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1

_____ are specialized junctions between neurons.

Nodes of Ranvier
Synapses
Dendrites
Spines

Synapses

2

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

the electron microscope
single-neuron recordings
behavioral observations
PET scans

behavioral observations

3

The circuit from sensory neuron to muscle response is called:

a reflex arc.
a synapse.
flexion.
extension.

a reflex arc.

4

The proper order of a reflex arc is:

motor neuron, sensory neuron, interneuron.
sensory neuron, motor neuron, interneuron.
motor neuron, interneuron, sensory neuron.
sensory neuron, interneuron, motor neuron.

sensory neuron, interneuron, motor neuron.

5

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

Transmission between neurons at synapses is slower than along axons.
The longer an axon, the slower its velocity.
Interneurons have thicker axons than other neurons.
There are greater amounts of myelin involved in the reflex arc.

Transmission between neurons at synapses is slower than along axons.

6

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?

spatial summation
temporal summation
saltatory conduction
synaptic combination

temporal summation

7

A graded depolarization is known as:

EPIP
IPSP
ESPN
EPSP

EPSP

8

Which of the following is TRUE about EPSPs?

It takes two to produce an action potential.
They decay over time and space.
They can be either excitatory or inhibitory.
They occur because potassium gates open.

They decay over time and space.

9

Which of the following is NOT true of EPSPs?

They decay over time.
Their strength decreases with distance.
They operate on an all-or-none principle.
They are depolarizations.

They operate on an all-or-none principle.

10

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

the magnitude of an action potential decreases as it travels along the membrane.
EPSPs occur without sodium ions entering the cell.
action potentials are always hyperpolarizations.
EPSPs are sub threshold events that decay over time and space.

EPSPs are sub threshold events that decay over time and space.

11

Depolarization is to ____ as hyperpolarization is to ____.

excitation; inhibition
inhibition; excitation
increasing the threshold; decreasing the threshold
decreasing the threshold, increasing the threshold

excitation; inhibition

12

What causes an EPSP?

the deactivation of cytoplasmic enzymes
the opening of sodium channels
the opening of potassium channels
inherited paranormal psychic abilities

the opening of sodium channels

13

Spatial summation refers to:

multiple weak stimulations that occur in rapid succession.
a decrease in responsiveness after repeated stimulation.
multiple weak stimulations that occur at the same time.
an increase in the strength of action potentials after repeated stimulation.

multiple weak stimulations that occur at the same time.

14

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

Only spatial summation can produce an action potential.
Spatial summation depends on contributions from more than one sensory neuron.
Temporal summation produces a hyperpolarization instead of a depolarization.
Spatial summation alters the response of more than one postsynaptic cell.

Spatial summation depends on contributions from more than one sensory neuron.

15

What do temporal summation and spatial summation have in common?

Both involve the activity of only two neurons.
Both require a response from the brain.
Both depend on a combination of visual and auditory stimuli.
Both enable a reflex to occur in response to weak stimuli.

Both enable a reflex to occur in response to weak stimuli.

16

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

rapid sequence of EPSPs
rapid sequence of IPSPs
large number of simultaneous IPSPs
large number of simultaneous IPSPs and EPSPs

rapid sequence of EPSPs

17

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

the ligaments and tendons that bind them together
learned patterns of coordination in the cerebral cortex
inhibitory synapses in the spinal cord
control of both muscles by different branches of the same axon

inhibitory synapses in the spinal cord

18

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

glial cells.
motor neurons.
sensory neurons.
interneurons.

interneurons.

19

Inhibitory synapses on a neuron:

hyperpolarize the postsynaptic cell.
weaken the cell's polarization.
increase the probability of an action potential.
move the potential closer to the cell's threshold.

hyperpolarize the postsynaptic cell.

20

A temporary hyperpolarization is known as an:

EPSP
IPSP
ISPS
EPIP

IPSP

21

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

potassium ions entering the cell
sodium ions entering the cell
chloride ions entering the cell
chloride ions leaving the cell

chloride ions entering the cell

22

An EPSP is to ___ as an IPSP is to ____.

hyperpolarization; depolarization
depolarization; hyperpolarization
spatial summation; temporal summation
temporal summation; spatial summation

depolarization; hyperpolarization

23

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

spontaneous firing rate
excitatory firing rate
all-or-none law
Dale's principle

spontaneous firing rate

24

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

spontaneous firing rate
excitatory firing rate
all-or-none law
Dale's principle

spontaneous firing rate

25

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

number of EPSPs only
spontaneous firing rate
number is IPSPs only
ratio of EPSPs to IPSPs

ratio of EPSPs to IPSPs

26

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

EPSPs increase the frequency.
EPSPs decrease the frequency.
IPSPs increase the frequency.
One EPSP equals the effect of two IPSPs.

EPSPs increase the frequency.