Action Potentials and Neuron Function

The video explains nerve impulses as electrical signals in neurons, focusing on the movement of ions across cell membranes. It covers resting potential, depolarization, repolarization, and the refractory period, highlighting the role of sodium and potassium ions. Action potentials are described as wave-like patterns, with the importance of reaching threshold potential for neuron firing. The video concludes with hyperpolarization and the energy demands of maintaining resting potential.

What is a nerve impulse primarily composed of?

• Movement of proteins

• Movement of charged particles

• Flow of water

• Flow of electrons

What is the charge inside a neuron at rest?

• Positive 70 millivolts

• Negative 70 millivolts

• Positive 55 millivolts

• Negative 55 millivolts

What triggers the opening of the voltage-gated sodium channels?

• Resting potential

• Depolarization

• Hyperpolarization

• Repolarization

What happens to the cell's internal charge during depolarization?

• It becomes more negative

• It becomes more positive

• It remains the same

• It fluctuates randomly

What is the role of the sodium-potassium pump during the refractory period?

• To restore resting potential

• To trigger another action potential

• To repolarize the cell

• To depolarize the cell

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

• Two

• Five

• Four

• Three

In which direction do action potentials move?

• They do not move

• From dendrites to axon terminals

• In both directions

• From axon terminals to dendrites

What is the threshold potential for an action potential to begin?

• Positive 70 millivolts

• Positive 55 millivolts

• Negative 55 millivolts

• Negative 70 millivolts

What is the term for the period when no additional action potentials can be sent?

• Depolarization period

• Repolarization period

• Resting period

• Refractory period

What tool is used to display the membrane potential over time?

• Microscope

• Telescope

• Oscilloscope

• Stethoscope