The nervous system has three overlapping funcTIons. Which of the following represents a logical sequence of these three funcTIons?
A. Sensory input, motor output, integraTIon
B. Motor output, integration, sensory input
C. Sensory input, integration, motor output
D. Integration, sensory input, motor output
C. Sensory input, integration, motor output
The portion of an axon that communicates with its target cell is the _______.
A. dendrite B. axon C. axon terminal D. cell body
C. axon terminal
A change in membrane potential from -70 mV to -40 mV would be termed __________.
A. repolarization B. depolarization C. hyperpolarization D. hypopolarization
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Generally speaking, opening chloride channels in the postsynaptic membrane will result in an _______.
A. excitatory postsynaptic potential
B. excitatory presynaptic potential
C. inhibitory postsynaptic potential
D. inhibitory presynaptic potential
C. inhibitory postsynaptic potential
__________ has occurred when a neuron is stimulated by more than one terminal.
A. Temporal summation
B. Spatial summation
C. Synaptic delay
D. Synaptic potentiation
B. Spatial summation
Generation of an action potential can be inhibited by all of the following except: ___________.
A. IPSPs B. presynaptic inhibition C. depolarization D. hyperpolarization
C. depolarization
Which type of potential does not decay with distance?
A. Graded potential B. Action potential C. Generator potential D. Both a and b
B. Action potential
The point at which the all-or-none principle of action potential generation is reached is termed the ________.
A. peak B. depolarization point C. threshold D. point of no return
C. threshold
Sodium ion concentration in the cytoplasm of a neuron ________ when its voltage-gated sodium channels open.
A. increases B. decreases C. remains unchanged D. decreases tenfold
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Depolarization of the neuron refers to __________.
A. a reduction in membrane potential
B. an increase in membrane potential
C. an increased negativity of the neuron interior
D. both b and c
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During membrane repolarization, there is a decrease in the membrane permeability to which ion?
A. Potassium B. Sodium C. Calcium D. Both potassium and sodium
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Neurons generally repolarize once the membrane potential reaches approximately +30 mV because __________.
A. voltage-gated sodium channel gates close B. voltage-gated potassium channel gates open C. chemically gated sodium channels open D. voltage-gated calcium channel gates open
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In an organism, action potentials are propagated unidirectionally toward the axon ending because __________.
A. membranes become nonresponsive due to inactive sodium channels after action potential generation
B. action potentials are always propagated in an anterograde fashion regardless of conditions
C. action potentials cannot start anywhere except at the axon hillock
D. of both a and b
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Stronger stimuli are interpreted when the CNS receives ________ action potentials.
A. higher magnitude B. more frequent C. lower magnitude D. more infrequent
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The nodes of Ranvier are found _______.
A. in the CNS only B. on dendrites C. on the neuroglia D. on myelinated axons
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The location at which a neuron interacts with its target cell (another neuron or a muscle cell or other effector cell) is called the __________.
A. synapse B. junc9on C. connec9on D. axoaxonic target
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The presynaptic neuron releases neurotransmitters in response to an influx of _______ ions.
A. sodium B. potassium C. calcium D. sodium and potassium
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Generally speaking, opening chloride channels in the postsynaptic membrane will result in an _______.
A. excitatory postsynaptic potential B. excitatory presynaptic poten9al C. inhibitory postsynaptic potential D. inhibitory presynaptic potential
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__________ has occurred when a neuron is stimulated by more than one terminal.
A. Temporal summation B. Spatial summation C. Synaptic delay D. Synaptic potentiation
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A reflex that results from practice is a(n) ______ reflex.
A. intrinsic B. acquired C. autonomic D. skilled
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Quickly lifting your foot and leg after stepping on a rock is an example of a(n) ________.
A. learned reflex B. intrinsic reflex C. voluntary action D. central program generator
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The receptors for the stretch reflex are the _________.
A. pain receptors B. muscle spindles C. tendon organs D. touch receptors
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