Week 2 Flashcards
two signals can travel into the cell body
excitatory and inhibitory signals
excitatory signals
cell more likely to fire
inhibitory signals
cell less likely to fire
signal reaches axon hillock
summation occurs
summation?
sum of all incoming signals determines whether the neuron fires
threshold to fire?
-55mV
beginning value of the neuron
-70mV
resting membrane potential
when the cell is more negatively charged compared to outside the cell
ions crucial to sending signal down an axon
Potassium K+ and Sodium Na+
When the K+ is pulled in both directions
the cell is at rest
action potential
change in voltage in the cell, taking place at one section of the cell at a time
Volted gated sodium channels
doorway triggered by certain electrical charge - they open at -55mV
Propagation
process of the sodium gates opening
water outside vs inside the cell
salty water vs different kind of water with particles in it
Ion channels
allow specific ions through
Fundamental properties of how ions move
concentration gradient and electrical gradient
concentration gradient
sodium wants to go where there is less of itself until equilibrium occurs
passive diffusion
natural process where ions move from high to low concentration till equilibrium occurs without the need for external energy
electrical gradients
charged particles will move across the membrane until electrical equilibrium has occured
What does K+ want to do
Wants to go out of the cell because there is less K+ out there (CF). Wants to stay in the cell and make it as positive as possible (EF).
Depolarization
When the cell becomes crazy positive
When do the sodium channels close
at 30mV
Repolarization
Takes the mV back to 0, overshoots to -80mV
Refractory period
Trying to get back to the resting potential
