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December 03, 2016 00:02

The frontal lobe of the brain

frontal lobe (lobus frontalis) is located in the anterior part of each of the cerebral hemispheres.It ends in front frontal pole and bounded below by the lateral sulcus (sulcus lateralis; Sylvian fissure), deep and behind the central sulcus.The central sulcus (sulcus centralis; rolandova furrow) is located in the frontal plane.It starts at the top of the medial surface of the cerebral hemisphere, dissecting across its top edge down, without interruption, in the upper-lateral surfac

e of the hemisphere down and ends just short of the lateral sulcus.

front of the central sulcus, almost parallel to it, is predtsentralnaya furrow (sulcus precentralis).It ends at the bottom, before reaching the lateral sulcus.Predtsentralnaya furrow is often interrupted in the middle part, and consists of two separate grooves.From predtsentralnoy furrows forward directed upper and lower frontal furrows (sulci frontales superior et inferior).They are located almost parallel to each other and divide the upper-lateral surface of the frontal lobe in the gyrus.Between the central sulcus behind and predtsentralnoy front furrow is ascending frontal convolution (gyrus precentralis).Above the top of the frontal furrow is the upper frontal gyrus (gyrus frontalis superior), which occupies the upper part of the frontal lobe.Between the upper and lower frontal furrow stretches average frontal gyrus (gyrus frontalis medius).

downward from the bottom of the frontal furrow is inferior frontal gyrus (gyrus frontalis inferior).At this meander branches protrude from the bottom of the lateral sulcus: the ascending branch (ramus ascendens) and anterior branch (ramus anterior), which divide the lower part of the frontal lobe, hover over the front part of the lateral grooves, into three parts: tegmental, triangular and orbital.Tegmental portion (frontal tire, pars opercularis, s. Operculum frontale) is located between the ascending branch and department predtsentralnoy bottom of the furrow.This part of the frontal lobe is so called because it covers lies in the depth of the furrow ostrovkovuyudolyu (island).The triangular part (pars triangularis) is located between the ascending branch of the back and front, front.The orbital part (pars orbitalis) lays down branches from the front, proceeding to the bottom surface of the frontal lobe.At this point, the lateral groove extends, in connection with which it is called the lateral fossa of the brain (fossa lateralis cerebri).

function of the frontal lobes is associated with the organization of voluntary movement, the motor mechanism of speech and writing, the regulation of complex forms be led, thinking processes.

By afferent systems of the frontal lobe are deep sensitivity conductors (they end in pretsetralnoy gyrus) and numerous associative links from all other lobes of the brain.The upper layers of the cortex cells of the frontal lobes involved in the work of the kinesthetic analyzer: they are involved in the formation and regulation of complex motor acts.

The frontal lobes begin various efferent motor system.In the V layer of the precentral gyrus are gigantopiramidalnye neurons that make up the spinal and cortical-cortical-nuclear path (pyramidal system).From extensive extrapyramidal parts of the frontal lobes in the premotor area of ​​her cortex (mostly from cytoarchitectonic fields 6 and 8) and its medial surface (field 7, 19) are multiple conductors to subcortical and stem formations (fronto-thalamic, fronto-palpidarnye, frontonigralnye,fronto-rubralnye et al.).The frontal lobes, in particular in their poles, starting fronto-cerebellopontine path included in the voluntary movement coordination system.

These anatomno-fizologicheskie features explain why patients with lesions of the frontal lobes are violated mainly motor functions.In the sphere of the higher nervous activity also violated motility speech act and behavioral acts relating to the implementation of complex motor functions.

whole cortical surface of the frontal lobe is anatomically divided into three components: the dorso-lateral (convexital), medial (forming the interhemispheric gap) and orbital (basal).

In front of the central gyrus contains the motor projection area to the opposite side of the body muscles (in the reverse order of its location on the body).In the posterior part of the second frontal gyrus is the 'center' eyes and turning heads in the opposite direction, and in the posterior part of the inferior frontal gyrus Broca localized area.

electrophysiological studies showed that neurons in the premotor cortex may respond to visual, auditory, somatic, olfactory and taste stimuli.Premotor region is able to modify the motor activity due to their connections with the caudate nucleus.It also provides a process sensorimotor relationships and focused attention.The frontal lobes of modern neuropsychology in characterized as a block of programming, regulation and control of complex forms of activity.