SISTEMAI ASAB

SISTEMAI ASAB, asabiya, majmui tashkilaho (asabho, uqdaho, uzvhoi his, maynai organizmi hayvonot va odamro guyand, ki tasirotro dark, tahlil va ba uzvho naql karda, reaksiyahoi javobii mutobiqshavii organizmro ba amal meorad, hamai funksiyahoi organizmro dar tasiri mutaqobila bo muhit tanzim karda, faoliyati organizmro ba on muvofiq megardonad. Sistemai asab asosan az boftahoi hassosi asab tashkil yoftaast.

Soddatarinho Sistemai asab nadorand, vale baze patakchaho turchai dokhilihujayravie dorand, ki vazifai ba digar qismhoi hujayra guzaronidani hayajonro ijro mekunad. Sistemai asabi rudakovokon (gidra) az hama soddatar buda, Sistemai asabi muinashir (diffuzi) nomida meshavad. Dar chunin Sistemai asab hujayrahoi asabi ba vositai shokhahoi khud ba shabakae, ki hayajonro ba hamai samtho pahn menamoyad, payvast meshavad.

Dar rudakovokoni ozod hayotguzaronanda majmui hujayrahoi asabi dar chuqurihoi tana uqdaho (gangliyaho) hosil karda, bo shokhaho (torhoi asabi) payvast meshavand. Chunin namudi Sistemai asabro muntashiri-uqdavi menomand. In namudi Sistemai asab nisbatan hassosu ikhtisosi buda, hayajonro ba samthoi muayyan meguzaronad. Dar Sistemai asabi uqdavt hujayrahoi asabi dar uqdaho muttahid gashta bo hamdigar bo torhoi asab, reseptorho va uzvhoi korkun payvast shudaand. Dar bayni uqdahoi asabii in namudi Sistemai asab funksiya takhsis va murakkab meshavad. Yane sohibi akhbori muayyan, girehhoi muayyan shuda, uqdachahoi atrofro ba uqdahoi markazi tobe megardonand. Sistemai asabi hayvonoti muhrador az Sistemai asabi bemuhraho ba kulli farq mekunad va ba sistemai markazi va atrofi (periferi) judo meshavad. Sistemai markazii psab az harommagz va magzi sar iborat ast.

Sistemai asabi shirkhuron ba darajai olii taraqqiyoti khud rasidaast. Vohidi tarkibi va funksionalii Sistemai asab neyron meboshad, ki az tanai hujayrahoi asab va shokhahoi on (akson va dendritho) iborat ast. Neyronho vazifai qabul, tahlil va intiqoli hayajon va ba amal ovardani reaksiyaro ijro menamoyand.

Faoliyati Sistemai asab dar asosi du prosess — tahayyuj (pahnshavanda va pahnnashavanda meshavad) va tasakkun ba amal omada, dar shakli refleks zohir megardad. Sistemai asabi atrofi az asabhoi az mayna va maynai aqib ogozyobanda va torhoi asabi ba vositai harommagz az uqdahoyu shubahoi atrofii sistemai asabi vegetativi baroyanda iborat ast. Asabhoi dimogi (magzisari) az surokhihoi jumjuma berun mebaroyand. Mohiho, obkhokiho va khazandaho 10—11 juft, shirkhuronu odam 12 juft asabhoi dimogi dorand. Tarkiboti Sistemai asab tasirotro his karda, energiyai tasirotro ba energiyai tahayyuji asab tabdil medihad va on energiya dar shakli tahrikoti asabi az torhoi asab meguzarand. Dar Sistemai asab niz misli tamomi organizm mubodilai modda meguzarad. Dar natijai prosessi biokhimiyavi energiya hosil shuda, kori torhoi asab ba nizom medaroyad.

Dar faoliyati Sistemai asab (az yak neyron ba neyroni digar guzaronidani tahrikot) moddahoi faoli fiziologi — mediatorho roli muhim mebozand. Dar faoliyati Sistemai asab roli biotokho niz kalon ast. Onho alomati khosi prosessi tahayyuj buda, dar guzaronidani tahrikot ahamiyati kalon dorand. Sistemai asab faoliyati hayotii organizmro ba tartib medarorad. Az on hamai hissiyot, tafakkur va tasavvurot dar borai olami reali tashakkul meyobad. Shaklhoi gunoguni ehsosot, nutq, tafakkur va digar funksiyahoi oli bo Sistemai asab zich vobastaast. In faoliyatro mekhannzmhoi hassosi fiziologi — asabho ba amal meorand. Sokht, funksiya va inkishofi Sistemai asabi odamro nevrologiya meomuzad.

A. M. Pulodov.