Karteikarten
cell circuits - dynamic cell
Karten in diesem Stapel (5)
- 1membranes have 3 basic equivalent electrical components: batteries, resistors & capacitors - capacitors store charge - resistors in series behave as ion channelsbattery can remade from ion conc gradient across membrane that is selectively permeable to that ion
- 2Nernst equation Ex = (RT/zF)ln(xo/xi)x = ion
Ex = equilibrium potential for x
R = universal gas constant
T = absolute temp
z = valence of ion
F = faradays constant
Xo = conc of x outside cell
xi = conc of x inside cell - 3—importance:
- changes in membrane potential determine if action potential will occur or not
- excitatory neurotransmitters cause small changes in membrane potentials which can sum & cause an action potential to occur
- action potentials are required for correct functioning of the brain, heart & skeletal muscle - 4Omh's law - relationship between voltage, current & resistance V=IR - resistance = 1/conductance - important for understanding ion channelsvoltage round a circuit loop
- each point in space, or around circuit has unique voltage at a given time = electrical potential energy
- if go completely around loop, you get back to the same voltage
battery = converts chemical energy into electrical energy, creating voltage (potential) difference between its terminals, so voltage increases from - to + terminal
- work must be done to force current to flow through resistor, potential energy is dissipated (converted to heat) - voltage decreases along resistor in direction of current flow - 5capacitor = phospholipid membrane + ionic solutions either side - parallel plate capacitor = insulating dielectric layer sandwiched between two conducting layerstemporal integration
- adding up a signal over time
- key process in neuroscience/electrophysiology
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- Karteikarten am cell circuits - dynamic cell, erstellt von michaela minkin am 27/05/2018.
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- michaela minkin
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