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70 Cards in this Set
- Front
- Back
What is the general function of the nervous system?
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1.detect changes internal and external environments.
2.evaluate the information. 3.initiate an appropriate response. |
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What makes up the central nervous system? (CNS)
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The brain and spinal cord.
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What makes up the peripheral nervous system? (PNS)
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The cranial and spinal nerves.
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Sensory (afferent) neurons is...
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Bring impulses from the peripheral TO the CNS.
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The motor (efferent) neurons...
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Bring impulses from the CNS to the periphery.
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Interneurons (association neurons) lie where?
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Sensory and motor neurons
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The sensory (afferent) Division...
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Conveys impulses to the CNS
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Motor (efferent) Division...
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Conveys impulses FROM the CNS
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Efferent division includes which system?
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The voluntary system; skeletal muscles
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The autonomic system includes...
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Involuntary system; controls the smooth and cardiac muscle glands
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Neurons have...
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Cell bodies, cytoplasmic processes called axons and dendrites
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Axons...
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Generate and conduct nerve impulses away from cell body
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A bundle of nerves is called...
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1.A tract in the CNS
2.a nerve in the PNS |
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A collection of cell bodies is called...
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1.Nucleus in the CNS
2.ganglion in the PNS |
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What are neuroglia?
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Supporting cells which assist neurons in various ways
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What does the CNS neuroglia include?
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1.Astrocytes
2.microgila 3.ependymal cells 4.oligodendrocytes |
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PNS neuroglia include...
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1.Schwann cells
2.satellite cells |
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What do myelin sheath do?
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Insulates and prevents "short-circulating" ; they are formed in PNS by Schwann cells and in the CNS by oligodendrocytes
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What is the gaps b/w the myelin sheath called?
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Nodes of Ranvier; allows faster impulse transmission
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Unmyelinated fibers course "through" what?
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Supporting cells, but their membrane is not wrapped
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Neurons generate two types of signals, what are they?
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Graded and action potentials
(neuron impulses) |
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Graded potentials are...
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Variable in intensity and decrease in strength w/ distance; occur in dendrites and cell bodies
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What an initiate actin potential?
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A strong grades potentials
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Actin potentials are...
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Not variable in intensity and do not decrease in strength w/ distance; happen in a all-or-nothing manner; they happen in an axon
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The resting membrane potential is at and why
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-70 mV; this happens because it has a higher concentration of Na outside membrane and higher concentration of K inside the membrane
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Unmyelinated fibers course "through" what?
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Supporting cells, but their membrane is not wrapped
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Neurons generate two types of signals, what are they?
|
Graded and action potentials
(neuron impulses) |
|
Graded potentials are...
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Variable in intensity and decrease in strength w/ distance; occur in dendrites and cell bodies
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What an initiate actin potential?
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A strong grades potentials
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Actin potentials are...
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Not variable in intensity and do not decrease in strength w/ distance; happen in a all-or-nothing manner; they happen in an axon
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The resting membrane potential is at and why
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-70 mV; this happens because it has a higher concentration of Na outside membrane and higher concentration of K inside the membrane
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Gradient is actively maintained by...
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The cell by their Na/K pumps in their membrane
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Unmyelinated fibers course "through" what?
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Supporting cells, but their membrane is not wrapped
|
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Neurons generate two types of signals, what are they?
|
Graded and action potentials
(neuron impulses) |
|
Graded potentials are...
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Variable in intensity and decrease in strength w/ distance; occur in dendrites and cell bodies
|
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What an initiate actin potential?
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A strong grades potentials
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Actin potentials are...
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Not variable in intensity and do not decrease in strength w/ distance; happen in a all-or-nothing manner; they happen in an axon
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The resting membrane potential is at and why
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-70 mV; this happens because it has a higher concentration of Na outside membrane and higher concentration of K inside the membrane
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Gradient is actively maintained by...
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The cell by their Na/K pumps in their membrane
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Each neuron signals consists of ion movement through channels change what?
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Changes the polarity across the membrane
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Unmyelinated fibers course "through" what?
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Supporting cells, but their membrane is not wrapped
|
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Neurons generate two types of signals, what are they?
|
Graded and action potentials
(neuron impulses) |
|
Graded potentials are...
|
Variable in intensity and decrease in strength w/ distance; occur in dendrites and cell bodies
|
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What an initiate actin potential?
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A strong grades potentials
|
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Actin potentials are...
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Not variable in intensity and do not decrease in strength w/ distance; happen in a all-or-nothing manner; they happen in an axon
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The resting membrane potential is at and why
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-70 mV; this happens because it has a higher concentration of Na outside membrane and higher concentration of K inside the membrane
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Gradient is actively maintained by...
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The cell by their Na/K pumps in their membrane
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Each neuron signals consists of ion movement through channels change what?
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Changes the polarity across the membrane
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Neuron signals are generated by...
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Chemically gated channels and voltage gated channels
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Voltage gates open when...
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They respond to change from the polarity; exist beyond the axon hillock
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Voltage gates open when...
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They respond to change from the polarity; exist beyond the axon hillock
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What is the axon hillock?
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"On switch; generates an impulse emanating from that neuron.
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Voltage gates open when...
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They respond to change from the polarity; exist beyond the axon hillock
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What is the axon hillock?
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"On switch; generates an impulse emanating from that neuron.
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The axon hillock needs to have what in order to open the gate?
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It needs to have experience voltage beyond threshold
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The actin potential passed along a...
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PNS myelinated axon at the nodes of Ranvier (salutatory conduction)
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The actin potential passed along a...
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PNS myelinated axon at the nodes of Ranvier (salutatory conduction)
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Conduction velocities are different because...
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1.Diameter of the axon
2.degree of myelination |
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What are presynaptic neurons?
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Neurons that conduct impulses toward the synapse
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What are presynaptic neurons?
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Neurons that conduct impulses TOWARD the synapse
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What is the post synaptic neurons?
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Neurons that conduct impulses away FROM the synapse
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What is a synaptic delay?
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Time delay at the synapse because of its events and rate-limiting step of impulse transmission
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Two examples of postsynaptic potentials are...
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Excitatory and inhibitory
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Two examples of postsynaptic potentials are...
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Excitatory and inhibitory
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Excitatory postsynaptic potentials...
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Depolarize the postsynaptic membrane to various degrees; allowing positive ions in; initiates an impulse in the postsynaptic neuron
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Two examples of postsynaptic potentials are...
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Excitatory and inhibitory
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Excitatory postsynaptic potentials...
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Depolarize the postsynaptic membrane to various degrees; allowing positive ions in; initiates an impulse in the postsynaptic neuron
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Inhibitory postsynaptic potentials...
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Hyperpolarize the postsynaptic membrane to various degrees; allowing positive ions to leave or negative ions to enter; inhibit an impulse from developing in the postsynaptic neuron
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Summation is...
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The opposing of the two types of postsynaptic neuron will determine if the neuron will generate an impulse at the axon hillock by passing the threshold
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Summation is effected by...
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1.Time-when there is a quick succession if impulses at one synapse delivering one type
2.space-when there are more synapses delivering one type |