The brain is a complex and indispensable organ. In general, we know that the parts of the brain regulate the different actions of the organism, as well as our emotions, reasoning, memories, and so on.
We usually forget some of its functions since they are not part of our routine (unless we are neurologists or researchers specialized in this organ). To make things easier for you, we will review the brain’s structure and what function each of its parts has.
We don’t usually overlook the fact that there are many neurons in the brain, nerve cells that receive, process, and transmit information through bioelectrical impulses. On the other hand, it is considered that there are more doubts than certainties regarding its total capacity. For this reason, researchers are currently continuing their studies on this organ and its scope. Fascinating, right?
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The brain, an essential organ
The brain is a very complex organ that weighs around 1.5 kilograms. Now, so that its weight does not imply difficulty in movement or how people live, the brain floats in the cerebrospinal fluid inside a bone structure, better known as the skull.
The brain comprises 78% water, 10% fat, and 8% protein. According to research in the journal Neurology, this accounts for only 2% of body weight but uses the same amount of energy as resting skeletal muscle.
The brain is part of the central nervous system and is included within an anatomical region called the encephalon. It is common to confuse this region with the brain. However, the brain comprises various structures, such as the following.
1. Brain stem
The brain stem is located at the base of the skull. It controls vital functions such as heart rate, digestion, breathing, and blood pressure. Furthermore, it connects the brain to the spinal cord, thus carrying impulses to the rest of the body. The brain stem is divided into the medulla oblongata, the pons, and the midbrain.
2. Cerebellum
This organ is located in its posterior part at the base of the skull. The cerebellum maintains balance and posture and is involved in the entire body’s movement. Also, it is responsible for activities to be coordinated and precise.
3. Brain
The brain has many parts related to the senses, emotions, memories, and reactions. In short, it is the boss of our body. It is responsible for receiving, processing, and responding to different stimuli. For example: when trying to grab an object, the brain gets the signal from the sense of sight. In turn, it sends inspiration to the muscles of the arm and hand to approach the identified object and thus take it.
Brain development
The brain and all its parts go through gradual growth in the womb. In this sense, the organ goes through 3 different stages before birth, which will give rise to other parts:
- Rhombencephalonis is the least evolved part of the brain and one of the oldest. It is present in all vertebrate animals and transforms in the cerebellum and brain stem.
- Mesencephalon: originates all the middle parts of the brain, as well as the structures that connect both cerebral hemispheres.
- Prosencephalon: It is the most evolved part of the brain and is divided into two other fundamental sections, the diencephalon and the telencephalon.
The first of the parts of the forebrain mentioned, the diencephalon, will give rise to areas such as the thalamus and the hypothalamus. The telencephalon will generate the most superficial regions, such as the cerebral cortex, the basal ganglia, the limbic system, and the hippocampus.
Although its development begins in the embryonic stage, a StatPearls publication suggests it does not fully develop until 25 years later. The brain fully matures during young adulthood and begins a slow, progressive decline. If we are stricter, the fall starts sooner; gray matter in the temporal lobe regresses somewhat after age 18, according to a Progress in Neurobiology study.
How is the brain divided?
Researchers have divided the brain into different parts for years to facilitate their study. Each of these macroscopic regions is associated with specific functions in the organism, so all of them are essential.
1. Left and right hemispheres
First, the brain is divided into two cerebral hemispheres, the left, and the right, divided into four lobes.
According to a study in the Arquivo de Neuro-psiquiatria journal, the right side is related to non-verbal expression. For example, intuition or recognition of faces, voices, melodies, etc. In this hemisphere, thoughts and memories are manifested through images.
If the left hemisphere is impaired, the person will struggle to speak and write. As well as to express and understand other people, since the main components of language are located at this level, according to a study in the Journal of the Clinical Hospital of the University of Chile. Other functions are analytical skills, logical reasoning, solving numerical problems, etc.
However, today it is considered that both hemispheres work together so that many of the functions are performed by both. Both hemispheres are connected through a structure called the corpus callosum, which is responsible for transmitting impulses between them.
