Nerve Impulses and Action Potentials Quiz

What are the signals that travel very rapidly along the cell surface membrane from one end of the cell to the other?

• Heat energy

• Action potentials

• Chemical reactions

• Flow of electrons

Answer explanation

Action potentials are signals that travel rapidly along the cell surface membrane from one end of the cell to the other.

What is the brief change in the potential difference across the cell surface membranes of neurons and muscle cells called?

• Resting potential

• Electrical current

• Action potential

• Chemical gradient

Answer explanation

Action potential is the brief change in potential difference across the cell surface membranes of neurons and muscle cells.

What is the potential difference between the inside and outside of a resting axon typically?

• -30 mV to -40 mV

• +60 mV to +70 mV

• 0 mV

• -60 mV to -70 mV

Answer explanation

The potential difference between the inside and outside of a resting axon is typically -60 mV to -70 mV. This is the correct choice.

What constantly moves sodium ions out of the axon and potassium ions into the axon?

• Magnesium carriers

• Chloride transporters

• Calcium channels

• Sodium–potassium pumps

Answer explanation

Sodium-potassium pumps constantly move sodium ions out of the axon and potassium ions into the axon, ensuring proper nerve cell function.

What type of proteins respond to changes in the potential difference across the membrane and are closed during resting potential?

• Enzyme-linked receptors

• Ligand-gated channel proteins

• Mechanically-gated channel proteins

• Voltage-gated channel proteins

Answer explanation

Voltage-gated channel proteins respond to changes in membrane potential and are closed during resting potential.

What is the result of the presence of many large, negatively charged molecules inside the cell?

• Overall excess of negative ions inside the membrane

• No effect on the distribution of ions

• Equal distribution of ions inside and outside the membrane

• Excess of positive ions inside the membrane

Answer explanation

The presence of large, negatively charged molecules inside the cell leads to an overall excess of negative ions inside the membrane.

What influences the inward movement of sodium ions during an action potential?

• Positive charge inside the membrane only

• Both concentration gradient and negative charge inside the membrane

• Negative charge inside the membrane only

• Steep concentration gradient only

Answer explanation

The inward movement of sodium ions during an action potential is influenced by both the concentration gradient and the negative charge inside the membrane. This allows for the propagation of the electrical signal.