S H E E T
NAME_________________________________ LAB TIME/DATE ________________________
Neurophysiology of Nerve Impulses
Match each of the definitions in Column A with the appropriate term in Column B. Column A term that refers to a membrane potential of about 70 mv
a. b. c. d.
threshold sodium potassium resting membrane potential absolute refractory period depolarization
reversal of membrane potential due to influx of sodium ions major cation found outside of a cell minimal stimulus needed to elicit an action potential period when cell membrane is totally insensitive to additional stimuli, regardless of the stimulus force applied major cation found inside of a cell
f. 2. Fill in the blanks with the correct words or terms.
Neurons, as with other excitable cells of the body, have two major physiological properties: __________________ and _________________. A neuron has a positive charge on the outer surface of the cell membrane due in part to the action of an active transport system called the _______________________________. This system moves ____________________ out of the cell and _________________ into the cell. The inside of the cell membrane is negative, not only due to the active transport system but also because of __________________, which remain negative due to intracellular pH and keep the inside of the cell membrane negative. 3. Why don’t the terms depolarization and action potential mean the same thing?
What is the difference between membrane irritability and membrane conductivity?
Review Sheet 3
5. Why does a nerve’s action potential increase slightly when you add 1.0 V to the threshold voltage and stimulate the nerve?
6. If you were to spend a lot of time studying nerve physiology in the laboratory, what type of stimulus would you use, and why?
7. Why does the addition of sodium chloride elicit an action potential?
8. What was the effect...