1. How Neurons and Synapses Work

2. Excitable Cells Neurons, glands, and muscle cells
Can carry an electrical charge when stimulated

3. Local Potential
When a stimulus causes a change in the body
If its big enough it causes an action potential

4. Caused by different ions entering and exiting the cell
Action Potential
Series of permeability changes within the neuron that carry the electrical impulse down the axon
Caused by different ions entering and exiting the cell
Na+ moves in, while K+ moves out

5. Things that Speed up Impulse Conduction
Myelin Sheath: Causes less ion channels to have to open and close in order to move the signal down the axon
Wider Axon: Allows for ions to flow quicker through the axon

6. Refractory Period
A period of time following stimulation in which a nerve cannot send another signal

7. Chemical Synapses
Once the action potential reaches the axon terminal neurotransmitters are released from vesicles via exocytosis and are released into the synapse

8. Chemical Synapses
Neurotransmitters bind to the cell receiving signal and causes gates to open or close, either exciting or calming down the receiving cell

9. Chemical Synapses
Neurotransmitter is taken away from the synapse by an enzyme, to stop the neurotransmitter from continuously binding to the receiving cell

10. Important Neurotransmitters
Acetylcholine: Controls skeletal muscles
Norepinephrine: Control smooth and cardiac muscle
Dopamine: Controls motivation and mood
Epinephrine: Adrenaline; Increased fight or flight response
Serotonin: Regulates mood and anxiety
Endorphins: Increase pleasure and decrease pain

11. Synapse Video