Term
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Definition
| Neuron either generates an AP or it does not |
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Term
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Definition
Insulates the current so it stays directed in the neuron
Makes conduction 50x faster
Thicker fiber--> Faster conduction |
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Term
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Definition
| Rapid, transient changes in membrane potential |
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Term
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Definition
| Resting Membrane Potential |
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Term
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Definition
| A separation of opposite charges |
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Term
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Definition
Membrane potential is reduced-moving more + inside
Excitatory |
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Term
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Definition
| Membrane returns to RMP after depolarization |
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Term
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Definition
Potential is greater than RMP
More negative than -70mVo |
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Term
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Definition
Short-lived
Decrease strength further that they have to travel
decremental (short distance communication) |
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Term
| localized changes in membrane potential |
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Definition
varying grades or degrees of magnitude
multiple sizes |
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Term
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Definition
only cells with "excitable membranes"
(Neurons; Muscle cells)
Brief, rapid reversals of membrane potential
Spread by local current flow
nondecrimental (long distance communication; does not lose power as it travels) |
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Term
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Definition
(long distance communication; does not lose power as it travels)
Action Potential |
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Term
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Definition
Short distance communication
Decreases in strength the further it moves from the initial active site |
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Term
| How fast do changes occur in membrane potential during an action potential |
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Definition
| .003 seconds- 3milliseconds |
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Term
| What happens in the membrane potential during an action potential |
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Definition
Change in membrane permeability
Concentration ions on inside & Outside change |
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Term
| Membrane potential at rest |
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Definition
1 Na in--> Na channels are closed
-70 K out--> K channels are open |
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Term
| Membrane potential during an action potential |
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Definition
Na ions enter into the cell
Threshold- -50 to ~-55 mVs
Na channels open--> +30 mVs
When Na channels close, K channels open, and K moves out of cell (efflux)
cell has -70 mVs charge once again |
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Term
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Definition
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Term
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Definition
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Term
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Definition
Closed, but able to open with stimulation from a stimulus
Open- "activated" -working
Closed, and unable to open -"inactivated"- stimulus cannot open |
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Term
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Definition
| Closed sodium channels that cannot open even if a stimulus is applied |
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Term
| Permeability changes and ion movement during an AP at rest |
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Definition
Polarization
membrane potential: -70 mVs (inside more negative than outside)
State of Na channels: Closed but can open if stimulus comes
Ion permeability: K channels open (1 set) |
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Term
| Permeability changes and ion movement during an AP |
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Definition
Depolarization
Membrane potential- Moving from -70 to more positive reading when a stimulated by a stimulated
State of Na channels:
opened a few channels
-50 to -55 threshold is reached
Trigger Na channels to open
Na ion levels 600x > than K ion levels |
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Term
| Permeability changes and ion movement during an AP at peak |
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Definition
Membrane potential: +30mVs
State of Na+ Channels: Closed and unable to open with a stimulus
Ion permeability- K+ channels open |
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Term
| Permeability changes and ion movement during an AP during the falling phase |
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Definition
Repolarization
membrane potential: from +30mVs down to -70 mVs
State of Na channels- closed an unable to open
Voltage gated K channels: Open, K moves out (efflux)
Ion permeability- K moves out, no Na move |
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Term
| Role of the Na/K-ATPase pump |
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Definition
Move Na+ back out of cell
Move K+ back into cell |
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Term
| Pathway of neuron conduction |
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Definition
Gather info from dendrites
Soma
Axon hillock
Threshhold
ATP |
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Term
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Definition
Ion channels close and lock
Repolarize until RMP is to -70mVs then are able to open again |
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Term
| Signal changes at a neural synapse |
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Definition
| Electrical-->Chemical--> Electrical |
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Term
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Definition
Depolarization
Na channels open
More Na in--> more positive |
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Term
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Definition
Hyperpolarization
Increase in permeability to K+ or Cl-
K+ moves out of cell
Cell becomes more negative |
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Term
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Definition
Excitatory post-synaptic potentials
Na+ influx |
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Term
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Definition
Inhibitory post-synaptic potentials
Cl- influx |
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Term
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Definition
Grand post-synaptic potential
EPSP+IPSP |
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Term
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Definition
characteristic of skeletal muscle is its ability to contract to varying degrees
More than a twitch |
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Term
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Definition
Summation over time
(frequency) |
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Term
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Definition
Summation over space
(multiple neurons fired)
Converging into many cells |
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Term
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Definition
| Single cell is influenced by thousands of other cells |
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Term
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Definition
| Branching at axon terminals into telodendria of other cells to cause one message to go to other cells |
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Term
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Definition
Acetylcholine
Somatic motor neurons (excitatory) |
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Term
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Definition
| Cardiac, smooth muscle, glands receptors |
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Term
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Definition
Receptors for
Brain
Autonomic Ganglia
Skeletal Muscle |
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Term
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Definition
Only ions
Nicotinic receptors
5 polypeptide subunits
Form channel that is chemically gated |
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Term
| G-protein operated channel |
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Definition
Muscarinic Receptors
Only ions pass through
Alpha-beta-gamma complex -one of them activates channel to open |
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Term
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Definition
acetylcholinesterase
Protein on postsynaptic membrane that works as an enzyme- reacts to breakdown neurontransmitter |
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Term
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Definition
Neurotransmitters
Ex.) Serotonin & Dopamine |
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Term
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Definition
Neurotransmitters
In Medulla & Pons
Regulates mood and behavior
Drugs: Prozac, Zoloft, Paxil- antidepressants (keep serotonin in synaptic cleft longer) |
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Term
| Dopamine, Epinephrine, norepinephrine |
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Definition
In midbrain and basal nuclei
Limbic system
Motor control
Emotion/reward system
"Parkinson's" |
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Term
| How are monoamines inactivated? |
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Definition
| Inactivated by breaking down and re-uptake |
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Term
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Definition
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Term
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Definition
Everything but brain and spinal cord
Peripheral Nervous System |
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Term
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Definition
Central Nervous System
Brain and Spinal Cord |
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Term
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Definition
Form myelin sheath in PNS (Grey matter)
Increase rate of conduction by 50x |
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Term
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Definition
| Supports cells for Unipolar |
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Term
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Definition
Myelin sheath in CNS (White Matter)
Increase conduction |
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Term
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Definition
| Phagocytosis- "Pac Man" digest bad/degenerating cells |
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Term
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Definition
Choroid Process--> Choroid Plexus
epithelial membrane lining the ventricular system of the brain and the spinal cord
Involved in production of cerebrospinal fluid (CSF). |
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Term
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Definition
Produce Cerebral Spinal Fluid (CSF)
Most abundant neuroglial cells
Circulate CSF with cilia |
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Term
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Definition
Blood Brain Barrier
Prevents brain from getting bad things from blood Ex.)Viruses |
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