Mg++ [a] the effect of extracellular calcium by blocking [b] and [c] neurotransmitter release.

What change in membrane potential triggers the action potential? 

Under resting conditions potassium ions move ___ the neuron through ____ channels.

Put the events occurring at a ligand gated channel in the correct order.

Stronger stimuli are able to increase the frequency of action potentials by intruding on the:

What happened to the amount of neurotransmitter release when you switched from the extracellular fluid with no Ca++ to the extracellular fluid with low Ca?

The absolute refractory period is the result of [x] voltage gated channels being [y], which means that they cannot be opened regardless of stimulus strength.  (refer to the Vander textbook if needed.)

Activity 5:  How does the absolute refractory period ensure directionality of action potential propagation? Include the role of Na+ voltage gated channels.

The action potential changes the membrane potential from [x] mV (resting) to [y] mV and back again to the resting membrane potential. This is the result of a change in membrane permeability first to [z] ions then to [a] ions due to the opening of [b] gated channels.

Why is a long refractory period beneficial for cardiac muscle? Vanders’s Human Physiology textbook is a good source for this question.