Muscular P4

What happens when a nerve impulse reaches the axon terminal of a motor neuron?

• Calcium channels open, and calcium enters the axon terminal.

• Sodium channels open, and sodium enters the axon terminal.

• Potassium channels open, and potassium exits the axon terminal.

• Magnesium channels open, and magnesium enters the axon terminal.

What is the role of calcium ions in the transmission of nerve impulses to muscles?

• They cause synaptic vesicles to release acetylcholine.

• They cause the muscle to contract directly.

• They inhibit the release of neurotransmitters.

• They depolarize the muscle membrane.

What happens to sodium ions when the cell returns to its resting state?

• Sodium ions diffuse out of the cell.

• Sodium ions diffuse into the cell.

• Sodium ions remain unchanged.

• Sodium ions are converted to potassium ions.

What is the function of the sodium-potassium pump during the resting state of a cell?

• It moves sodium and potassium ions back to their original positions.

• It moves calcium ions into the cell.

• It moves chloride ions out of the cell.

• It moves magnesium ions into the cell.

What is the role of acetylcholine in muscle contraction?

• It binds to receptors on the muscle cell membrane.

• It inhibits muscle contraction.

• It breaks down calcium ions.

• It depolarizes the axon terminal.

What happens when acetylcholine binds to receptors on the muscle cell membrane?

• Sodium channels open, allowing sodium to enter the cell.

• Potassium channels open, allowing potassium to exit the cell.

• Calcium channels open, allowing calcium to enter the cell.

• Magnesium channels open, allowing magnesium to enter the cell.

What is the result of sodium entering the muscle cell?

• The muscle cell becomes depolarized.

• The muscle cell becomes hyperpolarized.

• The muscle cell remains unchanged.

• The muscle cell releases acetylcholine.

What happens to acetylcholine after it has bound to the muscle cell membrane?

• It is broken down by enzymes.

• It remains bound indefinitely.

• It is converted into calcium ions.

• It is absorbed into the muscle cell.

What is the role of the enzyme that breaks down acetylcholine?

• It prevents continuous muscle contraction.

• It enhances muscle contraction.

• It converts acetylcholine into sodium ions.

• It depolarizes the muscle cell.

What is the effect of depolarization on the muscle cell?

• It triggers muscle contraction.

• It inhibits muscle contraction.

• It causes the muscle cell to release potassium.

• It causes the muscle cell to release calcium.