The term hemisphere It has its origin in the Latin word hemisphaerĭum, which in turn comes from a concept of Greek root. In the field of geography , it is used to describe the half of the Earth's surface , which is segmented by a maximum circle (such as Ecuador or a meridian).
In relation to the Ecuador line , it must be said that the planet can be divided into two parts: one known as northern hemisphere or northern hemisphere and another called southern hemisphere or southern hemisphere . For him Greenwich Meridian Instead, the Earth sphere adopts another division that is known under the names of eastern hemisphere and Western Hemisphere .
The northern hemisphere is where North America, part of South America, the Arctic, Europe, most of Asia, an area of Africa and various islands that belong to Oceania. It is defined because it is considered as the "rich" hemisphere and because its summer is the one that occurs between June and September while winter takes place between December and March.
Quite the opposite happens in the southern hemisphere as the seasons take place the other way around the northern ones. Another of the main hallmarks of this is that it is made up of Australia, important islands of Oceania, much of South America, various areas of Africa and some of the islands that belong to Asia.
With regard to the eastern and western hemispheres, we can clearly determine that while the latter would do America, the former would do the same with Europe, Asia, Africa and Oceania.
From the perspective of the geometry , the hemispheres are defined as each of the two halves of a sphere that is divided by a plane that passes through its center .
The concept of Cerebral hemisphere , meanwhile, refers to each of the structures that make up the largest portion of the brain . These two hemispheres have an inverse character and are asymmetrical (as is the case with both sides of the face of a person ).
The brain, experts say, has a deep sagittal fissure in the midline, which is known as interhemispheric or longitudinal cerebral fissure , which marks the division between the right hemisphere and the left hemisphere . This opening has a fold of the dura mater and houses the anterior cerebral arteries .
In the deepest part of this fissure is the hard body , which manages to unite both hemispheres by crossing the middle line and passing information from one side to the other.
The hemisphere located on the left side nucleates speech functions, the ability to to write , makes it possible to understand numbering and allows you to understand mathematics and logic, together with the skills required to convert a group of data into words, gestures and thoughts.
The hemisphere of the right side, meanwhile, is characterized by being the center of nonverbal viso-spatial character capabilities , more linked to feelings, sensations, prosody and special abilities.
Diverse are the diseases, conditions and pathologies that a person related to the brain can suffer and that will be the ones that considerably damage it and specifically one of the two hemispheres. Among them, it should be noted, for example, the aphasia that is that which occurs in the left cerebral hemisphere and that is characterized because who suffers it loses the ability to understand and produce language.
A cardiovascular accident, a craniocerebral trauma or tumors in the central nervous system are some of the causes that can lead to this type of disease.