From the Latin word scissūra, the idea of fissure lets refer to a opening or cleft that is registered in some structure. It may be a groove that occurs naturally or is caused by some type of injury or disease.
It is common for the concept of fissure to be used to name the folds found in the brain, the cerebellum and the medulla oblongata. The intercerebral fissure, also called interhemispheric fissure, performs the division of the brain in two hemispheres that are linked to each other through the hard body.
These hemispheres, in turn, are divided into lobes by other fissures. The Rolando fissureIn this framework, it allows to distinguish between the frontal lobe and the parietal lobe. The Silvio fissure, for its part, separates the temporal lobe from the parietal lobe and the frontal lobe. The calcarine fissure, the Broca’s fissure, the superfrontal fissure and the simian fissure are other fissures present in the brain.
In the cerebellum are the longitudinal fissure, the horizontal fissure, the posterolateral fissure and the adoccipital fissure, While in the medulla oblongata you can recognize the posterior medial fissure.
There are also fissures in other parts of the body beyond the head. Among them we can name the glottis fissure (in the throat), the corneal fissure (in the eye), the anti-tragohelicin fissure (in the ear) and many others.
Certain fissures are pathological and appear before the emergence of certain disorders. That is the case of Harrison’s groove, which is seen with advanced rickets, and Liebermeister groove, produced by compression in the rib area, for example.
About Silvio’s fissure
As evidenced a few paragraphs above, along with Rolando’s fissure, Silvio’s is one of the most important in the brain of our species, and in fact it is also among the easiest to see. It is located in the lower part of the two hemispheres, in the line known by the name of naso-lambdoid, and then crosses almost the entire surface of the brain.
One of the reasons that make this fissure one of the most relevant in our anatomy it is the fact that it separates the parietal and temporal lobes, as well as the temporal and frontal lobes in its lower part. Furthermore, there is no deeper cleft in the human brain; so much so, that it houses at the bottom of its walls the insula, the so-called fifth lobe of the brain, and the transverse temporal gyrus, who is involved in the audition process.
Some diseases have the characteristic that the Silvio fissure does not form properly or that it is altered in some way. At Alzheimer’s disease, for example, throughout your developing it causes the cleft to widen, as a result of the degeneration that neuronal tissue undergoes. This is not exclusive to this disease, but can also be seen in other neurodegenerative types and in some dementias.
On the other hand is the lissencephaly, a anomaly that occurs during neuronal development and is characterized by the smooth appearance of the brain, since it causes it to have few or no furrows, due to an extreme percentage of neuronal migration: either its absence, a deficit or an excess of the same.
The perisilvian syndrome leads to certain motor problems or cases of paralysis on the face, and this is because developmental disorders occur in the parts of the brain that surround Silvio’s fissure.