Term
Where do action potentials propagate? |
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Definition
along the membrane of the conductile region of a neuron |
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Term
What is the conductile region? |
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Definition
it carries electrical information long distances. It also contains voltage-gated Na+ and K+ channels which are responsible for an action potential |
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Term
What is the Neuron Doctrine? |
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Definition
says that a neuron is a functional unit of the nervous system |
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Term
What is sensory transduction, and what are the 3 forms? |
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Definition
It is changing the form of energy (conversion to movement of ions across a membrane). Three forms: Electromagnetic, chemical, mechanical. |
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Term
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Definition
Kinesin is a motor protein that transports vesicles along microtubles. + end directed, cleaves ATD to ADP |
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Term
What kind of glial cells are in the central nervous system? |
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Definition
Astrocytes, oligodendrocytes, microglia |
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Term
What type of glial cell is in the Peripheral nervous system? |
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Definition
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Term
Myelinating glial cells provide: |
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Definition
provide insulation and physically surround neurons |
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Term
Afferent nerves carry information |
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Definition
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Term
Efferent nerves carry information |
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Definition
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Term
Afferent nerves carry information |
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Definition
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Term
Efferent nerves carry information |
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Definition
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Term
Potentials propagating away from the central nervous system carry |
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Definition
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Term
Mechanisms for removing neurotransmitter from synaptic cleft include |
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Definition
absorbed by astrocyte, diffuse away, degraded by enzymes |
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Term
What depolarizes a membrane? |
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Definition
voltage-gated sodium channels |
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Term
what is the equilibrium potential of sodium? |
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Definition
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Term
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Definition
the membrane potential where rate of sodium influx through v-gated channels equals the rate of K+ efflux through leak channels |
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Term
What is the equilibrium potential of potassium? |
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Definition
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Term
What is the concept of ball and chain? |
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Definition
as soon as the voltage-gated sodium channels open, they also start to inactivate. this limits membrane Na+ permeability |
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Term
What happens at the top of the action potential? |
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Definition
Na+ channels inactivate, K+ leak channels are still open, voltage-gated K+ channels are ALL open by the time Na+ channels inactivate |
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Term
What happens when voltage-gated potassium channels open during an action potential? |
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Definition
It starts to repolarize the membrane bringing the membrane potential close to the equilibrium potential of potassium. with the help of flickering Na+ channels, and K+ leak channels it will restore to resting membrane potential |
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Term
Where are voltage-gated Na+ and voltage-gated K+ channels located? |
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Definition
between the nodes on the axon |
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Term
What is the voltage at the resting membrane potential? |
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Definition
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Term
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Definition
bundles of nerve cells in PNS |
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Term
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Definition
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Term
What is a somatic afferent? |
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Definition
neuron that brings info about skin, skeletal muscles, and joints to the CNS |
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Term
What is a visceral afferent? |
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Definition
a neuron that brings in information to CNS about organs |
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Term
What are the two motor divisions of PNS? |
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Definition
Somatic Nervous system, and autonomic nervous system |
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Term
What nervous system does the parasympathetic and sympathetic branches belong to? |
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Definition
part of the autonomic nervous system which is a portion of the PNS |
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Term
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Definition
collection of cell bodies and unmyelinated proceses (divided into the dorsal and ventral horns) |
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Term
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Definition
myelinated axons (white because of large amounts of lipids) |
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Term
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Definition
cell bodies and dendrites of interneurons that are important for afferent info from PNS to CNS |
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Term
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Definition
cell bodies and dendrites of lower motor neurons |
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Term
Where do lower motor neurons exit the CNS? |
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Definition
through the ventral roots |
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Term
Afferent neurons enter on the ( ) side, and makes its way to the ( ) side. |
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Definition
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Term
Efferent neurons enter the ( ) side, and move to the ( ) side. |
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Definition
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Term
Dendrites are the ( ) region of the cell. |
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Definition
input region, NEVER myelinated, conduct graded potentials |
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Term
What is the trigger zone? |
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Definition
site of action potential initiation |
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Term
Interneurons are confined to... |
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Definition
the central nervous system |
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Term
what is the function of an astrocyte? |
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Definition
it helps regulate ion concentration in the extracellular environment (mostly K+), also regulates neurotransmitter concentration at synapse, positioned around capillaries. |
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Term
What is the function of an oligodendrocyte? |
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Definition
