An action potential is caused by either threshold or suprathreshold stimuli upon a neuron. It consists of four phases: depolarization, overshoot, and repolarization. An action potential propagates along the cell membrane of an axon until it reaches the terminal button.
Table of Contents
What are the 4 steps of an action potential?
An action potential is caused by either threshold or suprathreshold stimuli upon a neuron. It consists of four phases: depolarization, overshoot, and repolarization. An action potential propagates along the cell membrane of an axon until it reaches the terminal button.
What are the 5 steps of an action potential?
The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase.
What causes an overshoot in action potential?
Overshoot: Because of the high permeability to sodium, the membrane potential goes to a value that is close to the Equilibrium potential for sodium (~ +55 mV). Falling Phase: First, the voltage-gated sodium channels inactivate.
What are the 7 steps of an action potential?
7 Cards in this Set
| STEP 1 | Threshold stimulus to -55mv | Stimulus |
|---|---|---|
| STEP 4 | At +30mv, Na channels close and K ions channels open | K ions |
| STEP 5 | K floods out of the cell | Out of cell |
| STEP 6 | Hyperpolarization to -90mv | Hyper |
| STEP 7 | K channels close and tge resting potential is re-established at -70 | Re-established |
What are the four steps of an action potential in order quizlet?
Terms in this set (4)
- Step 1 – Resting Potential. Sodium and potassium channels are closed.
- Step 2 – Depolarization. Sodium channels open in response to a stimulus.
- Step 3 – Repolarization. Na+ channels close and K+ channels open.
- Step 4 – Resting Conditions. Na+ and K+ channels are closed.
What are the steps of action potential quizlet?
Terms in this set (6)
- Step One: Reaching Threshold.
- Step Two: Depolarization.
- Step Three: Sodium Channels Close and Potassium Channels Open.
- Step Four: Active Sodium and Potassium Pumps Begin to Start Repolarization.
- Step Five: Hyperpolarization.
- Step Six: Resting Potential.
What is undershoot in action potential?
The voltage-gated potassium channels stay open a little longer than needed to bring the membrane back to its resting potential. This results in a phenomenon called “undershoot,” in which the membrane potential briefly dips lower (more negative) than its resting potential.
What are the 5 steps that take place in transmitting information across a synapse?
Neurotransmitter release from the presynaptic terminal consists of a series of intricate steps: 1) depolarization of the terminal membrane, 2) activation of voltage-gated Ca2+ channels, 3) Ca2+ entry, 4) a change in the conformation of docking proteins, 5) fusion of the vesicle to the plasma membrane, with subsequent …
What does the overshoot mean?
1 : to pass swiftly beyond. 2 : to shoot or pass over or beyond so as to miss. Other Words from overshoot Synonyms Example Sentences Learn More About overshoot.
Which of the following is responsible for the falling Repolarizing phase of the action potential?
The electrical gradient is in a direction that would tend to move K+ out of the cell. Which is most directly responsible for the falling (repolarizing) phase of the action potential? The permeability to K+ increases greatly while that to Na+ decreases.
What are the 7 steps of a nerve impulse?
Terms in this set (6)
- Resting neuron: The plasma membrane at rest is polarized.
- Action potential initiation and generation: A stimulus depolarizes the neurons membrane.
- Action potential initiation and generation:
- Propagation of the action potential:
- Repolarization:
- Repolarization: