L5 - Physiology Of Neurons Flashcards
How does Lidocaine work
It blocks the sodium channels in pain neurons therefore raising threshold and lowering excitability
How does carbamazepine work
It inactivate sodium channels therefore raising action potential threshold and lowering excitability
How does quinidine work
It works by lowering conduction velocity which extends the refractory period
How do signals move in electrical synapses
Via gap junctions
In which direction do you electrical synapses work
They are bidirectional
Define spatial summation
The addition of lots of small signals Generating an action potential From all the neurons synapsing on it
Define temporal summation
When the input is firing fast enough so that the receiving neuron can add together all the signals reaching threshold
Which channels maintain resting potential
Inward rectifier potassium channels and sodium potassium pump
What happens at after hyper polarisation
Delayed rectifier potassium channels open allowing potassium out bringing the membrane back to resting potential
What defines the intensity of activity in a neuron
The firing frequency
Why do you want lengthy signup tick currents create a higher threshold potential
Due to accommodation of sodium current which inactivates during the slower subthreshold depolarisation
Define threshold
The voltage above which an action potential fires
What are the two forces acting on an ion
The diffusional force in the electrical force
What is equilibrium potential
When the number ions coming into the cell is equal to the number of ions leaving the cell.
The diffusional force is equal to the electrical force
What is the equilibrium potential for sodium
+60 millivolts
