Neuronal Signalling Flashcards
Excitable cells have
Voltage across membranes
The cell membrane is selectively
Permeable
Because the Cell membrane is selectively permeable this means ions need
Ion channels, they have specific channels for specific ions
What is the resting potential of a cell
-70 to -90 mv
What Ion is higher outside the cell
Sodium
What ion is higher inside the cell
Potassium
What is sodium is preferred equilibrium potential
+60 mv
What is potassiums preferred equilibrium potential
-90mv
What is calciums preferred equilibrium potential
+123mv
What is chlorine preferred equilibrium potential
-40 MV
What happens to the preferred equilibrium potential if too ion channels are open
Then the middle ground of the ions is found
What is the resting membrane potential for neurons
-90 mv
Why does action potentials occur
Due to rapid changes in membrane potential
Stages of action potential
Resting stage Stimulus Depolarisation Action potential Repolarisation Refractory period (hyperpolerisation) Resting state
What happens in depolarisation
Inside of the cell becomes less -
What happens when delayed rectifier K+ channels open
Increase in K+ and decrease in Na+ permeability so membrane potential becomes less negative
The synapse has gap
Junctions for electrical communication
Neurotransmitters are released by a
Neuron
+ synthesis occurs in the
Soma or axon terminal
+ synthasis if s transported into
A vesicle for storage
What is signal termination
The removal of neurotransmitter or degraded by an enzyme
Signal termination prevents the signal from
Constantly being sent
