Chapter 12 Neural Questions
Depolarization of the membrane will shift the membrane potential toward __________. 0 mV -70 mV -85 mV -90 mV
0 mV
Which of the following is a correct statement of the all-or-nothing principle? A hyperpolarized membrane always results in the production of an action potential. Action potentials occur in all neurons if a stimulus is applied that lowers the membrane potential. A given stimulus either triggers a typical action potential or does not produce one at all. When a stimulus is applied, it triggers an action potential in the membrane.
A given stimulus either triggers a typical action potential or does not produce one at all.
What happens when a barrier prevents the movement of opposite charges toward one another? A current is produced. An action potential occurs. A generation potential is produced. A potential difference exists.
A potential difference exists.
Facilitation in the neuron's transmembrane potential toward threshold results from what? exposure to certain drugs, such as nicotine any shift that makes the cell more sensitive to further stimulation summation of EPSPs All of the listed responses are correct.
All of the listed responses are correct.
The reason that active neurons need ATP is to support __________. the synthesis, release, and recycling of neurotransmitter molecules the movement of materials to and from the soma via axoplasmic flow the recovery from action potentials All of the listed responses are correct.
All of the listed responses are correct.
What is included in the primary functions of the nervous system? integrating sensory information providing sensation of the internal and external environments regulating and controlling peripheral structures and systems All of the listed responses are correct.
All of the listed responses are correct.
Emma is very excited because after taking up running several months ago, she has begun to experience the phenomenon called "runner's high." This is caused by the production of endorphins. What is the effect of the endorphins on Emma when she runs? Endorphins cause an increase in the amount of myelin on axons, making impulses travel faster. Endorphins are blocking the transmission of substance P, a neurotransmitter that sends information about pain to the CNS. Endorphins lower the level of threshold at the initial segments of her axons, making it easier for impulses to be transmitted through her body. None of the listed responses is correct.
Endorphins are blocking the transmission of substance P, a neurotransmitter that sends information about pain to the CNS.
Efferent pathways consist of axons that carry impulses __________. toward the CNS to the spinal cord and into the brain away from the CNS from the PNS to the CNS
away from the CNS
The region of a neuron with voltage-gated sodium channels is the __________. soma perikaryon axon dendrite
axon
During the relative refractory period, a larger-than-normal depolarizing stimulus can __________. cause the membrane to hyperpolarize inhibit the production of an action potential bring the membrane to threshold and initiate a second action potential cause a membrane to reject a response to further stimulation
bring the membrane to threshold and initiate a second action potential
nterneurons, or association neurons, differ from sensory and motor neurons in their __________. structural characteristics functional capabilities exclusive location in the brain and spinal cord inability to generate action potentials
exclusive location in the brain and spinal cord
Rachel decides to go swimming, but when she sticks her big toe into the water, she changes her mind because the water is too cold. The sensory neurons responsible for sending the message about the temperature of the cold water are __________. exteroceptors proprioceptors enviroceptors interoceptors
exteroceptors
Saltatory conduction conducts impulses along an axon __________. at a rate determined by the strength of the stimulus five to seven times faster than continuous conduction two to three times more slowly than continuous conduction at a velocity determined by the rate at which the stimulus is applied
five to seven times faster than continuous conduction
Sensory (ascending) pathways distribute information __________. from the central nervous system to the peripheral nervous system from peripheral receptors to processing centers in the brain from processing centers in the brain to peripheral receptors from motor pathways to interneurons in the CNS
from peripheral receptors to processing centers in the brain
Nerve cell bodies in the PNS are clustered together in masses called __________. neuromodulators proprioceptors nodes ganglia
ganglia
At an electrical synapse, the presynaptic and postsynaptic membranes are locked together at __________. gap junctions synaptic vesicles myelinated axons neuromuscular junctions
gap junctions
Which of the following is the most excitatory neurotransmitter in the brain and functions in learning and memory? glutamate dynorphins anamidine norepinephrine
glutamate
An inhibitory postsynaptic potential (IPSP) is a __________. graded hyperpolarization of the postsynaptic membrane reflection of the activation of an opposing transmembrane potential repolarization produced by the addition of multiple stimuli depolarization produced by the effect of a neurotransmitter
graded hyperpolarization of the postsynaptic membrane
What is the term given to describe a shift in transmembrane potential from -70 mV to -90 mV? repolarization hyperpolarization depolarization None of the listed responses is correct.
