Trace airflow from the lungs to produce a vowel sound out through the mouth.

airstream mechanism or human speech system

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.