What is the Definition of Brain?


From the Latin cerebrum, the brain is one of the nerve centers that make up the brain. It is located in the upper and anterior part of the cranial cavity and appears in all vertebrates.

In humans, the brain weighs between 1.3 and 1.6 kilos. The cerebral cortex (that is, the surface of the brain) houses about 22,000 million neurons, according to what is expressed in the most recognized medical studies.

Cellular metabolism generates the biochemical energy that the brain uses to trigger neuronal reactions. The energy is received by the dendrites and emitted in the axons in the form of molecules of chemical substances that are called neurotransmitters.

The brain is the organ in charge of controlling and coordinating all the movements that we make and of processing sensory information. On the other hand, it is dedicated to regulating homeostatic functions, such as blood pressure, body temperature and heartbeat.

Ultimately, the brain is responsible for learning, cognition, memory and emotions. Its operation is carried out through the interaction between its different areas.

The brain is divided by a longitudinal fissure that makes it possible to distinguish between two cerebral hemispheres: the right and the left. In turn, each hemisphere has other fissures, but not so deep, that divide the cerebral cortex into different lobes.

Although both hemispheres are opposite, from a morphological aspect they are not symmetrical. On the other hand, it should be noted that only humans seem to show a difference in competencies between the two hemispheres. By the way, the functions and characteristics of each are detailed below, according to the studies known so far.

The left hemisphere is responsible for the recognition of writing and the coherence between the different words that make up a sentence, as well as the understanding of speech, numbers and mathematical and logical operations, and even the abstraction necessary to express ideas of oral or gestural form. This region of our brain is considered as the origin of our expressive capacity, and an injury that affects it can generate terrible disorders in its functions, such as speech and mobility of the right half of our body, although the seriousness of the consequences it directly depends on the type of damage suffered.

Although science has not been able to decipher the mechanisms that the brain uses to start from a certain group of ideas, which have been converted into words, relate them to each other and finally build a more complex sentence or idea, it is believed that before assigning a word to a concept, the mind tries to understand it independently; that is why we are able to learn different languages, and to look at knowledge from various cultural perspectives. It is worth mentioning that intelligence tests focus mainly on the performance of the left hemisphere, since most of its functions are related to consciousness, analysis and measurement, accuracy and expressiveness.

The right hemisphere, in a complementary manner, has in its power the integration of visual and sound information, to collaborate with orientation in space and understand the world through feelings and sensations; works in a way almost opposite to the left, trying to unite the concepts in a whole, instead of dividing them into small portions. This hemisphere is considered the most active in people with skills for art in general. A very interesting example explains that if we unexpectedly meet someone we know, it is precisely this region that performs the relevant facial recognition, although it requires subsequent work on the left hemisphere to find their name and other personal data in our memory.