A myelin daina kai hare hare na jijiya zaruruwa: aikin dawo da

A juyayi tsarin mutum da vertabrate da guda tsarin shirin da ya gabatar da cibiyar - kwakwalwa da kuma laka, da kuma na gefe sassa - tsawaita daga tsakiyar jikin na jijiyoyi, wanda wakiltar matakai na jijiya Kwayoyin - neurons.

Su sa siffofin na tsarin jijiya nama, da babban ayyuka na wanda excitability da watsin. Wadannan Properties an bayyana shi a sama da dukan tsarin fasali na neuronal membranes da su appendages, kunsha na wani abu kira myelin. A wannan labarin, za mu duba a cikin sifa da aiki na wannan fili, kazalika da gano hanyoyin mayar da shi.

Me neurocytes da kuma matakai rufe myelin

Yana da daidaituwa ba axons da dendrites da m Layer kunshi sia-gina jiki gidaje. Gaskiyar cewa ma'aikata ne a biophysical tsari, wanda dogara ne a kan maraunana lantarki hasken dake fitowa. Lokacin da wutar lantarki yanzu ke ta da waya, da karshen dole ne a rufe insulating abu don rage masha'a na lantarki hatsaisai kuma su hana karu a amperage. A wannan ayyuka a cikin jijiya fiber daukawa myelin daina kai hare hare. Bugu da ƙari kuma, shi ne goyon baya, da kuma samar da wani fiber abinci.

A sunadarai abun da ke ciki na myelin

Kamar mafi yawan cell membranes, shi ne wani lipoprotein yanayi. Bugu da ƙari, mai abun ciki ne sosai high - har zuwa 75%, da kuma gina jiki - 25%. Myelin a adadi kaɗan ma qunshi glycolipids da glycoproteins. Its sinadaran abun da ke ciki shi ne daban-daban a cikin kashin baya da kuma girman kwanyar jijiyoyi.

A farko akwai wani babban abun ciki na phospholipids - har zuwa 45%, da kuma sauran zo daga cholesterol kuma cerebrosides. Demyelination (Ina nufin myelin maye gurbin sauran abubuwa a jijiya matakai) take kaiwa zuwa wannan tsanani autoimmune cututtuka, kamar mahara sclerosis.

Daga mai guba ra'ayi, wannan tsari zai yi kama da wannan: da myelin daina kai hare hare na jijiya zaruruwa canza tsarinta, wanda aka farko bayyana a cikin wani karu a yawan sia ciki dangane da sunadarai. Bugu da ari ragewa adadin cholesterol, kuma Ya ƙãra ruwa abun ciki. Kuma duk wannan take kaiwa a hankali a hankali maye myelin dauke da oligodendrocytes ko Schwann Kwayoyin a kan macrophages, astrocytes da intercellular ruwa.

A sakamakon wadannan biochemical canje-canje zai zama mai kaifi karu a da ikon na axons su gudanar agitation har sai da cikakken tarewa na da nassi na jijiyar.

Features neuroglial Kwayoyin

Kamar yadda aka ambata riga, da myelin daina kai hare hare na axons da dendrites aka kafa tare da musamman Tsarin, halin da low mataki na permeability for sodium da kuma alli ions, sabili da haka da ciwon kawai Allaha iko (ba za su iya gudanar da jijiyar da kuma aiki da lantarki aiki).

Wadannan Tsarin ake kira glial Kwayoyin. Wadannan sun hada da:

• oligodendrocytes.
• fibrous astrocytes.
• ependymal Kwayoyin.
• jini astrocytes.

Dukan su suna kafa daga matsanancin Layer amfrayo - da ectoderm kuma da na kowa sunan - macroglia. Glia m, parasympathetic da somatic jijiyoyi wakilta Schwann sel (neyrolemmotsitami).

Tsari da kuma aiki na oligodendrocytes

Su wani bangare ne na tsakiya m tsarin da suke macroglia Kwayoyin. Tun myelin - mai gina jiki-sia tsarin, shi qara kudi na zumudi. A Kwayoyin kansu samar da wani electrically insulating Layer na jijiya endings a cikin kwakwalwa da kuma laka, da ake kafa riga a lokacin fetal ci gaba. Su tafiyar matakai obvorachivayut a cikin matsanancin folds na plasmalemma neurons da dendrites da axons. Sai dai itace cewa myelin - wani asali lantarki insulating abu, delimiting da jijiya matakai na gauraye jijiyoyi.

