Neurons are the cells that make up the nervous system. They are highly specialized and serve the function of transmitting information throughout the agency. They do so through electrical impulses: a true wonder of nature.
Because of neurons, it is possible to perform several of the basic functions of intelligent life. They play a fundamental role in movement, perception, and reasoning. For this, they use a very specialized structure, which we will talk about below.
Parts of Neurons and Their Characteristics
Neurons are the functional and structural unit of the entire nervous system. They are composed of different parts and each of them has specific characteristics and performs very specific functions. Let’s see what those parts of the neuron are.
- Soma or cell body
It can be said that the soma or cell body is the control panel or a control center of the neurons. It is the widest area and houses the cytoplasm and nucleus. It has an oval shape. There’s also all the genetic material in this cell.
The soma performs the necessary processes for the neuron to remain alive so that it can fulfill its function of transmitting electrical signals properly to other neurons.
- Dendrites
Dendrites are small prolongations that are born of the body or some. Together they form a kind of network that covers the entire center of the neuron. What they do is capture the chemical signals sent to them by the neuron that precedes them.
After this, the dendrites send that information to the neuron’s body. This makes the cell electrically activated. In short, they receive chemical information and transmit it to become electrical signals.
- Axon
An axon is an extension, like a kind of tail, that comes out of the body of the neuron. Its length varies, depending on the area of the body in which you are located. It is located at the opposite end of the dendrites. Its function is to take the electrical impulse and drive it to another area called the synaptic button.
- Core
The nucleus of neurons is the structure that contains the DNA of these, that is, the genetic information of the cell. Therefore, from there control is exercised over everything that happens in the neuron. In general, it produces the energy the cell requires to be able to function.
- Myslin’s pod
Myelin is a layer that surrounds the axon of neurons. It is not continuous, but is present in pieces, with a separation between them that has no more than one micrometer in length. It is made up of proteins and fats, and its function is to allow the electric impulse to travel through the axon at the right speed.
- Substance of Nissl
It is also known as Nissl’s ducks. It corresponds to granules that are present in the soma of the neurons and the dendrites, but not in the axon. It is a real protein-producing factory. The latter is indispensable for the transmission of electrical impulses.
- Ranvier’s nods
Ranvier’s nodules are the areas of the axon that are not covered by the myelin pod. That is the spaces between one portion of myelin and the other. Through them, sodium and potassium enter the neurons. This helps the electric signal travel faster and more smoothly through the axon.
- Synaptic buttons
Synoptic buttons are branches that are at the bottom of the axon. These take the electrical signal that comes out of the axon; then, they emit chemical signals that must be captured by the dendrites of the next neuron. They are also known as the axon’s terminals.
- Anxonic cone
This area is morphological, but not functional. That is, it should be mentioned as a part of the neurons, but it does not have a specific role. It is the narrowest part of the neuron’s body and gives rise to the formation of the axon.
- Neuroglia
There are some components that, in the strict sense, are not part of the neuron. However, they are indispensable for their functioning. These components are other cells such as:
- Astrocito. It Nourishes, cleanses, and supports neurons.
- Oligodendrocyte. It covers the axons with myelin. Also, it gives support and unites the cell.
- Microgial. It removes waste, deals with the immune response, and helps maintain the balance of neurons.
- Schwann cells. It covers the axons of neurons in the peripheral nervous system with myelin.
- Ependimo little. It covers the cerebral ventricles and a part of the spinal cord.
Types of Neurons:
Not all neurons are the same. They differentiate each other by the role they play and, from that point of view, there are four types, as we will see below.
- Sensory Neurones
These are the neurons that receive the stimuli of the outer environment. Such stimuli can be perceived through the five senses: sight, smell, touch, taste, and hearing. They are also responsible for transmitting signals emitted by internal organs to the brain.
- Motor neuron
Motor neurons emit signals from the central nervous system to the muscles. Movement in the body occurs in response to these electrical impulses, according to the specific needs of each situation.
- Interneurons
This type of neuron is responsible for performing an intermediary function. What they do is transmit information between sensory neurons and motor neurons. They ensure that messages are transmitted and received in the right way.
- Neurons of relay
Relay neurons are large. They play the role of transmitting information from one part of the central nervous system to another area of the system, without the need to go through the peripheral nervous system.
How Does a Neuron Work?
Neurons function as an information highway through electrical signals that are transmitted from one cell to the other. The process is cyclical. When the information reaches the end of the axon, it passes to the synaptic buttons.
There, particles called neurotransmitters are released. Some of them are lost, but others enter the dendrites of the next neuron. When this happens, the dendrites transmit that signal to the neuron’s body. That activates the electrical signal, which will stop the axon to start the cycle again.
All this process always occurs between two neurons and is repeated to infinity. Whenever there is a stimulus, that chain process is repeated, at an impressive speed. This process is known as “synopsis.”
Neurons and Their Complex System of Connections
It is estimated that a single neuron can have between 5,000 and 200,000 synapses with other neurons. It is through a complex system of billions of neural connections that the brain can organize and process information all the time.
On the other hand, the human brain is believed to have between 67 and 87 billion neurons. Although the basic classification of these cells is of four types, as we explained before, up to 10,000 different types of neurons are spoken in other classifications.