The myelin m'chimake ulusi mitsempha: Ntchito kuchira

Mantha dongosolo la munthu ndi nyama zimene zili ndi umodzi structural dongosolo n'kupereka pakati - ubongo ndi msana, ndi mbali zotumphukira - anakafika ku matupi chapakati mitsempha akuimira njira ya maselo mitsempha - manyuroni.

akonzedwa Matupi awo ubongo minofu, ntchito yaikulu imene ndi excitability ndi madutsidwe. katundu izi anafotokoza kuposa mbali zonse structural wa nembanemba okhudza mitsempha ndi zokhudzana awo, wopangidwa mwa mankhwala otchedwa myelin. M'nkhaniyi tiona kapangidwe ndi ntchito ya pawiri izi, komanso kupeza njira zotheka kuti abwezeretse izo.

Chifukwa neurocytes ndi njira ataphimbidwa ndi myelin

Si axons mwangozi ndi dendrites ndi wosanjikiza zoteteza ongokhala maofesi zamadzimadzi-mapuloteni. Mfundo yakuti m'banja ndi ndondomeko biophysical, ozikidwa pa zilakolako ofooka magetsi. Pamene magetsi inawadutsa udzadutsa waya, yotsirizira ayenera yokutidwa ndi chimateteza zakuthupi kuchepetsa madyaidya ndikuledzera wa nyemba magetsi ndi kuteteza kuchepa amperage. Ntchito chomwecho mu mitsempha CHIKWANGWANI amanyamula myelin m'chimake. Komanso, thandizo, komanso amatipatsa chakudya CHIKWANGWANI.

Mipweya ya myelin

Ngati nembanemba kwambiri selo, ndi lipoprotein chikhalidwe. Komanso, mafuta okhutira ndi mkulu - mpaka 75%, ndi mapuloteni - 25%. Myelin zochepa komanso limapangidwa glycolipids ndi glycoproteins. mipweya ake ali osiyana mu misempha msana ndi cranial.

Poyamba pali zili mkulu wa phospholipids - mpaka 45%, ndipo ena amachokera mafuta ndi cerebrosides. Demyelination (i.e. myelin mmalo zinthu zina mu njira mitsempha) kumayambitsa matenda aakulu autoimmune, monga ofoola ziwalo.

Kuyambira mfundo mankhwala view, mnjira amaonekera izi: myelin m'chimake ulusi mitsempha kusintha kapangidwe, lomwe kwenikweni anawonetseredwa mu kuchepa kuchuluka zili zamadzimadzi poyerekezera ndi mapuloteni. Komanso kucheperachepera kuchuluka kwa mafuta ndi kuchulukitsa zili madzi. Ndipo zonse izi zimabweretsa m'malo mwapang'onopang'ono myelin munali oligodendrocytes kapena maselo Schwann pa macrophages, astrocytes ndi madzi intercellular.

The chifukwa cha kusintha amuzolengedwa adzakhala kuchepa lakuthwa mu luso la axons kuchita mukubwadamuka mpaka Letsani wathunthu wa ndimeyi wa zikhumbo mitsempha.

Features maselo neuroglial

Monga tanenera kale, myelin m'chimake a axons ndi dendrites aumbike ndi nyumba wapadera, yodziwika ndi digiri otsika permeability chifukwa ndi sodium ndi calcium ayoni, choncho ndi kokha kupumula Zoyenereza (sangathe kuchititsa zikhumbo mitsempha ndi ntchito ntchito magetsi).

nyumba zimenezi zimatchedwa maselo glial. Njirazi ndi monga:

• oligodendrocytes;
• fibrous astrocytes;
• ependymal maselo;
• plasma astrocytes.

Onse anapangidwa kuchokera wosanjikiza kunja kwa mwana wosabadwayo ndi - ndi ectoderm ndipo ali ndi dzina wamba - macroglia. Glia wachifundo parasympathetic ndi somatic misempha ankaimira Schwann maselo (neyrolemmotsitami).

Kapangidwe ndi ntchito ya oligodendrocytes

Ali mbali ya chapakati mantha dongosolo ndipo macroglia maselo. Popeza myelin - dongosolo mapuloteni-zamadzimadzi, izo kumawonjezera mlingo wa malemeredwe. Maselo okha kupanga wosanjikiza electrically chimateteza cha mathero mitsempha mu ubongo ndi msana, kupangidwa kale pa chitukuko yoopsa. njira zawo obvorachivayut mu makutu ake akunja a manyuroni plasmalemma ndi dendrites ndi axons. Iwo likukhalira kuti myelin - mfundo magetsi zokutira zitsulo zinthu, delimiting njira mitsempha ya mitsempha yosiyanasiyana.

maselo Schwann ndi zizindikiro zawo

The myelin m'chimake wa zotumphukira mitsempha dongosolo anapanga neyrolemmotsitami (Schwann maselo). Mbali awo ndi osiyana lili mu choona kuti akhoza kupanga chimodzi chokha m'chimake kuteteza axon, ndipo simungathe kupanga mphukira, monga chibadidwe oligodendrocytes.

