What is an Action Potential in the Nervous System?

As part of your Level 3 Anatomy and Physiology Exam, you need to understand the function of the nervous system including what is an action potential.

If you’ve googled “Action Potential” I guarantee you have a complicated and in-depth doctorate-level description of “Ions and action potentials”. Add to this your manual or e-learning that gives you just a few sentences with complicated phrasing.

The real question is, Do you need to know lots of depth and detail about action potentials for your level 3 anatomy and physiology exam?

The answer is NO.

You do, however… need to know what an action potential is?

and how it works as part of the nervous system?

You don’t need to know about all of the complex ‘Ins & Outs” and in today’s video, I’ll simplify this anatomy topic and make sure you understand how it all works.

At the end of the blog try the 3mock questions to test your knowledge on what you’ve learned.

What is an Action Potential?

An action potential is a wave of electrical activity that pulses along any electrically excitable cells (including muscles and nerves)

Watch this video to learn how information is moved throughout our body via our nervous system, and help you understand what is an Action Potential?

What is the role of the Nervous system?

The nervous system’s main function is communication. It transports information from one end of the body to another using both electrical and chemical signals.

Imagine you are on a train journey from the very northern tip of Scotland, to the Southern tip of Cornwall. It is not just one long train, there are lots of stops, and changes to get to your destination.

Imagine for a moment that every train journey you get is the Electrical Signal that runs through Neurons (nerve cells).

and when you reach the platform, you need to walk across the platform to take your connecting train. The walking across the platform is like the Chemical Signal that occurs when neurotransmitters pass between neurons.

Within each Neuron the “pulse has to be moved from one end to the other, it takes this route:

  • Dendrites
  • Nucleus
  • Axon (the electrical signal -the train journey)
  • Terminal
  • Neurotransmitters ( the chemical signal – walking between platforms)

What are Neurotransmitters?

These are chemical messengers that include Acetylcholine, Dopamine, and Serotonin (amongst many others). They are released from the synapse at the Axon Terminal and travel to the next neuron or muscle.

If going to a neuron the process restarts when the signal is collected at the dendrites.

If it is traveling to a muscle, it connects to the muscle membrane and stimulates an action potential which causes the muscle to contract via the sliding filament theory.

What is an Action Potential throughout the Axon?

An Action Potential is a complex and in-depth journey of “depolarising ions”. There are lots of complex examples and descriptions available, so let’s keep it simple here in preparation for your level 3 anatomy and physiology exam.

The Ions are essentially Positively and Negatively charged, which is like a light switch that can only turn on or off. They appear in sections along the length of the axon, when one changes from being positive to being negative, it makes the one next to it change.

And then like a wave (or pulse) the signal is sent all the way down the axon until it reaches the Axon Terminal and signals for the neurotransmitters to be released.

Test your knowledge with today’s Nervous system mock questions:

[NOTE: The answers are below the 3rd questions]

Q1: Which part of a neuron passes information via a chemical signal?

A. The length of the Axon
B. Nucleus
C. Neurotransmitters
D. Sarcoplasmic Reticulum

Q2: The process of Action Potential occurs in which part of the nervous system?

A. The length of the Axon
B. Nucleus
C. Neurotransmitters
D. Sarcoplasmic Reticulum

Q3: Which of the following is a neurotransmitter?
A. Sodium
B. Dopamine
C. Potassium
D. Calcium

Answers to the mock questions are :

Question 1= C, Question 2 = A, Question 3 = B

If you want more mock questions like this, then you can download more Free Mock Questions: DOWNLOAD NOW

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Hayley “What is an Action Potential” Bergman

Parallel Coaching

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