The equator divides the Earth into two hemispheres.
Hemisphere is half of the Earth 's surface , segmented by a great circle (such as the equator or some meridian ). The term has its origin in the Latin word hemisphaerĭum , which in turn comes from a Greek root concept.
In relation to the equator line , it must be said that the planet can be divided into two parts: one known as the boreal hemisphere or northern hemisphere and another called the southern hemisphere or southern hemisphere . Along the Greenwich meridian , however, the terrestrial sphere adopts another division that is known as the eastern hemisphere and the western hemisphere .
It should be noted that, from the perspective of geometry , hemispheres are defined as each of the two halves of a sphere that is divided by a plane that passes through its center .
Hemispheres of the Earth
The northern hemisphere of planet Earth includes 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 characterized as a “rich” hemisphere and by its summer that occurs between June and September, while winter takes place between December and March.
Quite the opposite happens in the southern hemisphere since the seasons occur in reverse from those in the north. Another of its main hallmarks is that it is made up of Australia , important islands in Oceania , a large part 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 encompass America , the former would do the same with Europe , Asia , Africa and Oceania .
The interhemispheric fissure separates the hemispheres of the brain.
The term associated with the brain
The concept of cerebral hemisphere , for its part, 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 happens with both sides of a person's face).
The brain , experts say, has a very deep sagittal fissure in the midline, which is known as the 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 corpus callosum , which manages to unite both hemispheres by crossing the midline and passing information from one side to the other.
The cerebral hemispheres
The hemisphere located on the left side brings together the functions of speech, the ability to write , makes it possible to understand numeration and allows us to understand mathematics and logic, along with the skills required to convert a group of data into words, gestures and thoughts. .
The right hemisphere, for its part, is characterized as the center of non-verbal visual-spatial abilities , more linked to feelings, sensations, prosody and special skills.
There are various diseases, conditions and pathologies that a person can suffer related to the brain and that will considerably damage it and specifically one of the two hemispheres. Among them we should highlight, for example, aphasia, which is that which occurs in the left cerebral hemisphere and is characterized by the person suffering from it losing the ability to both understand and produce language.
A cardiovascular accident, head trauma or tumors in the central nervous system are some of the causes that can give rise to this type of disease.