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WorksheetsChapter 41 Practice Questions
Total questions: 32
Worksheet time: 16mins
Which of the following would not be classified as a stimulus?
presence of predators
changes in external temperature
lowered blood pressure
hunger
None of the above, all are stimuli
The initial response to a stimulus involves which process?
action
integration
interpretation
reception
transmission
Afferent neurons:
transmit information to the central nervous system
provide support for the neurons
connect motor and sensory neurons
transmit information from the central nervous system to effectors
The myelin sheath:
is a protein covering around dendrites
is responsible for integrating information
is a fatty covering only around axons
stores neurotransmitters in the axon
is a fatty covering only around cell bodies
Which of the following provides insulation for the neuron?
synapse
axon
dendrite
Schwann cell
Node of Ranvier
The structure labeled 3 in the accompanying figure is:
a node of Ranvier
a cell body
a dendrite
a synaptic terminus
an axon
The function of the structure labeled 5 in the accompanying figure is:
insulation
neurotransmitter release
binding neurotransmitters
conduction of an electrical signal
acting as a ligand-gated channel
The function of the structure labeled 6 in the accompanying figure is:
insulation
neurotransmitter release
binding neurotransmitters
conduction of an electrical signal
acting as a ligand-gated channel
The structure in the figure that is specialized to receive stimuli and send signals to the cell body is labeled:
1
3
4
6
7
Gaps in the myelin sheath are referred to as:
synapses
neuroglia
microglia
Schwann cells
Nodes of Ranvier
Maintenance of the resting membrane potential is accomplished by:
saltatory conduction down the axon
an excess of calcium ions outside the myelin sheath
an accumulation of more positive ions outside the neuron than inside
the voltage-gated potassium ion channels
the storage of acetylcholine in the nerve terminal
The membrane potential in neurons is due to:
passive ion channels
ion pumps
chemically activated ion channels
voltage-activated channels
all of the above
Any type of stimulus can alter resting potential by increasing the permeability of the membrane to:
potassium
sodium
calcium
neurotransmitters
enkephalins
A nerve impulse moves along a neuron as:
sodium moves into the cell and potassium moves out of the cell
sodium binds to potassium
sodium and potassium are pulled apart
acetylcholine moves along the nerve fiber
calcium exits the dendrites
The ion flow in part 1 of this figure:
represents the equilibrium potential
represents the resting state
will increase the rate of repolarization
will reestablish the electronegative resting potential
represents the initial response of a neuron to an action potential
Based on part 2 of the accompanying figure, the ions involved in ______ are ___.
depolarization; Cl-
repolarization; K+
depolarization; Na+
repolarization; Cl-
hyperpolarization: Na+
Which of the following statements about the speed of impulse conduction in a neuron is true?
Longer axons can transmit impulses faster than shorter ones
Unmyelinated axons transmit impulses faster than myelinated ones
Shorter axons can transmit impulses faster than longer ones
Nerve impulses travel faster than the speed of light
Axons with larger diameters transmit impulses faster than ones with smaller diameters.
Letter B in the diagram is accomplished by:
an influx of Ca2+
an influx of Na2+
an influx of K+
an efflux of Na2+
an efflux of K+
In the accompanying figure, letter E is:
the resting state
indicative of repolarization
the threshold level
the equilibrium potential
indicative of hyperpolarization
During the relative refractory period:
an axon can transmit impulses comparable to a resting neuron
an axon cannot transmit an action potential at all
an axon can transmit impulses, but the threshold level is higher
all voltage-activated sodium channels are inactivated
neurons can only transmit several impulses per second
Saltatory conduction:
does not involve voltage-activated potassium ion channels
can occur in both myelinated and unmyelinated nuerons
is slightly slower than continuous conduction
is more energy efficient than continuous conduction
allows nerve impulse to jump from Schwann cell to Schwann cell
The all-or-none law states that:
if a stimulus is strong enough, all axons in a nerve bundle will fire simultaneously
a neuron will only produce an action potential if it has been depolarized to its threshold level
all neurons discharge impulses at the same frequency
a neuron can create an action potential of varying intensities
either all or none of the neurons will fire impulses when stimulated
Which type of neuron integrates information coming into and out of the central nervous system?
afferent neurons
motor neurons
interneurons
efferent neurons
sensory neurons
Which of the following statements concerning glial cells is true?
Astrocytes are phagocytic cells that remove debris in the central nervous system.
Schwann cells form sheaths around neurons within the central nervous system.
Microglia are involved in neurological disease, multiple sclerosis.
Oligodendrocytes regulate the concentration of neurotransmitters in neurons.
None of the above
What is the function of neuroglia?
to detect stimuli
to support and protect neurons
to produce hormones
to interpret incoming sensory information
to produce neurotransmitters
Which statement about the structure of neurons is true?
Dendrites carry impulses away from the cell body
Axons may form branches known as collaterals.
nerve impulses travel down the axon toward the cell body.
Dendrites are often myelinated for faster conduction.
Synapses occur between the cell body and its axon.
In a resting neuron:
the concentration of potassium ions is about 10 times greater inside the cell than in the extracellular fluid
excitatory postsynaptic potentials hyperpolarize the membrane
voltage-activated sodium channels are pumping sodium inside the cell against its concentration gradient
the membrane is more permeable to sodium than potassium ions
inhibitory postsynaptic potentials depolarize the membrane
When the membrane potential of a neuron reaches the threshold level:
voltage-gated sodium channels open, and sodium diffuses out of the cell
voltage-gated potassium channels open for a very brief period
voltage-gated sodium channels close, so sodium cannot diffuse out of the cell
the sodium channel protein changes its shape to open the gates of the channel
the membrane potential is more negative than at rest
Since all action potentials are identical, the intensity of a sensation depends on:
whether a myelinated or unmyelinated neuron has been stimulated
the duration of the stimulation
whether the neuron stimulated is a pre- or postsynaptic neuron
the total number of neurons stimulated and the frequency of their discharge
the presence of an EPSP or IPSP which allows for a graded response
An excitatory postsynaptic potential (EPSP):
results in a partial depolarization of the neuron
causes a neuron to fire
prevents a neuron from firing
results in a partial hyperpolarization of the neuron
results in partial depolarization of presynaptic neurons, causing ions to pass through connecting channels
Which of the following charateristics is not true of excitatory postsynaptic potentials and inhibitory postsynaptic potentials?
They may both be summed spatially or temporally
Both EPSPs and IPSPs are graded potentials
IPSPs cancel the effects of some of the EPSPs
Each EPSP or IPSP affects the membrane potential of the neuron
They both represent an all-or-none response
In divergence, one neuron:
is controlled by several neurons
is controlled by several neurotransmitter substances
contains several different types of ion channels
controls several other neurons
contains several different types of receptors
