Which of the following occurs when an action potential arrives at the presynaptic terminal?

When an action potential reaches the presynaptic terminal, it causes neurotransmitter to be released from the neuron into the synaptic cleft, a 20–40nm gap between the presynaptic axon terminal and the postsynaptic dendrite (often a spine).

Which ions flow will cause action potential?

The principal ions involved in an action potential are sodium and potassium cations; sodium ions enter the cell, and potassium ions leave, restoring equilibrium. Relatively few ions need to cross the membrane for the membrane voltage to change drastically.

Which of the following occurs when an action potential arrives at the presynaptic terminal quizlet?

Which of the following occurs when an action potential arrives at the presynaptic terminal? Synaptic vessels migrate to the plasma membrane and release acetylcholine.

What happens to the flow of ions when threshold is reached?

If the threshold of excitation is reached, all Na+ channels open and the membrane depolarizes. The membrane becomes hyperpolarized as K+ ions continue to leave the cell. The hyperpolarized membrane is in a refractory period and cannot fire.

What happens when the action potential reaches the end of the axon at the axon terminal?

When the action potential reaches the end of the axon (the axon terminal), it causes neurotransmitter-containing vesicles to fuse with the membrane, releasing neurotransmitter molecules into the synaptic cleft (space between neurons).

When an action potential arrives at the axon terminal?

When an action potential, or nerve impulse, arrives at the axon terminal, it activates voltage-gated calcium channels in the cell membrane. Ca2+start text, C, a, end text, start superscript, 2, plus, end superscript, which is present at a much higher concentration outside the neuron than inside, rushes into the cell.

Which ion is entering the axon terminal at A and what effect does it have?

what ion entering the axon terminal at A, and what effect does it have? Calcium ion channels open when the membrane is depolarized, and the inflow of Ca2+ leads to the release of neurotransmitters from synaptic vesicles.

Which of the following happens when an action potential causes depolarization at a neuron?

Explanation: During the initial phase of an action potential, voltage-gated sodium channels open and allow sodium ions to enter the cell. This causes the membrane potential to rise to a positive value, resulting in depolarization. Next, voltage-gated potassium channels open and potassium ions rush out of the cell.

What happens to the membrane immediately adjacent to the action potential?

An action potential generates local currents that tend to DEPOLARIZE the membrane immediately adjacent to the action potential. Action potential propagation to occur in one direction.

What happens at threshold during an action potential?

An action potential occurs when a neuron sends information down an axon, away from the cell body. When the depolarization reaches about -55 mV a neuron will fire an action potential. This is the threshold. If the neuron does not reach this critical threshold level, then no action potential will fire.

When an action potential reaches the end of an axon an electrical impulse is then converted into a quizlet?

when action potentials reach the end of an axon (the axon terminals), they stimulate the release of neurotransmitters. These chemical messengers carry a message from the sending neuron across a synapse to receptor sites on a receiving neuron.