2-Minute Neuroscience: Membrane Potential

What does membrane potential refer to?

• a. The energy produced by a neuron

• b. The difference in electrical charge between the inside and outside of a neuron

• c. The flow of blood in a neuron

• d. The temperature of the neuron

Which of the following ions is represented by green circles in the video?

• a. Sodium ions

• b. Potassium ions

• c. Chloride ions

• d. Organic anions

When a neuron is at rest, how does the inside charge compare to the outside charge?

• a. It is more positively charged

• b. It is neutral

• c. It is more negatively charged

• d. It fluctuates constantly

Which ion is more prevalent outside the neuron when it is at rest?

• a. Potassium ions

• b. Sodium ions

• c. Organic anions

• d. Chloride ions

What type of ions are organic anions?

• a. Positively charged ions

• b. Charged molecules with no relevance

• c. Neutral ions

• d. Negatively charged ions

What is the resting membrane potential of an average neuron?

• a. 0 millivolts

• b. -70 millivolts

• c. +70 millivolts

• d. -90 millivolts

How many sodium ions are pumped out of the cell by the sodium-potassium pump?

• a. One

• b. Two

• c. Three

• d. Four

What is the role of ion channels in the context of potassium ions?

• a. They prevent potassium from moving across the membrane

• b. They facilitate the easy movement of potassium across the cell membrane

• c. They only allow sodium ions to pass

• d. They maintain a positive charge in the neuron

What happens to potassium ions when they reach equilibrium?

• a. They stop moving into the cell

• b. They continue to flow into the cell

• c. They are completely blocked from leaving the cell

• d. They move out of the neuron until they reach a positive charge

What mechanism helps maintain the membrane potential?

• a. Calcium pump

• b. Sodium-potassium pump

• c. Proton pump

• d. Chloride transport