The right hemisphere is in charge of controlling the left side of the body, while the left hemisphere controls the right side of the body. Again, this is a general thing; since a PLoS biology publication describes that both hemispheres work together and not as isolated entities.
2. Brain lobes
Each hemisphere is divided into four lobes. As a StatPearls publication points out, each of them fulfills specific functions.
Frontal lobe
It is in the anterior area, in front of the Rolando fissure. It allows the execution of executive functions: attention, planning, sequencing, and reorientation. Conscious thought is processed in it; somehow, it is here that problems are solved. Also, it is related to personality and behavior. A small section of this lobe also controls some movements.
Parietal lobe
The parietal lobe is located at the level of the parietal bone. This is responsible for the perception of stimuli related to touch, pressure, taste, temperature, and pain, according to experts from the Repertoire of Medicine and Surgery. In the same way, it controls voluntary movements and balance.
Temporal lobe
It is located below and behind the temples on both sides of the skull. This part of the brain allows the decoding of auditory stimuli, which helps to understand speech, language, and music. In addition, it regulates the emotions of anger, anxiety, and pleasure.
Occipital lobe
It is the minor lobe of the cerebral cortex and is in the posterior part of the cerebral hemispheres. Its primary function is to process visual stimuli. In the same way, it allows us to carry out spatial recognition and discriminate colors and movement.
The cerebral cortex and its functions
The cerebral cortex also called the cortex, is the brain’s outermost layer. It is a thin, gray sheet that covers the entire surface of the cerebral hemispheres and lobes.
According to a publication in the Journal of Neurology, up to 80% of the total brain volume corresponds to cerebral certainty. This contains 20% of all neurons and, in addition, 60 million cells that are not neurons.
The primary function of the cortex is to integrate the stimuli received from deep structures to carry out complex mental processes. This part of the brain has three main components: the archicortex, the paleocortex, and the neocortex.
The archicortex is the oldest part and develops primitive functions like like like memory and emotions. The paleocortex was the next to evolve in living beings and comprised the termination areas of the olfactory pathways. The paleocortex carries out pre-rational activities associated with intuition and impulse in humans.
On the other hand, the neocortex is the most evolved part of the cerebral cortex. It is in charge of the processes of reasoning and consciousness.
Other essential parts of the brain
Functioning as the integrating center of all stimuli, the brain must have different parts that help it fulfill all its functions. Among the main structures of the brain, the following stand out:
- Basal ganglia: are structures located below the cerebral cortex, composed of the caudate nucleus, the putamen, and the globus pallidus. The basal ganglia are related to automatically performing previously learned complex movements, such as writing, speaking, or walking.
- Insula: It is located in the deep zone of the lateral surface of the brain. The insula is believed to be related to complex emotions such as love, hate, and sadness. It also plays a vital role in the sensation of pain, conscious desires, and addictions.
- Hippocampus: An ancient structure with an elongated shape is located inside the middle zone of the temporal lobe. It plays a fundamental role in forming new memories, spatial orientation, and acquiring new motor learning.
- Thalamus – This structure is the first integrating center of the brain. It is responsible for interpreting all external stimuli captured by the sense organs before sending them to higher brain structures.
- Hypothalamus: The primary function of the hypothalamus is to maintain the body’s homeostasis, as it is one of the main structures involved in the secretion of hormones. It also coordinates functions such as thirst, sleep, hunger, and other primitive instincts.
- Amygdala: They are nuclei of neurons located in the deep zone of the temporal lobes. This is integrated into the limbic system and generally regulates the functions of emotional memory and memory consolidation. In turn, it controls self-preservation responses in the food, sexual and aggressive spheres.
In conclusion
The brain, together with all its parts, is a mighty and complex organ. It controls all aspects of our lives, including many we are unaware of. In addition, it intervenes in the voluntary movements of our muscles, which we want to carry out. And although there is still a lot of uncertainty about the functioning of this organ, new data may be found thanks to the scientific investigations that continue to be developed.