The absolute refractory period is the result of voltage gated channels being , 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 mV (resting) to mV and back again to the resting membrane potential. This is the result of a change in membrane permeability first to ions then to ions due to the opening of gated channels.

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

Lidocaine differs from TTX in that it and is .

action potentials are recorded at  when TTX is applied between R1 and R2 because it propagation of action potentials from

Hyperpolarized membranes are threshold and require a stimulus that is to generate an action potential.

Activity 4: TTX blocks diffusion of through channels.

Activity 8:  When magnesium was added to the extracellular solution, _______.

When you burn your finger on a hot stove, you fell sharp, immediate pain, which later becomes slow, throbbing pain. These two types of pain are carried by different pain neurons.  The sharp immediate pain is the result of action potentials propagated along , , Type fiber neurons, while the slow, throbbing pain is transmitted via , , Type neurons.