Lapho sibhekisa ebuchosheni bomuntu, ngokuvamile sicabanga ukuthi yakhiwa ama-neurons anquma okwethu ukucabanga nokukhalipha. Lokhu kuyiqiniso kuphela kumaphesenti amancane.
Ingqondo yomuntu yakhiwe ngaphezu kwe- Ama-neurons ayizigidi ezingama-80.000, kepha leli nani limelela kuphela u-15% wamaseli esewonke wezitho zawo.
Amaseli nomsebenzi wawo ngaphakathi komzimba womuntu
Amanye ama-85% akhiwe ngamanye amangqamuzana amancanyana abizwa ngama-glial cell, abhekene nokwakha into ebizwa nge-glia efinyelela kuwo wonke amakhona ohlelo lwezinzwa.
Amaseli we-Glial aphethe ukusiza ama-neurons enqubweni yawo yokudlulisa imizwa ye-electrochemical ngohlelo lwezinzwa. Amaseli omzimba anesibopho sokuhlinzeka ngezakhi zomzimba, ukugcina ukwakheka noma ukusheshisa ukuqhutshwa kwe-neural uqobo, ukulungisa umonakalo nokunikeza amandla kuma-neurons.
Phakathi kwalawa maseli amaningi we-glial atholakala ebuchosheni, okuthiwa ama-oligodendrocyte ngokukwazi kwayo ukwakha imishanguzo yokuvikela i-myelin yama-axon wesistimu yezinzwa emaphakathi.
- UMyelin yi-lipoprotein evumela ukunwetshwa kwamandla okungenzeka wesenzo ngesikhathi nangebanga. Bavikela i-axon ekushayweni ugesi ngokwenza yayo path futhi ivimbela ukusabalalisa kwayo nge-membrane ye-neuronal.
- Ama-Oligodendrocyte, Amaseli weSchwann, ama-astrocyte, kanye ne-microglia yizigaba ezine ezibaluleke kakhulu zamaseli we-glial.
Amaseli kaSchwann
Babodwa abatholakala emithanjeni egijima umzimba wonke. (Isistimu yezinzwa ezibheke eceleni). Ziluhlobo lwamapulangwe amancane anjengeparele akhiwe myelin
Bayakwazi ukuhlukanisa i- "Isici sokukhula kwemizwa" (NCF), i-molecule evuselela ukukhula kwe-neuronal ngesikhathi sokukhula.
Amaseli weSchwann anesibopho sokwakhiwa kwe-myelin ohlelweni lwezinzwa lomngcele. Amaseli weSchwann ahlanganiswe azungeze i-axon eyodwa nge-cytoplasm yayo.
Ama-astrocyte
Angamaseli asondele kuma-neuron, abukeka kahle njenge-stellate, ngobukhulu obukhulu uma kuqhathaniswa nama-neurons, atholakala ohlelweni Isistimu yezinzwa emaphakathi (CNS) nange-optic nerve.
Ama-astrocyte Bayihlobo lamasosha angamalungu eBlood-brain Barrier (BBB), okuwulwelwesi oluvikelayo lwe-CNS umsebenzi walo ukuvimbela igazi ukuba lingagobhozi ngqo kulo.
Ama-astrocyte anesibopho sokuhlunga okungenzeka noma kungenzeki ku-CNS. Bavumela ukungena komoya-mpilo noshukela; ukondleka kwama-neurons.
Microglia
Yiqembu lamaseli elakha isisekelo sokuzivikela kobuchopho. Ngoba i-Blood-brain Barrier ayikuvumeli ukudlula kwamahhala kwamaseli amasosha omzimba, ubuchopho bunalo uhlelo lwayo lokuzivikela futhi lawa maseli amasosha avikelayo.
Umsebenzi oyisisekelo walawa maseli ukuvikela nokulungisa ubuchopho ekulimaleni okubangelwa amagciwane ahlaselayo, imfucumfucu yeseli nezifo.
Bahlala beskena i-CNS kwamapuleti alimele, ama-neuron nezinto ezithathelwanayo. Zizwela imvelo futhi ziyakwazi ukubona ushintsho oluncane ekwakhekeni kwezinto eziphilayo zezicubu zobuchopho. Amaseli ahlola i-CNS ukuthola nokunciphisa noma yiluphi uqwembe, izingcezu ze-deoxyribonucleic acid (DNA), izingxenyana ze-neuronal, amaseli afile, amaseli alimele nezinto zangaphandle. Bangabhekwa njengabesifazane besifazane bobuchopho ngokuhlanza imfucumfucu yeselula.