hyperpolarization
Neurons are responsible for __________. information transfer and processing in the nervous system controlling the interstitial environment creating a three-dimensional framework for the CNS performing repairs in damaged neural tissue
information transfer and processing in the nervous system
What are the two major cell populations of neural tissue? microglia and ependymal cells neurons and neuroglia astrocytes and oligodendrocytes satellite cells and Schwann cells
neurons and neuroglia
If resting membrane potential is -70 mV and the threshold is -60 mV, a membrane potential of -62 mV will __________. repolarize the membrane to −80 mV produce an action potential depolarize the membrane to 0 mV not produce an action potential
not produce an action potential
The white matter of the CNS represents a region dominated by the presence of __________. unmyelinated axons oligodendrocytes astrocytes neuroglia
oligodendrocytes
Graded potentials that develop on the postsynaptic membrane in response to a neurotransmitter are __________. presynaptic facilitators postsynaptic potentials presynaptic potentials presynaptic inhibitors
postsynaptic potentials
Exocytosis and the release of acetylcholine into the synaptic cleft are triggered by __________. reabsorption of calcium into the endoplasmic reticulum active transport of calcium into synaptic vesicles calcium ions flooding into the synaptic terminal calcium ions leaving the cytoplasm
calcium ions flooding into the synaptic terminal
Which part of the nervous system performs the higher-order thinking required to complete this practice exam? afferent division central nervous system autonomic nervous system peripheral nervous system
central nervous system
he main functional difference between the autonomic nervous system and the somatic nervous system is that the activities of the ANS are __________. primarily involuntary, or under "automatic" control involved with carrying impulses to the CNS primarily voluntary controlled involved with affecting skeletal muscle activity
primarily involuntary, or under "automatic" control
Schwann cells are glial cells responsible for __________. surrounding nerve cell bodies in peripheral ganglia producing a neurilemma around peripheral axons secretion of cerebrospinal fluid phagocytic activities in the neural tissue of the PNS
producing a neurilemma around peripheral axons
An important neurotransmitter in emotional states and moods is __________. substance P serotonin acetylcholine aspartate
serotonin
The addition of stimuli occurring in rapid succession at a single synapse is __________. spatial summation the absolute refractory period facilitation temporal summation
temporal summation
Lulu, who is 50 years old, decides she wants to receive Botox treatments. If Botox, short for botulism toxin, prevents the release of ACh from synaptic terminals, what effect should Lulu expect from having Botox injected into her facial muscles? difficulty breathing prolonged muscle contractions in her facial muscles temporary paralysis in the injected facial muscles None of the listed responses is correct.
temporary paralysis in the injected facial muscles
What are the most important factors that determine the rate of action potential conduction? the strength of the stimulus and the rate at which the stimulus is applied the presence or absence of a myelin sheath and the diameter of the axon the number of neurons and the length of their axons All of the listed responses are correct.
the presence or absence of a myelin sheath and the diameter of the axon
A node along the axon represents an area where __________. there is an absence of myelin there is a gap in the cell membrane there is a layer of fat there are interwoven layers of myelin and protien
there is an absence of myelin
Sensory neurons are responsible for carrying impulses __________. away from the CNS from the CNS to the PNS to the PNS to the CNS
to the CNS
n type C fibers, action potentials are conducted at speeds of approximately __________. 2 mph 40 mph 150 mph 500 mph
2 mph
Ann and Elise are two college students on an overseas vacation. Because they both love seafood, they stop at a restaurant in a coastal town for lunch. After dining on shellfish, they become very sick and have trouble breathing. What may have happened to Ann and Elise? They may have consumed ciguatoxin (CTX), which can interfere with muscle control. They may have consumed saxitoxin (STX), which blocks sodium ion channels. They may have consumed some tetrodotoxin (TTX), which can cause abnormal sensations. Any of the responses could be correct. TTX, STX, and CTX all block sodium ion channels, cause abnormal sensations, and interfere with muscle control.
