HomeTren&dThe Neuron: A Labelled Diagram and Its Functions

The Neuron: A Labelled Diagram and Its Functions




Understanding the structure and functions of a neuron is crucial in comprehending the complex workings of the human brain. Neurons are the building blocks of the nervous system, responsible for transmitting electrical and chemical signals throughout the body. In this article, we will explore the anatomy of a neuron, its various components, and how they work together to facilitate communication within the brain.

The Anatomy of a Neuron

A neuron consists of three main parts: the cell body, dendrites, and axon. Each component plays a vital role in the transmission of signals.

The Cell Body

The cell body, also known as the soma, is the central part of the neuron. It contains the nucleus, which houses the genetic material and controls the cell’s activities. The cell body is responsible for maintaining the overall health and functioning of the neuron.


Dendrites are branch-like structures that extend from the cell body. They receive incoming signals from other neurons and transmit them towards the cell body. These signals, known as synaptic inputs, can be either excitatory or inhibitory, depending on their effect on the receiving neuron.


The axon is a long, slender projection that extends from the cell body. It carries electrical impulses away from the cell body and transmits them to other neurons or target cells. The axon is covered by a myelin sheath, which acts as an insulating layer and speeds up the transmission of signals.

Types of Neurons

There are three main types of neurons: sensory neurons, motor neurons, and interneurons. Each type serves a specific function in the nervous system.

Sensory Neurons

Sensory neurons, also known as afferent neurons, transmit sensory information from the body’s sensory organs to the central nervous system. For example, when you touch a hot surface, sensory neurons in your skin send signals to your brain, allowing you to perceive the sensation of heat.

Motor Neurons

Motor neurons, also known as efferent neurons, transmit signals from the central nervous system to the body’s muscles and glands. These neurons are responsible for controlling voluntary movements and regulating bodily functions. For instance, when you decide to move your hand, motor neurons carry the signals from your brain to the muscles in your hand, enabling the desired movement.


Interneurons, also known as association neurons, are located within the central nervous system and facilitate communication between sensory and motor neurons. They integrate and interpret incoming signals, allowing for complex processing and coordination of information. Interneurons play a crucial role in decision-making, memory formation, and other higher-order cognitive functions.

How Neurons Communicate

Neurons communicate with each other through a process called synaptic transmission. This process involves the release of chemical messengers, known as neurotransmitters, from the axon terminal of one neuron to the dendrites of another.


A synapse is a small gap between the axon terminal of one neuron and the dendrites of another. It is at the synapse that the transmission of signals occurs. The presynaptic neuron releases neurotransmitters into the synapse, which then bind to receptors on the postsynaptic neuron, initiating a response.


Neurotransmitters are chemical substances that transmit signals across synapses. They are stored in vesicles within the axon terminal and are released when an electrical impulse reaches the terminal. Some common neurotransmitters include dopamine, serotonin, and acetylcholine, each with its own specific functions and effects on the receiving neuron.

Excitatory and Inhibitory Signals

Neurotransmitters can have either excitatory or inhibitory effects on the receiving neuron. Excitatory signals increase the likelihood of the receiving neuron firing an action potential, while inhibitory signals decrease this likelihood. The balance between excitatory and inhibitory inputs determines whether a neuron will transmit a signal to other neurons.

Common Neuronal Disorders

Disruptions in the structure or functioning of neurons can lead to various neurological disorders. Understanding these disorders is crucial for developing effective treatments and interventions.

Alzheimer’s Disease

Alzheimer’s disease is a progressive neurodegenerative disorder characterized by memory loss, cognitive decline, and behavioral changes. It is associated with the accumulation of abnormal proteins in the brain, leading to the death of neurons and the formation of plaques and tangles.

Parkinson’s Disease

Parkinson’s disease is a neurodegenerative disorder that affects movement and coordination. It is caused by the loss of dopamine-producing neurons in a specific region of the brain called the substantia nigra. This loss of neurons leads to the characteristic motor symptoms of Parkinson’s disease, such as tremors, rigidity, and bradykinesia.


Schizophrenia is a chronic mental disorder characterized by disturbances in perception, thought, and behavior. While the exact cause of schizophrenia is unknown, it is believed to involve a combination of genetic, environmental, and neurochemical factors. Studies have shown abnormalities in the structure and functioning of neurons in individuals with schizophrenia.


Neurons are the fundamental units of the nervous system, responsible for transmitting signals and facilitating communication within the brain. Understanding the structure and functions of neurons is essential in comprehending the complexities of the human brain and the various neurological disorders that can arise. By studying neurons, researchers and healthcare professionals can develop effective treatments and interventions to improve the lives of individuals affected by these disorders.


1. What is the main function of a neuron?

A neuron’s main function is to transmit electrical and chemical signals throughout the body, facilitating communication within the nervous system.

2. What are the three main parts of a neuron?

The three main parts of a neuron are the cell body, dendrites, and axon.

3. What is the role of neurotransmitters in neuronal communication?

Neurotransmitters are chemical substances that transmit signals across synapses. They play a crucial role in facilitating communication between neurons.

4. What are the different types of neurons?

The different types of neurons are sensory neurons, motor neurons, and interneurons.

5. What are some common neuronal disorders?

Some common neuronal disorders include Alzheimer’s disease, Parkinson’s disease, and schizophrenia.

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