Difference Between Axon and Dendrite

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Human Nervous System 

The human nervous system is divided into two components- the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS is the hub or center of an organism’s body that includes parts of the brain and the spinal cord. This system regulates the information, command, coordination, and integration that influences the various activities within the body. The other component of the human nervous system is the PNS. It consists of neurons and other parts outside the CNS. The signals received by the CNS are mainly from the PNS that plays a supporting role. 

Neurons are components of the PNS that are fundamental for processing and transferring information to nerve cells, muscles, and glands. There are several billions of neurons present in our body having extensions like axons and dendrites. 


What are Neurons?

Neurons are the nerve cells having a cell body known as soma. Neurons produce a good amount of protein, and these neuronal proteins are absorbed in the soma. These nerve cells have two vital and distinctive components within them, which are called the axon and dendrites. The short branching processes are known as dendrites, while the ones that are longer than the dendrites are known as axons. This is the main structural difference between dendrites and axons. 

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What are Dendrites? 

Dendrites are the specialized short fibrous branches that extend from the nerve cell body. The dendron’s function of accepting and process incoming information takes place within the dendrites. These incoming signals of a dendron function are of two categories- excitatory that makes the neuron take the trigger and inhibitory that prevents the neuron from taking the trigger. A single neuron may consist of more than one set of dendrites and can receive plenty of information from the input signals. It is up to the neuron whether it will get excited and take a trigger or not. This impulse is mainly dependent upon the total number of excitatory and inhibitory signals it gets. If the neuron rejects the trigger, the nerve impulse is taken down to the axon. 


What are Axons?

If you understood what are dendrites, it is time to understand the concept of the axon. The axon is a long tail-like projection of the nerve cell, also known as nerve fiber that conducts the electrical impulses in the body away from the nerve cells or soma. These typically arise from the cell body at a special junction called axion hillock. The axons are the primary transition lines that bundle up to create the nerve. The difference between axon and dendrite is a fatty substance called myelin that is found to cover only the axon. The axons split up at the end and develop bulbous swellings called axon terminals which get connected with the target cells. 


What are Synapses? 

A single neuron or a nerve cell has immense potential to carry out various activities. An individual neuron receives its signals from the dendrites and cell bodies and carries it down to the axon terminal. The difference between dendrites and axons is that the former is the receptor while the latter is the transmitter. When neuron to neuron connections are made at a site, it is known as synapses. The information in a neuron is carried from the first neuron called the presynaptic neuron to the target neuron called the postsynaptic neuron. 


What Is the Difference Between Axon and Dendron?

Let us take a look at the factors that shows the difference between axon and dendron.

Difference 

Axon 

Dendron 

Place of origin

It originates from the discharging end of the neuron.

It originates from the receiving end of the neuron. 

Number

There is only one axon for a single nerve cell. 

There are several dendrites present in a nerve cell. 

Length

It is a long tail-tail structure. 

It is a short fibrous roots-like structure. 

Thickness

It has a uniform thickness throughout the length. 

It has a tapering end with root-like branches. 

Nissl’s Granules

The nissl’s granules are absent. 

The nissl’s granules are present. 

Synaptic Knots

The terminal branches of the axon develop an enlarged synaptic knot. 

There are no synaptic knots formed on the tip of dendrites. 

Direction of Conduction

It conducts neuronal impulses away from the soma. 

It conducts neuronal impulses towards the soma. 


Axons Vs Dendrites

In axon vs dendrites, we can see that both are important parts of the nervous systems. There are many differences between the two organs of the body but there are some similarities too. First, both are cytoplasmic projections of the cell body. Second, the nerve impulses are carried in axons and dendrites. 


Did You Know?

Some neurons do not have separate axons in their structure. In an anaxonic neuron, there is no anatomical difference between axon and dendrites. The anaxonic neuron is mainly of two types that are found in the human nervous system. First is the undifferentiated anaxonic neuron where the axon cannot be distinguished from the dendrites. The second one is the unipolar brush cell (UBC), which has only a dendritic arbour and is devoid of the axon. These nerve cells are mainly located in the retina and brain. 

FAQ (Frequently Asked Questions)

1. What Are the Different Types of Neurons?

There are mainly three different types of neurons found within the body. The sensory neuron, motor neuron, and interneurons. In the sensory neurons, the signals from the external environment are converted into internal stimuli. The sensory inputs are activated in the sensory neurons which get processed through body parts like the brain and spinal cord. The motor neurons are multipolar and are found in the central nervous system. The axons of motor neurons are extended outside the CNS. This neuron is responsible for transmitting the signal from the brain to the muscles of the body. The last is the interneurons which are multipolar in nature. The axons are mainly connected to the sensory and motor neurons. It conveys the signals between two neurons. 

2. What is a Nerve?

A nerve is a body cable that has been found to conduct nerve impulses and transmit information from one part of the body to another. A nerve is an integral unit of the peripheral nervous system. The primary function is to coordinate and control the operations within a body. A nerve is composed of a bundle of fiber structures enclosed with layers of tissue and fat that stretches throughout the body. The nerve receives information from the dendrites and transmits it through the axons to the respective body part. The nervous system not only communicates the message but also processes it into chemical signals to create impulses within the body.