80 mV in response to a brief stimulation. We would term this change in potential as a(n)

a. resting potential.

b. action potential.

c. depolarization.

d. inhibitory local potential.

e. hyperpolarization.

Back 19

c. depolarization

Front 20

Match up the correct receptor type and effect:

a. ionotropic; direct opening of an ion channel

b. metabotropic; second-messenger effects are specific to neuronal communication

c. ionotropic; more time required to open an ion channel

d. metabotropic; rapid short-lived effects on ion channels

e. ionotropic; G protein activation leads to activation of a second-messenger

Back 20

ionotropic; direct opening of an ion channel

Front 21

An EPSP will be produced when a ligand

a. opens a potassium channel.

b. closes a sodium channel.

c. opens a sodium channel.

d. closes a calcium channel.

e. closes a chloride channel.

Back 21

opens a sodium channel.

Front 22

In order to produce a depolarization or hyperpolarization of the postsynaptic membrane, neurotransmitters

a. are released into the synapse from the cisternae.

b. alter ion channel activity for minutes.

c. open ion channels in the postsynaptic membrane.

d. act through ionotropic receptors to activate a second-messenger.

e. diffuse widely in the brain to exert changes in metabolism.

Back 22

. open ion channels in the postsynaptic membrane.

Front 23

With regard to release of neurotransmitter in the brain, "kiss and run" refers to the situation in which the vesicle

a. releases most of its contents into the cleft and the vesicle remains attached to the presynaptic membrane.

b. releases most of its contents into the cleft after which the vesicle breaks away from the presynaptic membrane and is refilled.

c. closes before releasing any molecules and then moves to the cell interior.

d. merges completely with the presynaptic membrane.

e. remains open until the next action potential.

Back 23

releases most of its contents into the cleft after which the vesicle breaks away from the presynaptic membrane and is refilled.

Front 24

Neuromodulators

Select one:a. mostly involve presynaptic receptors

b. directly elicit postsynaptic potentials.

c. are usually amino acids.

d. are usually found in small vesicles in the axon terminal buttons.

e. diffuse widely to affect many neurons.

Back 24

diffuse widely to affect many neurons

Front 25

The postsynaptic potentials induced by acetylcholine are ended via

a. reuptake of acetylcholine.

b. disruption of the nicotinic postsynaptic receptor.

c. facilitation of acetylcholine release.

d. enzymatic degradation via acetylcholinesterase.

e. inhibition of acetylcholine synthesis.

Back 25

enzymatic degradation via acetylcholinesterase

Front 26

A drug that inactivates the enzyme acetylcholinesterase would be expected to

a.terminate the effects of acetylcholine in the synapse.

b. impair the synthesis of acetylcholine.

c. activate the presynaptic autoreceptor for acetylcholine.

d. prolong the effects of acetylcholine in the synapse.

e. speed up the synthesis of acetylcholine.

Back 26

prolong the effects of acetylcholine in the synapse.

Front 27

Autoreceptors are located on the _______ and detect _______.

Select one:

a. postsynaptic membrane; the presence of calcium ions located in the synapse

b. presynaptic membrane; the presence of calcium ions in the synapse

c. presynaptic membrane; the amount of second messenger activity in the postsynaptic cell

d. presynaptic membrane; the transmitter released by that neuron

e. presynaptic membrane; a different transmitter released by another neuron

Back 27

d. presynaptic membrane; the transmitter released by that neuron Correct

Front 28

Synaptic vesicles are produced in the _______.

Select one:

a. neuron soma

b. neuron lysosomes

c. astrocytes

d. dendrites

e. glial cells

Back 28

neuron soma

Front 29

The largest number of small vesicles would be expected to be located within the _______ of a neuron.

Select one:

a. axon hillock

b. postsynaptic membrane

c. dendritic spines

d.release zone

e. soma

Back 29

release zone Correct

Front 30

Signals are carried across the synapse by

Select one:

a. the sodium-potassium pump.

b. the secretion of transmitter molecules into the synapse.

c. the transfer of ions from one cell to another

.d. direct electrical connections between the two cells.

e. carrier molecules.

Back 30

b. the secretion of transmitter molecules into the synapse

Front 31

Neurotransmitter release from the presynaptic membrane is triggered by the

Select one:

a. opening of channels within the microtubules.

b. arrival of an EPSP at the axon terminal c.hyperpolarization of the axon membrane.

d. influx of calcium ions into the axon terminal.

e. activation of the sodium-potassium pumps. Incorrect

Back 31

influx of calcium ions into the axon terminal.

Front 32

An IPSP will be produced when a ligand

Select one:

a. opens a calcium channel.

b. opens a potassium channel.

c. opens a sodium channel.

d. closes a calcium channel.

e. closes a sodium channel

Back 32

b. opens a potassium channel. Correct

Front 33

Which of the following is true of metabotropic receptors?

a. Hormone receptors are found in all tissues except brain.

b. Neuromodulators are ligands that come from outside the body.

c. Receptors are insensitive to drugs.

d. The effects of hormones do not involve receptor activation.

e. Neurotransmitters act on binding sites on receptors to exert their effects

Back 33

Metabotropic receptors are slower than ionotropic receptors.

Front 34

After a vesicle fuses with the presynaptic membrane and releases its contents into the synaptic cleft, the membrane is

Select one:

a. incorporated into the mitochondria.

b. incorporated into the postsynaptic membrane.

c. recycled to form new vesicles.

d. degraded and the debris removed from the axon terminal.

e. destroyed by astrocytes.

Back 34

c. recycled to form new vesicles.

Front 35

Match up the correct receptor type and effect.

Select one:

a. metabotropic; rapid opening of a single ion channel

b. ionotropic; more time required to open an ion channel

c. metabotropic; G protein activation leads to activation of a second-messenger

d. metabotropic; direct opening of an ion channel

e. metabotropic; rapid short-lived effects on ion channels

Back 35

metabotropic; G protein activation leads to activation of a second-messenger

Front 36

The term _______ is derived from the word meaning "little bladder."

Select one:

a. vesicle

b. storage poo

c. mitochondria

d. neuritee.

e. cisternae

Back 36

vesicle Correct

Front 37

Presynaptic facilitation is associated with _______ synapses and involves a(n) _______ in the amount of transmitter released per action potential.

Select one:

a. gap junction; decrease

b. gap junction; increase

c. axodendritic; decrease

d. axosomatic; increasee. axoaxonic; increase

Back 37

. axoaxonic; increase

Front 38

Action potentials are generated at the _______ and are conducted along the _______.

Select one:

a. terminal buttons; dendrite

b. dendrite; glial membrane

c. axon hillock; axon

d. axon button; glial membrane

e. axon; dendrite

Back 38

axon hillock; axon

Front 39

_______ are positively charged ionic particles.Select one:

a. Transmitters

b. Solvents

c. Anions

d. Electrolytes

e. Cations

Back 39

Cations