What Is A Neuron
What Is A Neuron

What Is A Neuron: Definition, and 9 Parts and Its Functions

What Is A Neuron?

What is a neuron? Neurons (also called neurones or nerve cells), are the basic units of the brain and nervous system. It is the cell responsible for receiving sensory input from the outside world. For then, send motor commands to our muscles. And to change as well, deliver an electrical signal at every step between the two.

More than that, their interactions, determine who we are as human beings. Therefore, about 100 billion neurons interact closely with other cell types. Broadly, it is classified as glia (the number of these neurons, actually more than that, although not really known).

The process of forming new neurons in the brain, called neurogenesis. And, this can happen. Even in older persons.

What is a neuron definition?

Nerve cells or neurons are cells that deliver the “stimuli” impulses of the “five senses” receptors in the brain and vice versa. Nerve cells, commonly referred to as neurons, are also responsible for reflex motion. These neurons form a nervous system in humans.

Nerve cells are different from other cells in general because there is a “neurite” axon so that nerve cells look like they have a “tail”. Nerve cells consist of parts commonly found in animal cells and some other parts.

What is a neuron part and Function?

Neurons specialize in cell parts such as axons and dendrite that help them receive and send information. When part of the central nervous system (CNS) suffers severe injuries, it cannot produce new neurons or regenerate new axons of damaged neurons. There is no treatment that can help restore nerve function after an injury to the CNS.

The central nervous system consists of the brain and spinal cord, while the peripheral nervous system “PNS” consists of nerves that help connect the CNS to each and every part of the body. A neuron is a special cell capable of transferring electrochemical impulses called nerve impulses. In most cases, neurons are produced by a special type of stem cell.

They do not experience cell division, for the body cell diameter of neurons can vary from 4 to 100 micrometers. To be able to understand the different types and functions of neurons it is necessary to be able to know its structure. Well, here are the parts of neurons and their functions.


Dendrite is a branch of the body of nerve cells in the form of short, branched cytoplasmic protrusions. The function of the dendrite is to receive and deliver stimuli to the body of cells.

Cell Body

The body of the cell is a major part of nerve cells containing parts that are commonly owned by animal cells. In the body of the cell there are the cytoplasm, the nucleus (cell nucleus) and the nucleoli (the cell nucleus child). The function of the cell body is to receive impulses (stimuli) from the dendrite and pass it to the neurite (axon).

Cell Nucleus

The nucleus of the cell is the nucleus of nerve cells that serves as a regulator of the activity of nerve cells (neurons). In the nucleus of the cell there are also chromosomes and DNA that serve to regulate the hereditary properties of the cell.


Neurite is a long nerve cell fiber that is the cytoplasm of the body of the cell. Neurite is also called axons. Neurite is similar to dendrite, but there is only one neurite and is larger and longer than dendrite. Inside the neurites are fine threads called neurofibril.

Axons play a role in delivering impulses from the body of cells, leading to the effector, such as muscles and glands. Although the diameter of the axon is only a few micrometers, it can reach 1 to 2 meters in length. The function of neurite is to pass impulses from the body of nerve cells to other nerve cells.

Myelin Sheath

The Myelin sheath is neurite wrapping membrane, myelin sheath contains a lot of fat and segments. The indent between the two segments is called Ranvier nodes. The myelin sheath is surrounded by Schwann cells. Cells that produce myelin sheaths are called glial cells or oligodendrocytes.

The function of the myelin sheath is to protect neurite from damage and prevent leaking impulses. The function of the myelin sheath is similar to the electrical cable wrapper that is insulator.

Schwann Cell

Schwann cells are cells that surround the myelin sheath. The cell was discovered by Theodore Schwann, a scientist from Germany. Schwann cells work by producing fat and wrapping neurite many times until a myelin sheath form. The function of Schwann cells is to accelerate the path of impulses, which helps provide food for neurite and helps the regeneration of neurite.

Ranvier Nodes

Ranvier nodes are a part of the neurite that is not encased in a myelin sheath. The myelin sheath serves as an axon protector and wraps it, but the sheath does not wrap in its entirety and the unwrapped one is Ranvier nodes. Its main function is as a springboard to be able to accelerate nerve impulses to the brain or vice versa.

Ranvier nodes were about 1 micrometer in diameter and were discovered by Louis-Antoine Ranvier. The presence of Ranvier nodes allows the nerve to jump from one node to another, so that the impulses reach the destination faster. If Ranvier nodes is shrouded by a myelin sheath then the nerve impulses can not jump into Ranvier nodes, eventually no response whatsoever.


Oligodendrocytes are a supporting cell that provides isolation of nerve cells by forming a myelin sheath around the axon. The function of oligodendrocytes is to form the same myelin sheath in the central nervous system and as a supporting cell. Oligodendrocytes have several elongated projections that each wrap (like a roll omelette) a piece of the axon between neurons to form a myelin segment.


Synapses are meeting points between the axon terminal of one neuron and another. In each neuron, its axon terminal swells to form a small bulge called a synaptic bouton. In each synapse, there is a synaptic gap, a connection between neurons that allows sensory information to flow between them.

At the end of the axon, there is a bag called axon bulb. The bag contains a chemical called a neurotransmitter. Neurotransmitters can be acetylcholine and cholinesterase that function in the delivery of nerve impulses in synapses. The function of synapses is to transmit impulses from axons to dendrite in other nerve cells.

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What Is A Neuron: Definition, and 9 Parts and Its Functions

Post in | Last updated: January 29th, 2021 |