Somatosensory center

Thebasicunitofthesensoryareastructureisthecellcolumn,andthecellsinthesamecolumnhavethesamesensorytype.Theprojectedareaof​​thewholebodysurfaceiscalledthefirstcorticalsensoryarea,whichsensesthepain,temperatureandtouchofthebody,limbs,andsuperficialpartsoftheheadandface.Thesensationofthisareaischaracterizedbyclearpositioning,finedivisionoflabor,andaninverteddistributionofpositioninginthecortex.Therepresentativeareaof​​thelowerlimbsisonthetopofthecentralposteriorcortex,theupperlimbsareinthemiddle,andtheheadandfaceareonthelowerpart.Exceptthatthehead-faceconnectionisbilateral,theotherpartsarecontralateral.Thesizeoftherepresentativeareaof​​thecortexisadaptedtothedensityofinnervationandtheprecisionofsensation.Afterthecenter,thesecondsensoryareareturnstothelowerendtothebottomofthesylvianfissure,whichhasaroughanalysiseffect.Feelthedeepsensationofthemuscles,tendons,periosteumandjointsofthetrunkandlimbs.Theprojectionareaisinthemiddleandupperpartoftheposteriorgyrus,theparacentrallobulesandthecentralanteriorgyrusofthecerebralcortex,whichiscalledproprioception.Thesensorypathwaysofthebodyandheadandfacearegenerallyconductedbytertiaryneurons,andprojectedtothecorrespondingareasofthecerebralcortexthroughthethalamusandinternalcapsule.