Precentral gyrus: characteristics and functions of this part of the brain.

This fold of the brain is responsible for controlling several motor functions that we use every day.

If we look at a photograph of a human brain, probably the first thing we see is the outermost layer, a grayish wrinkled mass. This outermost and most superficial part is the cerebral cortex, and the aforementioned folds are its gyri or gyri and its sulci.

These folds gradually emerge during the brain development of the fetus, and the neuronal matter from which they are formed participates in different brain functions of great importance for our daily life. One of them, easily identifiable, is the precentral gyrus, which we are going to talk about later on.of which we are going to speak throughout this article.

The precentral gyrus: description and neuroanatomical location.

The precentral gyrus is one of the various cerebral gyri or convolutions present in the cerebral cortex, being the part that observationally protrudes outwards from these folds. This gyrus is part of the primary motor areaThis gyrus is part of the primary motor area, so that its link with the capacity to generate movement is relevant.

This brain region can be located in the frontal lobejust in front of Rolando's fissure or central sulcus that separates the frontal from the parietal. For this reason, another name for the precentral gyrus is the prerolandic gyrus or gyrus.

The precentral gyrus is present in both hemispheresThe precentral gyrus is present in both hemispheres, bordering the inferior part of the Sylvian fissure. Just after the fissure we would find the postcentral gyrus, while more rostrally we would find the precentral fissure or sulcus.

Functionally speaking, it would be deeply communicated with the secondary motor cortex and the supplementary motor cortex, which allow planning and programming movement, and Broca's area, which allows programming movements linked to language. In addition, it also It also has connections with other brain areas such as the cingulum or the hypothalamus..

In the precentral gyrus and part of the central sulcus or Rolando's sulcus we can see Penfield's homunculus represented, being both areas essential for the realization of voluntary movement. Specifically, it is considered that the inferior areas of the precentral gyrus control or innervate the regions of the head and face, while the superior parts would be in charge of innervating the legs.

Another noteworthy aspect of this gyrus is that it contains some of the largest pyramidal cells in the body, the Betz cells, whose axons reach the spinal cord.

Associated functions

The precentral gyrus is a brain region of great importance in enabling normative functionality and human behavior. normative functionality and human behavior, being involved inbeing involved in several functions. Among them we highlight the following.

Voluntary movement

It is considered that in the precentral gyrus, identified with the primary motor cortex, there is the motor representation and the first connections responsible for allowing the movement of different body regions. This brain region is largely responsible for the impulse and the capacity of movement, both simple and complex.both simple and complex.

2. Movement capacity

The ability to move or simply the ability to interact with the environment physically is, due to the need of movement to be performed, one of the different functions in which the precentral gyrus is involved.

3. Language and communication

Our ability to communicate with others depends to a large extent on the ability to move our voluntary musculature, thus depending to a large extent on the action of the motor cortex of which the precentral gyrus is part in order to be able to speak (something that requires among other things the movement of the lips and tongue). or communicate by means of gestures (musculature of the face and limbs).

4. Response to stimulation

Although the somatosensory system corresponds rather to the postcentral gyrus, it is true that during experiments with monkeys it has been observed that in the precentral gyrus we can also find regions in charge of giving motor response to stimulation, concretely to seek protection or defense against possible threats.. This effect has been observed with unfamiliar stimuli, the brain response being lower or non-existent to stimuli to which it is already accustomed.

Problems generated by its lesion

The presence of lesions in the precentral gyrus can generate, as can be imagined based on the importance of its functions, serious repercussions in the life of the sufferer. One example of this is the presence of paralysis in the form of monoplegia, hemiplegia, paraplegia, or tetraplegiaThe ability to move different parts of the body may be lost.

It has also been observed that it has influence in the praxias or realization of complex movements, provoking the lesion of this gyrus the appearance of apraxias. Likewise, the lesion of the precentral gyrus has also been associated with the presence of Broca's aphasia, making impossible or complicating the production of the movements necessary to express oneself fluently.