Schwann Kwayoyin da su siffofin

A myelin daina kai hare hare na gefe jijiyoyi tsarin kafa neyrolemmotsitami (Schwann Kwayoyin). Su rarrabe kunshi a kan gaskiyar cewa sun iya samar da daya kawai m daina kai hare hare na axon, kuma ba zai iya samar da harbe, kamar yadda shi ne muhimmi a oligodendrocytes.

Tsakanin Schwann Kwayoyin a yankin na 1-2 mm an sanya rabo bã tãre da myelin, da ake kira nodes na Ranvier. A cewar shi abruptly auku a aiwatar da lantarki hasken dake fitowa ta cikin axon.

Lemmotsity iya gyara jijiya zaruruwa, kazalika da yi trophic aiki. A sakamakon kwayoyin aberrations lemmotsitov Shell mitotic Kwayoyin fara uncontrolled division da girma, inda da ƙari ci gaba a sassa daban daban na cikin juyayi tsarin - schwannoma (neurinoma).

Rawar da microglia a cikin halakar da myelin tsarin

Microglia wakiltar macrophages iya phagocytosis da kuma iya gane daban-daban pathogenic barbashi - antigens. Godiya ga membrane rabe, da waɗannan glial Kwayoyin nuna enzymes - proteases da cytokines, kamar interleukin 1. Ya shine matsakanci na kumburi da kuma rigakafi.

A myelin daina kai hare hare, wanda aiki ne don ware da axial Silinda da kuma kyautata na jijiya turu iya lalace interleukin. A sakamakon haka, da jijiya "dage farawa danda" da kuma gudun da zumudi da aka rage muhimmanci.

Bugu da ƙari, cytokines, kunna rabe tsokane wuce kima alli ion kai a cikin jiki na neuron. Protease da phospholipase fara manne da wasu gabbansa da kuma matakai na jijiya Kwayoyin, wadda take kaiwa zuwa apoptosis - mutuwar wani ba tsari.

Ta fadi, watse a cikin barbashi, wanda ya cinye macrophages. Wannan sabon abu ne da ake kira excitotoxicity. Ana sa degeneration na neurons da su endings, abu don cututtuka irin Alzheimer ta da Parkinson ta cutar.

Myelinated jijiya zaruruwa na

Idan neuronal matakai - dendrites da axons, da myelin daina kai hare hare sutura, aka kira su myelinated da innervate kwarangwal tsoka, shigar da somatic rabo daga cikin na gefe m tsarin. Unmyelinated zaruruwa samar da autonomic juyayi tsarin da innervated gabobin.

Myelinated matakai da ya fi girma diamita fiye da wadanda ba fleshy, kuma an kafa kamar haka: axons barinta da jini membrane na glial Kwayoyin da form mikakke mezaksony. Sa'an nan, suna mika da Schwann Kwayoyin akai-akai kunsa a kusa da axon, forming concentric yadudduka. A cytoplasm da kuma tsakiya lemmotsita mayar da su cikin matsanancin Layer, wanda ake kira neurilemma ko Schwann daina kai hare hare.

A ciki Layer kunshi wani laminate lemmotsita mezoksona kira myelin daina kai hare hare. ta kauri a sashe daban-daban na jijiya ne ba iri daya ba.

Yadda za a mayar da myelin daina kai hare hare

Idan akai la'akari da rawar da microglia a jijiya demyelination, mun gano cewa, a karkashin mataki na macrophages da neurotransmitters (msl, interleukins), shi ne halakar myelin, wanda a bi take kaiwa zuwa tabarbarewar ikon watsa neurons da illa jijiyar tare da axon.

Wannan Pathology tsokani neurodegenerative effects: tabarbarewar fahimi matakai, musamman ƙwaƙwalwar ajiya da kuma tunani, da bayyanar da rashin daidaituwa na jiki ƙungiyoyi da lafiya motor basira.

A sakamakon haka, zai yiwu cikakken tawaya na haƙuri, wanda shi ne sakamakon wani autoimmune cuta. To, tambayar da yadda za a mayar da myelin, shi ne a halin yanzu musamman m. Irin wannan hanyoyin hada da farko a daidaita gina jiki-sia rage cin abinci, yau da kullum rayuwa, babu miyagun halaye. A tsanani lokuta, magani amfani da cututtuka, rage yawan balagagge glial Kwayoyin - oligodendrocytes.