1. Please draw the action potential graph (label everything) and describe what happens to the cell membrane during an action potential. I need ion flow in sequence and charges across the membrane, as well as a description of what is going on at each stage (ex. Name of the stage, which ion gates are open, which wat ions are flowing).

7. When the absolute threshold is reached, _______________________ allowing a rapid influx of positively charged sodium ions and changing the membrane potential of the neuron from -70mV to +40mV.

7. Draw a standard action potential compared to an action potential whose voltage gated potassium channels have been inactivated with tetraethylammonium (TEA). a. Draw the curves. Label all axes. b. Describe how and why they are different.

9. If sodium permeability (Pna) increases compared to normal, what is the effect on the membrane potential? (determine: change in charge on the inside of the membrane and polarity)

6. If the action potentials shown in the diagram below occur sequentially and in close temporal proximity, what will be the final result in cell D? In this notation, < indicates an excitatory an inhibitory synapse. Focus on overall effects – excitation and inhibition – don't worry about quantifying responses here. (Hint: you may want to identify what is happening at each cell and then how that will be affected by the activation of the previous cell) synapse and indicates Above Above threshold stimulation Above threshold stimulation threshold stimulation D

There is no inward current at a membrane potential of +65mV because: The membrane potential is near or at the equilibrium potential for Na+ The membrane potential is near or at the equilibrium potential for neither Na+ or K+ The membrane potential is near or at the equilibrium potential for both Na+ and K+ The membrane potential is near or at the equilibrium potential for K+