Precentral rotation: characteristics and functions of this part of the brain

If we look at a photograph of a human brain, the first thing we see is probably the outermost layer, a crumpled grayish mass. This most external and superficial part is the cerebral cortex, and the aforesaid folds its convolutions or turns and their grooves.

These folds emerge little by little during the brain development of the fetus, participating in the neuronal matter of which they are formed in various brain functions of great importance for our daily lives. One of them easily identifiable is the precentral turn, Which we will talk about throughout this article.

    The precentral gyrus: description and neuroanatomical location

    The precentral turn is one of the many cerebral turns or convolutions present in the cerebral cortex, being the part which at the observational level protrudes outward from these folds. this tour is part of the main engine areaIt is therefore relevant to its link with the ability to generate movement.

    This region of the brain it may be located in the frontal lobe, Just in front of Rolando’s cleft or central groove separating the frontal from the parietal. For this reason another of the names of the precentral turn is the one of turn or prerolandic turn.

    The precentral turn it is present in both hemispheres, Bordering Silvio’s slit at the bottom. Right after the slit we would find the post-central gyrus, while more rostral we would find the precentral slit or groove.

    Functionally, it would be deeply communicated with the secondary motor cortex and the supplementary motor cortex, which allow planning and programming of movement, and the Broca zone, which allows programming of movements related to the tongue. More too it has connections with other areas of the brain such as the cingulate or the hypothalamus.

    In the precentral bend and part of the central sulcus or Rolando, we can see represented the Penfield homunculus, being the two essential areas for the accomplishment of voluntary movement. Specifically, it is believed that the lower areas of the precentral gyrus control or innervate the head and facial regions, while the upper areas are believed to be responsible for innervation of the legs.

    Another remarkable aspect of this shift is that we can find there some of the largest pyramidal cells in the whole body, the Betz cells, reaching their axons all the way to the spinal cord.

    associated functions

    The precentral gyrus is a region of the brain with great importance with regard to activate normative functionality and human behavior, Be involved in various functions. Among them we highlight the following.

    1. Voluntary movement

    It is considered that in the precentral turn, identified with the primary motor cortex, there is the motor representation and the first connections responsible for allowing the movement of the different regions of the body. This region of the brain is largely due momentum and ability to move, Both simple and complex.

    2. Ability to move

    The ability to move or simply that of interacting physically with the environment it is, because of the need for the movement to be performed, one of the different functions in which there is participation of the precentral turn.

    3. Language and communication

    Our ability to communicate with others largely depends on the ability to move our voluntary muscles, so it largely depends on the action of the motor cortex including the precentral rotation of the face to be able to speak (which requires, among other things, movement). lips and tongue) or communicate by gestures (Muscles of the face and limbs).

    4. Response to stimulation

    Although the somatosensory system corresponds more to the post-central turn, the truth is that in experiments with monkeys it has been observed that in the precentral turn we can also find regions responsible for giving a motor response to the stimulation. , in particular in order to seek protection or defense against possible threats. This effect has been observed with unknown stimuli, with little or no response of the brain to stimuli to which it is already accustomed.

    Problems caused by his injury

    The presence of injuries in the precentral gyrus can generate, as one can imagine given the importance of their functions, serious repercussions on the lives of those who suffer them. An example of this is the presence of paralysis in the form of monopoly, hemiplegia, paraplegic quadriplegia, Being able to lose the ability to move different parts of the body.

    It has also been observed that it influences the praxis or performance of complex movements, causing the lesion of this bend to appear apraxia. Likewise, injury to the precentral gyrus has also been associated with the presence of Broca’s aphasia, making it impossible or complicating the production of the movements necessary for fluency.

    Bibliographical references:

    • Graziano, MSA; Alisharan, SR; Hu, X. and Gross, CG (2002). The effect of clothing: The tactile neurons of the precentral gyrus do not respond to the touch of the famous primate chair. PNAS, 99 (18): 11930-33.

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