What is a typical neuron composed of?
A soma, an axon, and one or more dendrites
Which way to dendrites typically carry info?
Toward the soma
What is the input center of a neuron?
Dendrites
What is the integration center of a neuron?
Axon hillock
What is the conduction center of a neuron?
Axon
What is the output center of a neuron?
Presynaptic terminals
What is the maintenance center of a neuron?
The soma
What does the axon hillock do?
Determines what info is conducted down the axon
Do action potentials decrease in size while they go down the axon?
No they stay constant
What is kinesin?
Drags new membrane down the axon away from soma
What direction does kinesin bring material?
Anterograde
What is dynein?
Drags old membrane down the axon toward soma
What direction does dynein bring material?
Retrograde
T/F:
At equilibrium the diffusional flux of an ion is equivalent to the unidirectional flux due to membrane voltage?
True
Which way does the membrane potential go when channel is open?
Toward the equilibrium potential
Which way does the membrane potential go when channel is closed?
Away from the equilibrium potential
What is the equation for equilibrium potentials called?
Nernst equation
What is the equilibrium potential equation?
E=60/charge*log([out]/[in])
At rest what is channels are open?
Some K+ channels
What is the average resting potential of the membrane?
-70mV
Changes that make the membrane potential more negative?
Hyperpolarization
Changes that make the membrane potential less positive?
Depolarization
Do graded potentials decrease in strength as they spread across the membrane?
Yes
What cause action potentials?
Depolarizing grades potentials
Are action potentials variable or all or nothing?
All or nothing
Do actions potentials have a threshold?
Yes
What is the absolute refractory period?
The time after a spike where another AP can’t occur
What is the relative refractory period?
The time where AP occurs at a higher threshold
When are voltage gated Na+ channels activated?
Depolarization
Are Na+ voltage channels slow or fast?
Fast
Do Na+ channels cause depolarization or hyperpolarization?
Depolarization
What causes the inactivation gate to close?
Depolarization
Why does the inactivation gate not close automatically?
It is slow
What does the inactivation gate closing allow?
The cell to repolarize
What opens voltage gated K+ channels?
Depolarization
Are voltage gated K+ channels activated fast or slow?
Slow
Why are voltage gated K+ channels activated slow?
Because the gate on them is slow
What do open voltage gated K+ channels cause?
Repolarization and hyperpolarization
Do voltage gated K+ channels inactivate?
No
Why do voltage gated K+ channels not inactivate?
Because they close when the membrane potential comes back to threshold
What are ways to make the action potential travel faster?
Large diameter and myelin
What do myelinated axons have?
Nodes of Ranvier
What is the action potential jumping from node to node called?
Saltatory conduction
What are located in the nodes of Ranvier?
Voltage gated Na+ and K+ channels
What is the amount of NT released known as?
The quantum
How does Ca++ enter a presynaptic terminal?
Voltage gated Ca++ channels
How does Ca++ leave the presynpatic terminal?
Ca++-ATPase
What do you call a voltage change that causes the cell to be more likely to fire an AP or release more NT?
Excitatory post synaptic potential (EPSP)
What do you call a voltage change that causes the cell to be less likely to fire an AP or release less NT?
Inhibitory post synaptic potential (IPSP)
What are receptors for acetylcholine?
Cholinergic receptors
What are receptors for norepinephrine and epinephrine?
Adrenergic
What are the types of cholinergic receptors?
Nicotinic and muscarinic
What are the types of adrenergic receptors?
Alpha-adrenergic and beta-adrenergic
What are nicotinic receptors?
Ion channels
What are muscarinic receptors?
Linked to Gi and Gp proteins
What are alpha-adrenergic receptors?
Linked to Gi or Gp proteins
What are beta-adrenergic receptors?
Linked to Gs protein
What ions cause EPSPs?
Na+ and Ca++
What ions cause IPSPs?
K+ and Cl-
What is temporal summation?
Summation of PSP that arrive at different times
What is spatial summation?
Summation of PSP that arrive ate different synapses
What does amplitude coding represent?
The summation of the various PSPs
What type of synapses are in parasmpathetic pre and post ganglionic fibers?
Cholinergic
What type of synapses are in sympathertic pre and post ganglionic fibers?
Pre = cholinergic Post = adrenergic
What type of synapses are in simatic motor nerves?
Cholinergic synapses
What is amplitude coding?
Size of the stimuli
What is frequency coding?
How often the stimuli occurs?
What is labeled line coding?
You know where the stimuli came from so you know what it is
What is another name for population coding?
Constellation coding
What is population coding?
Make a determination about what is going on based on several stimuli
What is antagonistic control?
Control both stimuli (brake and gas)
What is tonic control?
Control one of the stimuli
What is lag time?
How long it takes for a response
What is feed forward?
You know you are eating soon so start preparing
What is sensitivity?
How easily does a stimuli trigger a response
What is gain?
What the response does to fix imbalance
What is positive feedback?
Feedback that causes more of the same stimuli to occur
Hydrophobic product of phosphatidyl inositol-bis-phosphate?
Diacylglycerol
Hydrophillic product of phosphatidyl inositol-bis-phosphate
Inositol triphosphate
Structures between cells in transporting epithelia?
Tight junctions