Insane in the membrane
The membrane can be describes as this
A Capacitor
This serves as the overall purpose of the action potential
To Transmit information over a Long Distance through out the neuron to the synaptic terminal
These channels allow for passive movement of ions
Leakage channels
This formula describes the storing and separating of charges
q = cv
The "bath" or extracellular space is said to be this before any voltage is applied
At isopotential
If the membrane is at -88mv this ion wants to leak in and this ion wants to leak out in order to maintain this voltage over time?
Potassium
or
Sodium want to leak in but is pumped out, while potassium wants to leak in and out.
This is good for short distances communication and happens in this region of the neuron
Synaptic potential; Dendrites and soma
Membrane channels can be describes as this
Parallel conductors (or resistors)
The peak of the action potential can be described by this equation
(Vm -Ena) = 0
If EX+ is -50 and Vrest is -10 to maintain this Conc. gradient over time X+ moves in this direction and the membranes moves it in this direction.
leaks out; pumped in
This determines the value of the resting potential when more than one ion is permeable at rest
The Goldman equation
A short dendrite with a large diameter can be represented by
A Large Lambda
These class of voltage-gated channels allow for the current flow of these ions to flow outward
Delayed rectifiers; Potassium
The down phase of the graded potential (synaptic potential) can be described by this formula
Tau = RM * CM
Electrochemical equilibrium describes the event of these two forces
When the electrical force is equal and opposite to the chemical force
When you decrease Cm, graded potentials will reach this sooner
Threshold
This begins with a depolarized membrane, change in the membrane structure, gates open, increases current, rinse and repeat.
The Hodgkin Cycle
These ion's channels are voltage AND time dependent while these ion's channels are only voltage-dependent
Na+ ; K+
If you are given Vm and Conc. of the ion using this formula will give you the theoretical equilibrium potential of that ion
The Nernst Equation
To calculate the value of the current in relation to the membrane resistance, for two spherical neurons you would use these equations
Rinp = RM/Sa ; V= I * Rinp
The introduction of a myelinated axon will decrease this but increase this
membrane Capacitance; membrane resistance
When injecting a series of current pulses into the membrane this influences the membrane ability's to reach AP
The refractory period
These type of receptors when activated will activate 2nd messenger cascade system that Ultimately phosphorylates a separate ion channel and leads to channel activity
G-protein coupled receptors
As AP begins voltage and time-dependence of conductance can be determined for different ions by using this formula
Im(t)= gm(t) [Vm(t)-Eion]
This is what happens when you reduce the extracellular sodium concentration and increased the intracellular potassium concentration
decrease the spike of the Ap and increase the spike of the repolarization and AHP