Xa sibhekisa kwingqondo yomntu, sicinga ngokubanzi ukuba yenziwe zii-neurons ezimisela zethu ukucinga kunye nobukrelekrele. Ewe oku kuyinyani kuphela kwipesenti encinci.
Ingqondo yomntu yenziwe ngaphezu kwe I-80.000 yezigidi ze-neurons, kodwa eli nani limele kuphela iipesenti ezili-15 zeeseli zizonke zamalungu awenzayo.
Iiseli kunye nomsebenzi wazo emzimbeni womntu
Enye i-85% yenziwe ngamanye amaseli amancinci abizwa ngokuba yi-glial cell, anoxanduva lokwenza into ebizwa ngokuba yi-glia efikelela kuzo zonke iimbombo zenkqubo ye-nervous.
Iiseli ze-Glial zinoxanduva lokunceda ii-neurons kwinkqubo yazo yokudlulisa iimpembelelo ze-electrochemical ngokusebenzisa inkqubo ye-nervous. Iiseli ze-Glial zinoxanduva lokubonelela ngezondlo, ukugcina ulwakhiwo okanye ukukhawulezisa ukuhanjiswa kwe-neural uqobo, ukulungisa umonakalo kunye nokubonelela ngamandla kwi-neurons.
Phakathi kwezi iiseli ezininzi ze-glial ezifumaneka kwingqondo, oko kubizwa ngokuba ii-oligodendrocyte ngokukwazi kwayo ukwenza i-myelin sheaths zokukhusela ii-axon zenkqubo ye-nervous system.
- UMyelin yi-lipoprotein evumela ukwanda kwesenzo esinokubakho ngexesha kunye nomgama. Bayayikhusela i-axon kwimpembelelo yombane ngokwenza yayo indlela kunye nokuthintela ukusasazeka kwayo ngenwebu ye-neuronal.
- IiOligodendrocyte, Iiseli zeSchwann, ii-astrocyte, kunye ne-microglia zezona klasi zibalulekileyo zeeseli ze-glial.
Iiseli zeSchwann
Zizo kuphela ezifumaneka kwiimbilini ezihamba emzimbeni wonke. (Inkqubo yemithambo-luvo). Luhlobo lweepasile ezinjengeeperile ezinjenge-microscopic ezenziwe myelin
Bayakwazi ukwahlula "Ukukhula kwemithambo" (NCF)Imolekyuli evuselela ukukhula kwe-neuronal ngexesha lokukhula.
Iiseli zeSchwann zinoxanduva lokwenziwa kwe-myelin kwinkqubo yoluvo yangaphakathi. Iiseli zeSchwann zihlanganiswe zijikeleze i-axon enye ngecytoplasm yayo.
Astrocyte
Ziiseli ezikufutshane nee-neurons, zi-stellate ngembonakalo, zikhulu ngobukhulu ngokuthelekiswa nee-neurons, ziyafumaneka kwinkqubo Inkqubo ye-nervous central (CNS) kunye ne-optic nerve.
Astrocyte Luhlobo lwamajoni angamalungu e-Blood-brain Barrier (BBB), eyimbumba ekhuselayo ye-CNS enomsebenzi wayo kukungavumeli igazi ukuba lingene ngqo kulo.
Ii-Astrocyte zinoxanduva lokuhluza into enokwenzeka okanye engenzeki kwi-CNS. Bavumela ukungena kweoksijini kunye neglucose; ukondla kwee-neurons.
I-Microglia
Liqela leeseli ezenza isiseko somzimba sokusebenza komzimba. Kuba isithintelo segazi-lobuchopho alikuvumeli ukuhamba ngokukhululekileyo kweeseli zamasosha omzimba, ingqondo inenkqubo yayo yokuzikhusela kwaye ezi seli ngamajoni azikhuselayo.
Umsebenzi osisiseko wezi seli kukukhusela kunye nokulungisa ingqondo ekonzakaleni okubangelwe ziintsholongwane, inkunkuma yeseli kunye nezifo.
Bahlala beskena i-CNS iipleyiti ezonakeleyo, ii-neurons kunye neearhente ezosulelayo. Zinovelwano kwindalo esingqongileyo kwaye ziyakwazi ukubona olona tshintsho lincinci kubume bendalo kwizihlunu zobuchopho. Iiseli ziskena i-CNS ukukhangela kunye nokuthomalalisa nasiphi na isicwecwe, i-deoxyribonucleic acid (i-DNA), iziqwengana ze-neuronal, iiseli ezifileyo, iiseli ezonakeleyo kunye nezinto zangaphandle. Banokuthathwa njengabafazi bengqondo ngokucoca i-debris yeselula.
IiOligodendrocyte
Luhlobo lweseli elinoxanduva lokwenza i-myelin sheaths ejikeleze ii-axon zenkqubo ye-nervous system. Zibekwe kuphela kwingqondo kwaye kumongo wethambo (CNS). Zineenkqubo ezininzi ezisonga ii-axon zeeuron ezahlukeneyo.
I-myelin sheaths eyenziweyo ejikeleze ii-axon ze-neurons yenzelwe ukubahlukanisa kwaye yonyuse isantya sokuhanjiswa kweempembelelo ze-electrochemical.
Olu lwazi lwenziwa kwi-medulla umnqonqo malunga neveki ye-16 yobomi be-intrauterine kunye nenkqubela phambili emva kokuzalwa kude kube phantse yonke imicu yentsimbi i-myelinated ngexesha umntwana aqala ukuhamba. Nokuba sele umdala umntu, ii-oligodendrocyte ziyaqhubeka nokuzala kwakhona kwiiseli ezinesiqu.
