What is our brain like and how does it work?
The brain is, without a doubt, the most complex organ in our body and is involved in all the functions and tasks that we carry out every day and that keep us alive. And it is that it not only helps us to think, reason or speak; also for things as basic as breathing or blinking, as well as to dream and get excited. This article analyzes what our brain is like and how it works.
How does our brain work?
Through the senses, the brain receives an enormous flow of information from the world around us, processes it and makes it meaningful, organizes and controls movement. In addition, the functions of the brain also include those of regulating body temperature, blood circulation, respiration and digestion.
An adult brain weighs between 1,300 and 1,400 grams. It contains about 100,000 million neurons and a much larger number of synapses, which allow the connection between neurons. When we make decisions and experience emotions, a complicated mix of chemical and electrical processes takes place in the brain.
Parts of the brain The brain is part of the brain
The brain consists of three large areas: the brain itself, the cerebellum, and the brain stem.
The cortex or cerebral cortex is the outer surface of the brain and has a large area, approximately equivalent to between one and two sheets of newspaper. It is contained in the skull thanks to numerous folds and crevices. Only a third of the crust is superficially exposed, the rest is hidden deep in the furrows. In this way, the space is used much better than if the cortex were smooth and allows different regions of the brain to communicate more quickly and easily, since they are closer together.
The cortex is part of what is known as gray matter, which is a component of brain tissue that is mainly made up of the bodies of neurons. Below the cortex we find the white matter, formed by nerve extensions covered with myelin (an insulating substance that gives them the white color) that transmit information to the different regions of the brain (as cables that connect different neurons so that they can communicate with each other ).
The brain is divided into two large parts, the right and left hemispheres, which are connected to each other by a set of fibers, which constitute the corpus callosum. Each of the hemispheres has four lobes: frontal, parietal, temporal and occipital. And each lobe contributes differently to different brain functions.
For example, roughly:
The occipital lobe is essential for processing visual information.
The parietal, among other things, is key in the integration of different types of sensory information to guide our movements.
The temporal helps us to give meaning to sensory, auditory and visual information, and allows many processes related to language. In this lobe is the hippocampus, which plays a crucial role in learning and memory and is affected by the first neuropathological alterations of Alzheimer’s disease.
And finally, the frontal acts as a conductor to plan and execute our acts based on the information it receives from different brain regions and also participates in the production of language.
In addition, in the deepest part of the hemispheres, we find various nuclei of neuronal bodies with specific functions that, like the cortex, are also part of the gray matter. Some of the most important are the basal ganglia and the thalamus, which, among other things, participate in functions related to the processing of sensory and motor information.
The cerebellum, located at the back and bottom of the skull, plays a key role in maintaining balance and in the coordination and precision of movements.
At the base of the skull is the brain stem, which connects the brain to the spinal cord and controls automatic bodily actions such as heart rate, blood pressure, and respiration, as well as voluntary movement of the eyes, tongue, and muscles. of the face, among others.
The brain is part of the central nervous system
The central nervous system has, in addition to the brain, other fundamental parts, such as the spinal cord, which communicates the brain with the rest of the body, transferring nerve impulses from different areas of the body and sending signals and orders from the brain to different regions of the body. .
On many occasions, however, the spinal cord produces a performance by itself, without the information ever being transmitted to the brain. It is what we know as reflections. For example, when we quickly withdraw our hand from the fire so as not to burn ourselves, the spinal cord acts in this emergency situation, in a reflex way.
Communication between neurons: what are synapses?
Neurons or nerve cells are the fundamental units of the brain and nervous system. They are responsible for the reception of sensory inputs from the outside world, as well as for sending orders to different parts of the body and for transforming and transmitting the electrical signals that allow it.
They have different shapes and sizes, but they all consist of three elementary parts: the cell body or soma, the axon and the dendrites:
In the cell body is the nucleus (which contains DNA) and is where proteins are formed.
The axon is a wire-like part of the cell that carries electrochemical messages.
The dendrites or nerve branches are short projections of the cell, like branches, that establish connections with other cells. Dendrites receive messages through neurotransmitters released by axons from other nerve cells. In the initial part of the axon of a neuron (where it joins the neuronal body) an action potential is generated, a short electrical impulse that travels along the axon and causes the release of neurotransmitters (they are like messengers) at the synapse, the point where this release occurs and the reception of the message by another neuron, thus allowing communication between them.
The connection between neurons is essential for their own survival. They need cooperation with other neurons to develop their function and the support of other types of cells to stay healthy and active.
In addition to neurons, nervous tissue contains other types of cells that form the so-called neuroglia, whose function is to support nerve cells, provide them with the necessary nutrients for their proper functioning and defend the nervous tissue from viruses or other microorganisms.
To prevent their own death, neurons, with the help of neuroglia, have to be constantly maintained and remodeled. If cell cleaning and repair slows down or stops for any reason, the neuron cannot function properly and ends up dying.
Knowing better how the brain works will help to better understand neurodegenerative diseases, such as Alzheimer’s and other causes of dementia.