Synonym
lat. cerebrum, Greek. Encephalon, English: BrainThe brain is the most important organ of vertebrates and forms the superior command center of the central nervous system.
It regulates all conscious and unconscious functions and processes. The brain is also the most highly developed organ of vertebrates, as its large number of networked neurons (19-23 billion in humans) enables it to process and evaluate complex information content and to adjust a physical reaction to this content (behavior). Last but not least the brain is able to store and recall experiences and memories.
The simplest processes of the central nervous system are connected in so-called reflex pathways. These have the advantage that they can process information relatively quickly and do not have to be perceived via the cerebral cortex. These include, for example, the regulation of heart rate, breathing, pupil reaction and, of course, the patellar tendon reflex, which is obligatory for reflex testing.
These reflexes form the basis of innate defensive reactions and enable the organism to adapt quickly to its environment. For example, if the light is too strong, the pupils are constricted to reduce the light incidence on the retina. Last but not least, the ability to learn and apply learned content, or to evaluate and apply it, is certainly one of the most important cognitive functions of the brain.
Biologically speaking, the brain is constantly changing and constantly forming new connections between nerve cells, so that, roughly speaking, at the end of the day we have a “different” brain than the one we woke up with. This means that with each new connection that is created between our nerve cells, a potential new information pathway is created through which new and old content can be processed. This ability to absorb, process and apply information makes the human brain the most complex organ we know.
The spectrum of brain functions thus ranges from simplified reflex programs (which every lower life form possesses) and innate behavior to highly developed cognitive processes such as thinking and learning. The human brain can be divided into 2 brain hemispheres. It weighs between 1245 and 1372 grams (in humans) and consists of almost 23 billion nerve cells and intercellular tissue.
The brain is covered by the skull (so-called neurocranium) and is separated from the so-called facial skull (viscerocranium). The brain floats in the cerebrospinal fluid, also called cerebrospinal fluid, which is formed by the plexus choroidei. It serves as a nourishing medium and as a protection against movements of the brain within the skull.
The brain is also surrounded by the meninges, which also have a protective and nutritional function. On the surface of the brain you can see the so-called Gyry and Sulci (coils and valleys). These enlarge the surface of the brain so that several nerve cells fit into the same space, namely the skull.
In this way, the performance of the brain could be increased without the skull having to grow along with it, to a large extent. The brain can be divided superficially into different lobes, some of which form neuroanatomical as well as functional boundaries. These include the frontal (frontal lobe), parietal (parietal lobe), occipital (occipital lobe) and temporal (temporal lobe).
In these lobe areas lie important functional centers of the central nervous system, such as the speech and sensory centers (parietal lobe), the hearing center and the seat of the primal drives and feelings (temporal lobe) and the visual center, which is located in the occipital lobe. The frontal lobe contains motor centers, higher cognitive centers (thinking, deciding), the seat of behavior and the urges (“origin of an idea”). The complex cooperation between these centers and the ability to think and plan as an individual distinguishes humans from other vertebrates.
These special abilities are of course also reflected in the rough anatomy of the brain of different vertebrates. The brains differ in size and shape and in many cases are also adapted to special tasks. For example, the olfactory and auditory centers are particularly pronounced in dogs and are many times more sensitive than the senses of humans. Every species, no matter how highly developed it is, must survive in nature through special abilities. These can also be of a physical nature.However, the further development of the senses, which ultimately enable communication with the environment, is an important process and ultimately part of natural evolution.