Iindidi zeoligodendrocyte
Ii-Oligodendrocyte zinokwahlulwa ikakhulu yimisebenzi yazo, nangona zenziwe ngendlela efanayo kunye neemolekyuli ezifanayo. Zimbini iintlobo eziphambili: i-inter-fascicular kunye ne-satellite.
- Los i-oligodendrocyte ze-interfascicular, linoxanduva lokwenziwa kwe-myelin sheaths, eyinxalenye yemicimbi emhlophe yengqondo.
- Los i-satellite oligodendrocyte, ziyinxalenye yento engwevu, azivelisi i-myelin, azihambelani ne-neurons, kwaye azenzi msebenzi wedwa. Imisebenzi yayo ayaziwa.
Imisebenzi
Kuba ayaziwa ncam ukuba yintoni imisebenzi ye-satellite oligodendrocyte, siza kuya kwinkcazo yemisebenzi ye-interfascicular ones.
Unikezelo lonikezelo lonikezelo
Isantya sezinto ezinokwenzeka xa kuthe zonyuka xa ii-axon ziye zagqitywa. El inkqubo echanekileyo yokusebenza i-hormonal and muscular iyathandwa ngaphambi kwesingqisho esaneleyo sokuqhutywa kwe-neural. Ubukrelekrele bukwathandwa sisenzo seeseli kwii-neurons.
Iseli yokwahlulahlula yodwa
Ukubekwa ecaleni kwee-axon ze-neuronal ezivela kwindawo engaphandle yeeseli kuthintela ukuvuza kwe-ion nge-membrane yeseli.
Ukucwangciswa kwenkqubo yemithambo-luvo
Kuba ii-neurons azinakho benza umsebenzi wabo bodwa, iiseli ze-glial, ngakumbi ii-oligodendrocyte ze-interfascicular, zinoxanduva lokuxhasa ubume benethiwekhi yee-neurons.
Inkxaso yophuhliso lweeuron
Ii-Oligodendrocyte ngabavelisi beeprotheyini abathi, ekusebenzisaneni kwabo nee-neurons, zibenze bahlale bekhuthele, oko ke kuthintela ukusweleka kweeseli okucwangcisiweyo.
I-extracellular fluid homeostasis
Nangona kunjalo i-oligodendrocyte yesathelayithi ayinanto icacileyo, zibalulekile ukugcina ulungelelwaniso lwasekhaya lwendawo engaphandle ye-neurons ekufuphi kubo.
Izifo ezinxulumene ne-myelin
Isifo seMiller Fisher
Yinto eyahlukileyo I-Guillain-Barré syndrome, isifo esizenzekelayo esibonakaliswa yimveliso ye-antibodies ngokuchasene ne-myelin kwii-neuron zenkqubo ye-neripheral ye-nervous system.
Ukuqhutywa kwesiginali kulahlekile phakathi kwe umzimba kunye ne-CNS, ekhokelela ekukhubazekeni kwezihlunu okunokuba nzima. Ukusebenza kwamalungu emvakalelo nako kulahlekile.
Iimpawu ezinxulunyaniswa ne esi sifo zamehlo, i-ataxia kunye ne-areflexia. Ukuba izinyaswe ngexesha, inezinto ezilindelekileyo ezilungileyo zokuphuculwa kwexesha elide
Isifo seCharcot-Marie-Tooth, okanye i-CMT
Sisifo esivela kwilifa esichaphazela imithambo-luvo, siyaziwa njenge-peripheral neuropathy. Ibangela ukonakala kwemithambo-luvo, oyena nobangela uqhelekileyo sisifo seswekile.
Isifo sokugubhuka
Isifo sentsholongwane esivimba okanye sicothise unxibelelwano phakathi kwengqondo nomzimba. Oku kwenzeka xa i-myelin sheath ekhusela i iiseli zemithambo-luvo zenzakele, zichaphazela ingqondo kunye Umongo umqolo.
Iimpawu ezixhaphakileyo zibangelwa kukuphulukana nomlinganiso, ukungahambelani kwezihlunu, iingxaki zokuhamba, ubunzima bokulungelelanisa, ukungcangcazela, ubuthathaka, ukuqhina okanye ukuphazamiseka kwamathumbu.
I-Amyotrophic lateral sclerosis (ALS)
Ihlasela ngokuthe ngcembe iimotor neurons, ezilawula izihlunu ezingafunekiyo. Babonakaliswe ukonakala ngokuthe chu ukuya kwi- ukufa kwe-neuronal kunye nomzimba.
Isifo sikaBaló okanye isifo sikaBaló sokugxininisa kwistlerosis
Ichaphazela ngokubanzi abantwana kwaye kunqabile ukuba ngabantu abadala. Inokulahleka kwe-myelin kwingqondo. Inqabile kwaye yayo Kubangela ukukhubazeka okuqhubela phambili, ukungahambelani kokuzibandakanya kwezihlunu phakathi kwezinye iingxaki zemithambo-luvo.
I-Leuko-idystrophi
Inezinto eziguqulweyo ze umbono kunye nenkqubo yeemoto. Kubangelwa kukutshatyalaliswa kwe-myelin ngeziphene ze-enzymatic ekubunjweni okanye kulondolozo lwe-myelin okanye iinkqubo ezosulelayo, ezenzekelayo, ezinokudumba okanye imvelaphi yemithambo enetyhefu.