Test 2 Short Answer

What is step 1 of nerve signal transmission?

An action potential begins when a stimulus causes sodium channels to open, allowing sodium ions to enter the neuron and make the inside more positive. This is called depolarization.

What is step 2 of nerve signal transmission?

Next, sodium channels close and potassium channels open, allowing potassium ions to leave the neuron, making the inside more negative again. This is called repolarization.

What is step 3 of nerve signal transmission?

The neuron may briefly become more negative than its resting potential, called hyperpolarization.

What is step 4 of nerve signal transmission?

Potassium channels then close, and the sodium-potassium pump maintains the ion gradients and helps restore the resting state.

What is step 5 of nerve signal transmission?

The nerve impulse travels along the axon, and in myelinated neurons, saltatory conduction speeds up transmission by allowing the impulse to jump from one node of Ranvier to the next.

What is step 6 of nerve signal transmission?

When the impulse reaches the axon terminal, calcium channels open, allowing calcium ions to enter and trigger synaptic vesicles to release neurotransmitters into the synaptic cleft through exocytosis.

What is step 7 of nerve signal transmission?

The neurotransmitters diffuse across the gap and bind to receptors on the postsynaptic neuron, opening ligand-gated ion channels.

What is step 8 of nerve signal transmission?

If the stimulation reaches threshold, a new action potential is triggered in the next neuron.