Question

the brief period during which a local area of an axons membrane resists re - stimulation is called the __________ period.
repolarization
refractory
action
resting

question 17
which membrane receptor acts to directly change ion permeability when stimulated?
g - protein - coupled receptors
ionotropic receptor
gated - channel receptor
metabotropic receptor

question 18
a synapse can occur only between an axon and:
another axon.
a dendrite.
any of the above.
a cell body.

Explanation:

• For the first question, the refractory period is when an axon's membrane resists re - stimulation. Repolarization is the return of the membrane potential to its resting state, action is related to action potential, and resting is the normal unstimulated state.
• For the second question, gated - channel receptors directly change ion permeability when stimulated. G - protein - coupled receptors act through a secondary messenger system, ionotropic receptors are a type of gated - channel receptor but the more general term here is gated - channel receptor, and metabotropic receptors act through second - messenger systems.
• For the third question, a synapse can occur between an axon and another axon, a dendrite, or a cell body.

Answer:

• Question 1: B. refractory
• Question 17: C. Gated - channel receptor
• Question 18: C. any of the above