Sensitive Homonculus

Description

There exists on the level of this territory, on the Gyrus post-exchange (ascending Circonvolution parietal) a topography which corresponds to the distorted shape of our body (one speaks about Somatotopie sensitive who is comparable with that of the homonculus of Wilder Penfield). A surface of Cortex corresponds to a surface of the body, but the representation of part of the body is all the more extended on the cortex which the sensitivity is fine, complex, rich in the body zone considered: for example the representation (picturesque) of the feet is larger than that of the legs. Thus, the general sensitivity of the body is projected on the level of the parietal lobe of the cerebral cortex, behind of the central furrow (fissure of Rolando). One distinguishes on his level three successive territories:

surface 3 corresponds to the primary reception, localized on the level of ascending parietal convolution (gyrus post-exchange).
and surfaces 1 and 2 correspond to the psychic surfaces.

Revision in prospect

Works of neurology in which figure the homunculus. June 14th, 2005, Dr. Christian Kell and his colleagues of Frankfort and Hamburg rectified an historical error at the time of the Congress of the Company of cartography of the human brain (Toronto). The error dated from the electric experiments of stimulations carried out in 1950 by Penfield and Rasmussen at the time of operations of neurosurgery (Kell and coll used a tactile stimulation and the functional IRM). Homunculus had been for one half-century with a projection of its genitals in the face médiale of the cerebral hemispheres, that is to say beyond the foot, and not in the place awaited, i.e. on the convexity of the posterior central gyrus.

See too

driving Homoncule

External bonds

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