When a neuron is in the relative refractory period, a stimulus has to be stronger than normal to start an action potential. However, a stimulus during the start of the relative refractory period has to be even stronger than one during the end of the relative refractory period. Explain this difference.

How do we distinguish a strong stimulus from a weak one when the information about both stimuli is relayed by action potentials that are all the same amplitude?

Describe how depolarization occurs along an unmyelinated neuronal axon

Why can a greater-than-normal stimulus trigger an AP during the relative refractory period but not during the absolute refractory period?

a channel can be gated mechanically, voltage or by a ligand. When you hear a sound all three of these type channels are being utilized. Explain generally where/how each of these channels are being utilized starting from hearing the sound, through travelling down a nerve to transmission to another nerve.

Two axons are tested for propagation velocities (speeds). One carries action potentials at 50 meters per second, the other at 1 meter per second. Which axon is myelinated?

Distinguish between insulation by oligodendrocyte or Schwann cells. Relate myelination to signal speed.  Describe the myelin-related terms: neurilemma, nodes of Ranvier, internodes, nonmyelinated

Myelin sheaths function to electrically insulate neurons. Compare and contrast the myelination in the CNS and PNS (hint: include the cell types and their specific properties).

Gustatory neurons are stimulated by_____which causes the opening of____gated ion channels. These cell fire______

(b) Use Figure Q1(b) of an action potential to answer questions (i) until (iv) below. Choose the correct letter to represent each condition. (i) The neuron cannot fire an action potential because it is in a refractory period. (ii) The membrane potential is about -70 mV. (iii) The voltage-gated Na+ channels activation gates are closed, but the inactivation gates are open. (iv) Both gates of the voltage-gated Na+ channels are open. C Threshold B A E Figure Q1 (b)