Action potentials

Action Potential

Electrical charge that runs down the axon from the axon hillock to the terminal buttons.

Neural Signals

If we were made of a good conducting material, our signals would travel at the speed of light. The further the impulse has to travel, the longer it takes to get there, also the neuron has to repeatedly pulse the charge.

Resting potential

The difference in electrical charge between the inside and outside of the cell. When the cell is at rest, the inside of the cell is more negatively charged as compared to the outside.

Electrical Gradient

Difference in electrical charges between the inside and outside of the cell.

Concentration Gradient

Difference in distribution of ions across the neuron’s membrane.

Ion Channels

A barrier that can be open, closed, or inactivated (locked) that blocks or lets in the positive charge waiting on the outside of the neuron.

Why does the body want to stay in resting potential

The body wants to stay in resting potential because when the neuron is stimulated, it is instantaneous.

Depolarization

When a signal is detected, the ion channels open allowing for some sodium to enter, raising the charge positively at the Threshold of excitation.

Repolarization

Once depolarization happens, the potassium and sodium pumps start to pump all of the positive ions back out, which allows the axon to go back to Resting Potential.

Sodium and potassium pumps

Pumps that push sodium out and potassium ions in the cell to make the inside negative again.

Hyperpolarization

When the cell does too good of a job getting the inside negative, and goes past -70.

Propagation of an action potential

When the sodium in the first part of the axon travels to the next part, repeating the process of action potential along the axon.

Nodes of Ranier

Gaps in myelin that facilitate the rapid conduction of nerve impulses.

Saltatory conduction

Jumping of action potential from one node to another.

All-or-none law

Once an action potential is triggered in an axon, it is propagated without decrement to the end of the fiber.

Rate Law

The stronger the stimulus, the faster the rate at which the axons will fire.