Neurons Action potential 9 Steps Step 1 Signal

Neurons

Action potential • 9 Steps – Step 1 • Signal is received • Pain

Action potential • Step 2 – Axon Membrane – Chemical gates • Allow electrically charged particles to enter, or can keep them out

Action Potential • Step 3 – Ions • Chemical particles that have electrical charges – Opposite charges attract – Like charges repel – Sodium and protein

Action Potential • Step 4 – Resting State • Axon has a charge, or potential • Separates positive ions on the outside from negative ions on the inside – Sodium Pump- keeps axon at its resting state

Action Potential • Step 5 • Action Potential – Tiny electrical current that is generated when the positive sodium ions rush inside the axon. – Inside becomes positive, outside becomes negative

Action Potential • Step 6 – Nerve impulse – Series of separate action potentials that take place segment by segment as they move down the length of an axon

Action Potential • Step 7 – All-or-none Law – If an action potential starts at the beginning of an axon, it will continue to the end

Action Potential • Step 8 – Nerve impulse – Each separate action potential occurs in order – After each action potential, that part of axon returns to resting state – Breaks in myelin sheath allow action potential to take place

Action Potential • Step 9 – End Bulbs and Neurotransmitters – Once action potential reaches the end of the axon, the end bulbs release neurotransmitters