Any of the responses could be correct. TTX, STX, and CTX all block sodium ion channels, cause abnormal sensations, and interfere with muscle control.
Which of the following statements about repolarization of an axon is FALSE? During repolarization, the axon will be in a refractory period. Repolarization follows depolarization of the axon. Repolarization is marked by the movement of potassium ions out of the cell membrane. Repolarization occurs when sodium ion channels are open.
Repolarization occurs when sodium ion channels are open.
Tyson decides to travel overseas but does not have all the required vaccines needed before he goes. While on his trip, he contracts diphtheria. Which type of glial cell is particularly at risk from this disease? Schwann cells oligodendrocytes microglia satellite cells
Schwann cells
Which of the following statements about the sodium-potassium pump is correct? The sodium-potassium pump brings sodium into a neuron during depolarization and forces potassium out of a neuron during depolarization. The activity of the sodium-potassium pump is needed after every action potential to restore resting potential. The sodium-potassium pump is a leak channel that allows passive movement of sodium and potassium ions down the concentration gradient. The sodium-potassium pump requires ATP to pump sodium and potassium ions from higher to lower concentrations along their concentration gradients.
The activity of the sodium-potassium pump is needed after every action potential to restore resting potential.
Which of the following is true of axons? The size of the axon does not affect the rate of transmission or resistance. The larger the diameter of the axon, the slower the rate of transmission. The larger the diameter of the axon, the greater the resistance. The larger the diameter of the axon, the faster the rate of transmission.
The larger the diameter of the axon, the faster the rate of transmission.
What happens when depolarization to threshold occurs? Leak channels are activated. Sodium channels are inactivated. Voltage-gated potassium channels open. Voltage-gated sodium channels are opened.
Voltage-gated sodium channels are opened.
An excitatory postsynaptic potential (EPSP) is __________. a graded depolarization produced by the arrival of a neurotransmitter an action potential complying with the all-or-none principle the same as a nerve impulse along an axon a result of a stimulus strong enough to produce threshold
a graded depolarization produced by the arrival of a neurotransmitter
At the site of an action potential, the membrane contains __________. an excess of positive ions inside and an excess of negative ions outside an equal number of positive and negative ions on either side of the membrane an excess of negative ions inside and an excess of negative ions outside an equal number of positive ions on either side of the membrane
an excess of positive ions inside and an excess of negative ions outside
Which of the following structures is NOT part of the PNS? a ganglion a sensory receptor an interneuron within an autonomic ganglion an interneuron within the spinal cord
an interneuron within the spinal cord
Interneurons are responsible for __________. analysis of sensory inputs and coordination of motor outputs collecting information from the external or internal environment carrying instructions from the CNS to peripheral effectors delivery of information to the CNS
analysis of sensory inputs and coordination of motor outputs
Rabies is a viral disease contracted from the bite of an infected animal. Rabies bypasses many immune system defenses by traveling in peripheral neurons to reach the CNS. Which method of transport is NOT used by the rabies virus to reach the CNS? osmosis retrograde flow anterograde flow axoplasmic transport
anterograde flow
What type of gated channel opens or closes in response to distortion of the membrane? voltage-gated channel leak channel mechanically gated channel chemically gated channel
mechanically gated channel
Which of the following CNS glial cells remove debris, wastes, and pathogens by phagocytosis? astrocytes Schwann cells microglia ependymal cells
microglia
Neurons are classified on the basis of their function as __________. motor, sensory, or association somatic, visceral, or autonomic unipolar, bipolar, or multipolar central, peripheral, or somatic
motor, sensory, or association
Neurons are classified on the basis of their structure as __________. anaxonic, unipolar, bipolar, or multipolar astrocytes, oligodendrocytes, microglia, or ependymal efferent, afferent, association, or interneurons motor, sensory, association, or interneurons
motor, sensory, or association
