Gayathri Mani

Neuron Study Guide

A neuron is the most basic form of nerves and the brain. It is responsible for carrying messages to and from all parts of an organism’s body.


We wrack our brains and bombard them with tasks and information every day. From the song you’ve heard over a hundred times a day to the latest video from your favorite YouTube channel, our brain handles a multitude of tasks daily.

Our brain also does important tasks like regulating breathing and telling exactly how fast our legs should move while running. But, have you ever stopped to wonder how all this happens?

Well, miraculous cells called neurons are responsible for all this. These tiny entities not only cluster together to enable us to think, but they also carry the brain’s instructions to where they are supposed to go.

What is a Neuron?

Neurons are defined as the fundamental units of the brain and nervous system. They are responsible for receiving sensory input, sending motor commands to our muscles, and transforming and relaying the electrical signals at every step in between.

Neuron Anatomy

There are 3 main parts of a neuron: the cell body, dendrites, and axons.

Structure-Neuron Source

Functions of Neurons

Parts-of-a-Neuron-Diagram Source

  • The most fundamental function of neurons is to transmit signals from your brain to the intended recipient: muscles and glands.

  • They do this by a process called nerve impulse, in which neurons transmit electrical and chemical signals to other cells.

  • They receive and pass on these signals via rootlike extensions known as dendrites.

  • Neurons send signals from the dendrite to an axon by changing their electrical potential.

  • This is achieved by the release of sodium and potassium ions.

  • Messages are relayed through synapses chemically by neurotransmitters who attach themselves to the dendrites of the receiving dendrite.

What is a Neuron Cell Body?

  • The neuron cell body is known as soma. It is the central part of the cell and houses the nucleus and other organelles.
  • The other part of the neuron, dendrites, and axons, connect directly to the cell body.
  • It stores genetic information, sustains the activities of the neurons by providing energy, and preserves the cell’s shape.

What are Dendrites?

  • Dendrites are branched extensions at the beginning of a neuron that serves as the site for neurotransmitters to attach to.
  • Their shape inherently creates a large surface area, helping them function more efficiently.
  • Each cell has thousands of Dendrites to help increase inter-connectivity with neurons and facilitate faster message transmission.

What are Axons?

  • Also called nerve fibers, axons are the long structures that take impulses away from the cell body and pass them on to other cells.
  • Each Neuron has only one axon to receive messages from thousands of dendrites.


  • These tiny cells help in regulating the activities of the brain.
  • Without them, we are just a bag of blood, bones, and muscles hung on a frame we call our skeleton.
  • Their complex but efficient methods of transmission and thinking have enabled us to differentiate Homo sapiens from the rest of the jungle.


1. What is a neuron and its function?

A neuron is a nerve cell that carries electrical impulse signals to and from the brain. It is the most fundamental unit of the nervous system. Neurons are also called nerve cells. They are tiny cells that facilitate the transfer of information all over the body. Neurons can survive forever. Their life cycle is dependent on the host body’s life span.

2. What are the three types of neurons?

Sensory, motor, and interneurons.

  • Sensory neurons: Neurons activate by sensory input. They send stimulus information to the brain.
  • Motor neurons: They connect to muscles, glands, and organs, directly controlling all our muscle movements.
  • Interneurons enable communications between the sensory and motors neurons and the Central nervous system.

3. What is a neuron in simple terms?

If you take a nerve or a brain and start cutting it into smaller and smaller pieces, the smallest working unit you will find is a neuron.

4. Where is the neuron located?

Neurons are found in the nerves, brain, and spinal cord.

5. How do brain cells work?

Neurons produce electrical potentials by regulating K and Na ions, called action potentials or nerve impulses. These impulses allow neurons to communicate with each other, understand information, control involuntary actions, and pass messages all over the body.

6. What is the difference between neurons and nerves?

Neurons are defined as the most fundamental unit of nerves. Every nerve consists of billions of neurons working together.

7. How do nerves work?

When an impulse reaches the end of the axon, it releases neurotransmitters- chemicals that carry the impulse across the synapse. Neurotransmitters cross the synapse and reach the dendrite of the next Neuron. They then bind to the dendrite, allowing the impulse to travel through the receiving Neuron. This process is like how dominos fall. Once the first domino falls on another domino, a chain reaction is instigated- leading to every domino falling one by one. Impulses travel like dominos fall, passing from one Neuron to the next.

8. How are neurons connected?

Neurons are separated by tiny gaps called synapses. Neurons pass information to each other by chemicals called neurotransmitters.

9. What is in the brain?

Weighing about 1.5 kg in the average adult, the brain is about 60% fat; the remaining 40% is a combination of water, carbohydrates, and proteins.

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  1. Neurons and Their Role in the Nervous System. https://www.verywellmind.com/what-is-a-neuron-2794890. Accessed 25 Nov, 2021.
  2. Neuron. https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/13.13/primary/lesson/nerve-cells-bio/. Accessed 25 Nov, 2021.
  3. All you need to know about neurons. https://www.medicalnewstoday.com/articles/320289. Accessed 25 Nov, 2021.
  4. The Neuron. https://flexbooks.ck12.org/cbook/ck-12-biology-flexbook-2.0/section/13.13/related/lecture/the-neuron/. Accessed 25 Nov, 2021.