myelinating axons, and forming white matter in CNS, they can wrap around multiple axons, inhibit regeneration in CNS |
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Term
What is the function of a schwann cell? |
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Definition
to myelinate axons, only one axon at a time, cleans up debris after nerve damage in peripheral, regenerate nerves |
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Term
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Definition
in the cell body, and dendrites only |
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Term
Microtubules are composed of |
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Definition
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Term
When do stretch activated channels open? |
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Definition
when we tug on the membrane it opens the channel, the change in membrane brings in sodium. # of stretch activated channels is proportion to the amount of stretch. |
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Term
Voltage-gated Na+ channels are triggered by ( ), unlike Na+ stretch activated channels which are triggered by ( ). |
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Definition
V-gated activated by charge, stretch activated by stretch in membrane |
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Term
Cell bodies of preganglionic sympathetic neurons are located in... |
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Definition
the intermediolateral gray column of spinal cord |
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Term
Where do preganglionic sympathetic neurons exit? |
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Definition
exit the spinal cord in the ventral root and synapse on post ganglionic sympathetic neurons |
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Term
Where do cell bodies of somatic afferents reside? |
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Definition
in the dorsal root ganglia |
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Term
Where would protein synthesis take place for a lower motor neuron? |
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Definition
in the ventral horn of the spinal cord |
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Term
By severing a nerve, one would cut.. |
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Definition
the conductile processes in the PNS (because nerve is a term used in the peripheral nervous system, not central.) |
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Term
What does fast axoplasmic transport move? |
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Definition
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Term
What does slow axoplasmic transport move? |
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Definition
moves actin, tubulin, and neurofilaments |
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Term
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Definition
bundles of conductile regions in the CNS |
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Term
Where are voltage-gated Ca+ channels for NT release synthesized? |
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Definition
synthesized in the cell body in the rough ER |
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Term
Input regions from post synaptic cells at chemical synapses contain what kind of channels? |
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Definition
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Term
An EPSP (excitatory post synaptic potential) results from: |
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Definition
the opening of ligand-gated channels |
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Term
What dictates the postsynaptic response at chemical synapses? |
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Definition
the receptor that binds the NT |
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Term
the synapse between postganglionic parasympathetic neurons requires what kind of receptors? |
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Definition
muscarinic and metabrotropic acetycholine receptors |
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Term
Huntington's Disease which is associated with the uncontrolled generation of movement results from: |
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Definition
damage to the neurons in the striatum |
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Term
What does adenylyl cyclase do? |
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Definition
it converts ATP to cyclic AMP |
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Term
Cutting the vagus nerve would cut.. |
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Definition
the conductile regions of preganglionic parasympathetic neurons |
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Term
Visceral efferents innervate |
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Definition
glands, cardiac muscle, and smooth muscle |
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Term
somatic efferents innervate |
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Definition
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Term
In skeletal muscle contraction Calcium leaves SR through what type of receptors? |
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Definition
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Term
How does calcium reenter the SR? |
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Definition
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Term
What does calcium bind to after leaving the SR? |
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Definition
troponin to move tropomyosin |
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Term
When does a power stroke occur in muscle contraction? |
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Definition
when ADP and P leaves myosin |
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Term
Myosin releases its hold on actin when... |
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Definition
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Term
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Definition
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Term
a motor unit is composed of |
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Definition
a lower motor neuron and all the cells it innervates |
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Term
what is spatial summation? |
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Definition
when EPSP's come together from different places |
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Term
What is temporal summation? |
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Definition
when EPSP's come together at the same time |
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Term
Where are the cell bodies located for a neuron whose output region is in the left ventral horn? |
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Definition
on the right precentral gyrus |
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Term
Where are EPSPs initiated? |
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Definition
in the input region of the postsynaptic cell |
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Term
What causes neurotransmitter to be released from the presynapse? |
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Definition
the opening of voltage gated calcium channel causes exocytosis of synaptic vesicle to synaptic cleft releasing neurotransmitter. |
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Term
What happens when action potential arrives to presynaptic element? |
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Definition
it delivers positive charge, allowing calcium to flow in through voltage-gated calcium channels |
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Term
What happens when neurotransmitter leaves the presynaptic element? |
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Definition
it binds to ligand-gated channels opening the gates for sodium to flow into post synaptic element |
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Term
What happens when sodium flows into the post-synaptic element? |
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Definition
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Term
What happens after the sodium ions move into post synaptic element? |
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Definition
it depolarizes membrane and then releases neurotransmitters from the ligand-gated channels |
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