Final - Exam (9/13,9/15) - [Exam 1 - Section 2] Flashcards
-Action Potentials -
Recovery:
Ions drift away and are pumped away by Na+ K+ pump
- ___ Na+ out / ___ K+ in
- 3
- 2
-Action Potentials-
Recovery:
Ions drift away and are pumped away by Na+ K+ pump
- 3 ___ out / 2 ___ in
- Na+
- K+
-Action Potentials-
Once an action potential is produced it is always the same _________ (all-or-none law)
size
-Action Potentials-
As action potential travels down the neuron it stays the same size – can be _________ over long distances
conducted
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-Action Potentials-
Refractory periods:
_________ – Na+ channels are open or cannot re-open so neuron cannot fire
Limits how frequently the neuron can fire
Absolute
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-Action Potentials-
Refractory periods:
Absolute – Na+ channels are open or cannot re-open so neuron _________ fire
Limits how _________ the neuron can fire
- cannot
- frequently
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-Action Potentials-
Refractory periods:
_________ – only a strong stimulus can make the neuron fire because NA+ channels are re-setting and neuron is hyperpolarized
Relative
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-Action Potentials-
Refractory periods:
Relative – only a strong stimulus can make the neuron fire because ____ channels are re-setting and neuron is _________
- NA+
- hyperpolarized
-Saltatory Conduction -
Glial cells produce _________ which wrap around axons
myelin sheaths
-Saltatory Conduction-
Ion gates at intervals (1 mm) down the length of the axon - _________
NODES OF RANVIER
-Saltatory Conduction-
The speed at which the action potential travels down a myelinated neuron is _________ than unmyelinated neurons because the action potential jumps from _________ – SALTATORY conduction
- faster
- node to node
The speed at which the action potential travels down a myelinated neuron is faster than unmyelinated neurons because the action potential jumps from node to node – _________
SALTATORY conduction
Deterioration of the myelin sheath - _________
multiple sclerosis
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-Toxins and Anesthetics -
Various toxins block the Na+ K+ pump or the ion channels preventing neurons from firing
-Puffer (fugu) fish toxin blocks ___ channels
Tetrodotoxin (TTX)
-Na+
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-Toxins and Anesthetics-
Scorpion venom keeps ___ channels open and closes ___ channels
-Prolonged depolarization
- Na+
- K+
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-Toxins and Anesthetics-
Various toxins block the Na+ K+ _________ or the ion channels preventing neurons from firing
-Poison arrow frogs produce Na+ channel blocker that keeps Na+ channels _________
- pump
- open
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-Toxins and Anesthetics-
Local anesthetics block _________ channels
-blocks action potentials so no _________ messages reach the brain
- sodium
- pain
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-Toxins and Anesthetics-
General anesthetics act by opening _________ channels
Potassium (K+)
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-Toxins and Anesthetics-
Mutations in ion channels (_________ ) associated with seizure disorders, deafness, muscle and cardiac diseases
channelopathy
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-Toxins and Anesthetics-
Mutations in ion channels (channelopathy) associated with seizure disorders, _________, muscle and _________ diseases
- deafness
- cardiac
There is a small gap (less than a millionth of an inch) between the terminal branches of the neuronal axon and the dendrites of the next neuron - _________
SYNAPTIC CLEFT
There is a small gap (less than a millionth of an inch) between the _________ of the neuronal axon and the _________ of the next neuron - SYNAPTIC CLEFT
- terminal branches
- dendrites
The neuron that sends the signal is called the _________ neuron
presynaptic
The neuron receiving the signal is called the _________ neuron
postsynaptic
An action potential in a neuron causes release of chemicals called _________ from the axon terminals into the synaptic cleft
-exocytosis
NEUROTRANSMITTERS
An action potential in a neuron causes release of chemicals called NEUROTRANSMITTERS from the axon terminals into the synaptic cleft
- _________
exocytosis
Neurotransmitters are formed in the cell body or axon terminals and packaged in _________
vesicles
Neurotransmitters are formed in the _________ or axon terminals and packaged in vesicles
cell body
NEUROTRANSMITTERS bind to _________ on the dendrites of the next neuron
RECEPTORS