Action potiential Flashcards
What causes a change in membrane potiential
A change in voltage gated channel activity
How does an action potiential work
It is triggered when a cell reaches threshold
What happens in milk fever cows?
Calcium concentration decreases in the extracellular fluid, this will elevate the resting membrane potiential of the cell in a calcium deficient cow. If resting membrane potiential is increased enough it will exceed threshold which means action potientials will be triggered which causes excitability and unpredictable movement.
Movement of action potientials is facilitated by
Positive charge on outside of cell membrane and negative charge on inside of cell membrane
What happens when an action potiential moves through the membrane
Current loops are repeated on other areas of the membrane and flips back to initial point of depolarisation then it hits a point in the membrane which is sitting in its absolute refractory period so you cant stimulate another action potiential.
What part of a neuron has high conc of sodium and potassium channels
Axon hillock
What part of the cell is most likely to fire an AP
Axon hillock.
What do u need in order to form a current loop
Separation of charge in the membrane
What is myelination
When a neuron is insulated around the axon, cant form a current loop
What are the gaps between insulated layers called
Nodes of ranvier
What are nodes of ranvier
Breaks in the myelination and the separation of charge across the cell membrane so can form a current loop
What is saltorary conduction?
When an action potiential is formed at gaps, it will depolarise that node of ranvier and then jump to the next one and depolarise that and this happens in both directions which means it is bidirectional
What is the advantage of saltatory conduction
Faster transmission and preserves energy
Divergent pathway
One neuron passes information to multiple neurons
Convergent pathway
When multiple neurons pass info to one neuron
