Mastering Nerve Cell Electrical Potentials

20 Questions

Which of the following is the main component of cell membranes?

Phospholipid bilayer

What is the capacitance of cell membranes?

10-2 Fm-2

What is the resting membrane potential of nerve cells?

-70 to -90 mV

Which ion is high in the extracellular fluid?

Sodium (Na+)

Which ion is high in the intercellular fluid?

Potassium (K+)

What happens to the cell membrane permeability during an active state?

Increases suddenly to Sodium

What is the peak value of the action potential during an active state?

+40 mV

What is the duration of the action potential peak?

0.3 ms

What is the shape and peak size of the action potential dependent on?

None of the above

What is actively pumped across the membrane during sodium-potassium pumping?

Sodium (Na+)

Which process consumes energy and takes about 50ms to restore the resting Na+ and K+ concentrations?

Pump reestablishment of ions

What is the critical threshold value for the response of an axon to a stimulus?

-55 mV

What is the name given to the analog network of resistors and capacitors in the axon?

RC network

What happens to the changes in potential difference across the capacitors as one goes farther from the stimulus?

They decrease in magnitude

What is the potential difference reached by a stimulus above the threshold level?

+50 mV

What is the signal conduction velocity directly proportional to?

Axon diameter

What is the signal conduction velocity inversely proportional to?

Capacitance

What is the name of the process that gradually changes the potential difference across the capacitors?

Capacitor charging

What is the name of the current pulse associated with an active potential that travels the length of the axon without attenuation?

Action potential

What is the name of the process that gradually reestablishes the resting Na+ and K+ concentrations?