Pakati pa maselo Schwann m'chigawo cha 1-2 mamilimita anayikidwa mbali wopanda myelin, otchedwa mfundo za Ranvier. Malinga ndi iye mwadzidzidzi amapezeka conduction kwa zikhumbo za magetsi mkati axon lapansi.

Lemmotsity angathe kukonza ulusi mitsempha, komanso kuchita ntchito trophic. Chifukwa cha aberrations majini lemmotsitov chipolopolo maselo mitotic kuyamba magawano kusalankhula ndi kukula, umene ndi chotupa anayamba mu madera osiyana a wamanjenje dongosolo - schwannoma (neurinoma).

Udindo wa microglia mu chiwonongeko cha dongosolo myelin

Microglia akuimira macrophages angathe phagocytosis ndipo anazindikira particles osiyana tizilombo - antigens. Ndiyamika maselo nembanemba, maselo amenewa glial kubala michere - proteases ndi cytokines, monga interleukin 1. Iye ali nkhoswe ya kutupa ndi chitetezo chokwanira.

The myelin m'chimake, amene ntchito ndi kupeza yamphamvu ofananira ndi kusintha kwa mopupuluma mitsempha akhoza kuonongeka interleukin. Chifukwa, mitsempha "anaonetsera poyera" ndi liwiro malemeredwe ali kwambiri yafupika.

Komanso, cytokines, mphamvu zolandilira imfayo kwambiri kashiamu ion zoyendera mu thupi la ubongo wa. Protease ndi phospholipase anayamba adzaphatikizana organelles ndi njira ya maselo mitsempha, imbaenda aputosisi - imfa ya kapangidwe anapatsidwa.

Iye n'kugwa, kuswa particles, imene umeze macrophages. zodabwitsazi amatchedwa excitotoxicity. Izo zimayambitsa alibe wa manyuroni ndi mapeto awo, zikubweretsa matenda monga Alzheimer ndi matenda Parkinson.

Myelinated mitsempha ulusi

Ngati njira okhudza mitsempha - dendrites ndi axons, ndi myelin m'chimake pogona, iwo amatchedwa myelinated ndi innervate chigoba minofu, kulowa gulu somatic wa mantha dongosolo zotumphukira. ulusi Unmyelinated kupanga dongosolo autonomic mantha ndi ziwalo innervated.

njira Myelinated ndi awiri lalikulu kuposa sanali minofu, ndipo anapanga motere: axons nacho madzi a m'magazi Kakhungu maselo glial ndi mawonekedwe liniya mezaksony. Ndiye, iwo amafikira ndi maselo Schwann mobwerezabwereza kukulunga padziko axon, chimene chinapanga zigawo concentric. The cytoplasm ndi phata lemmotsita anasamukira ku wosanjikiza akunja, wotchedwa neurilemma kapena Schwann m'chimake.

The M'kati imakhala laminate lemmotsita mezoksona otchedwa myelin m'chimake. wochindikala zigawo zosiyana za mitsempha sali yemweyo.

Kodi kubwezeretsa myelin m'chimake

Poganizira udindo wa microglia mu demyelination mitsempha, tinapeza pansi zochita za macrophages ndi timene (mwachitsanzo, interleukins), ndi kuwononga myelin, womwe kumabweretsa kuwonongeka kwa manyuroni mphamvu HIV ndi mkhutu zikhumbo mitsempha pamodzi axon lapansi.

kudwala Izi amakwiya zotsatira neurodegenerative: kuwonongeka kwa njira chidziwitso, makamaka kukumbukira ndi maganizo, maonekedwe a kusowa kwa mugwirizano kayendedwe thupi ndi luso zabwino za galimoto.

Chifukwa cha zimenezi, n'zotheka zonse chilema wodwalayo, yomwe ndi chotsatira chake cha matenda ndi autoimmune. Chotero funso mmene kubwezeretsa myelin, panopa makamaka pachimake. njira zimenezo zimaphatikizapo makamaka moyenera mapuloteni-zamadzimadzi zakudya, moyo zonse, pakalibe zizolowezi zoipa. Zikavuta, mankhwala ntchito matenda, kuchepetsa chiwerengero cha okhwima maselo glial - oligodendrocytes.