Spread of the Nerve Impulse Flashcards
What are the different types of neuronal phenotype?
Multipolar neuron
Bipolar neuron
Pseudounipolar neuron
Function of dendrites?
Branches of nerve cell that receives connections from other nerve cells
Function of axon
Extension of a single nerve cell that enables it to carry electrical signals over long distances
What is passive conduction?
Electrical activity down a cable, heat along a rod
What is active conduction?
Generation of an action potential by opening of ion channels
Why do we need action potentials?
Passive conduction can only travel a short distance
What happens in the absolute refractory period?
The time when the sodium channels are closed and cannot open due to the inactivation gate shutting
What happens in the relative refractory period?
Because of the potassium taking the membrane potential lower than the resting potential, it requires a larger stimulation to reach the threshold potential again
What is capacitance?
Capacity to store charge
How does capacitance effect electrical conduction?
The more surface areas on an axon the higher the capacitance
The higher the capacitance the harder it is for charge to cross over the membrane
What creates myelination in the CNS?
Oligodendrocytes
What creates myelination in the PNS?
Schwann cells
What does myelination do?
Can pass current faster as there is less charge lost though the membrane
What happens at the node of Ranvier?
Action potential is generated actively and then can passively pass though the myelinated portion of neuron
What can axons vary in?
Diameter and myelination changing speed