Ama-Oligodendrocyte
Luhlobo lweseli olubhekele ukwakha imishayo ye-myelin ezungeze ama-axon wesistimu yezinzwa emaphakathi. Zitholakala ebuchosheni kuphela futhi emnkantsheni wethambo (CNS). Zinezinqubo eziningi ezisonga ama-axon ezinzwa ezahlukahlukene.
Ama-myelin sheaths adalwe azungeze ama-axon ama-neuron enzelwe ukuwahlukanisa futhi andise ijubane lokudlulisa imizwa ye-electrochemical.
Le myelination yakhiwa ku-medulla umgogodla cishe isonto le-16 lempilo ye-intrauterine futhi uqhubeka ngemuva kokuzalwa kuze kube yilapho yonke imicu yezinzwa isuswa lapho ingane iqala ukuhamba. Ngisho nasebudaleni bomuntu, ama-oligodendrocyte aqhubeka nokuzala kusuka kumaseli ama-stem.
Izinhlobo zama-oligodendrocyte
Ama-Oligodendrocyte angahlukaniswa ikakhulukazi ngemisebenzi yawo, yize ihlelekile futhi ifana kakhulu. Kunezinhlobo ezimbili eziyinhloko: i-inter-fascicular ne-satellite.
- I-Los ama-oligodendrocyte aphakathi nendawo, zibhekene nokwakhiwa kwe-myelin sheaths, zakha ingxenye yendaba emhlophe yobuchopho.
- I-Los i-satellite oligodendrocyte, bakha ingxenye yento empunga, akubona abakhiqizi be-myelin, ababambeleli kuma-neurons, futhi abenzi umsebenzi wokuzihlukanisa. Imisebenzi yayo ayaziwa.
Imisebenzi
Njengoba kungaziwa kahle ukuthi iyini imisebenzi yama-satellite oligodendrocyte, sizongena kuphela encazelweni yemisebenzi ye-interfascicular ones.
Ukusheshisa kwe-Neural transmission
Isivinini samandla esenzo siyakhuphuka lapho ama-axon esetshenzisiwe. El ukusebenza kwesistimu okulungile i-hormonal and muscular iyathandwa ngaphambi kwesigqi esanele sokwenza i-neural. Ubunhloli babuye buthandwe isenzo salawa maseli kuma-neurons.
Ukuhlukaniswa kwe-membrane yeseli
Ukuhlukaniswa kwama-axon e-neuronal kusuka kwimvelo engaphandle yamaseli kuvimbela ukuvuza kwe-ion ngolwelwesi lweseli.
Ukuhlela uhlelo lwezinzwa
Njengoba ama-neurons engakwazi benza umsebenzi wabo bebodwa, amaseli we-glial, ikakhulukazi ama-oligodendrocyte e-interfascicular, anomthwalo wokuxhasa ukwakheka kwenethiwekhi kwama-neurons.
Ukusekelwa kokuthuthukiswa kwama-neurons
Ama-Oligodendrocyte angabakhiqizi bamaprotheni okuthi, ekusebenzisaneni kwawo nama-neuron, abenze bahlale bekhuthele, ngaleyo ndlela bavimbele ukufa kweseli okuhleliwe.
I-homeostasis eyengeziwe ye-fluid
Noma kunjalo ama-oligodendrocyte esethelayithi awunawo umsebenzi ocacile, Kubalulekile ukugcina ibhalansi ye-homeostatic yemvelo yangaphandle ye-neurons esondelene nabo.
Izifo ezihambisana ne-myelin
Isifo seMiller Fisher
Kuyinto ehlukile ye- I-Guillain-Barré syndrome, isifo esizimele esibonakala ngokukhiqizwa kwamasosha omzimba alwa ne-myelin kuma-neuron wesistimu yezinzwa zomzimba.
Ukuqhutshwa kwesiginali kulahlekile phakathi kwe- umzimba ne-CNS, okuholela ekukhubazekeni kwemisipha okungaba nzima. Ukusebenza kwezitho zomqondo nakho kulahlekile.
Izimpawu ezihambisana ne- lesi sifo i-ophthalmology, i-ataxia ne-areflexia. Uma uhanjelwa ngesikhathi, kulindeleke okuhle kokuthuthuka kwesikhathi eside
Charcot - Marie - Tooth disease, noma i-CMT
Yisifo esizalwa nefa esithinta izinzwa zomngcele, saziwa njenge-peripheral neuropathy. Kubanga ukulimala kwemizwa yomzimba, imbangela ejwayelekile yisifo sikashukela.
I-Multiple sclerosis
Isifo sesistimu yezinzwa esivimba noma sinciphise ukuxhumana phakathi kobuchopho nomzimba. Lokhu kwenzeka lapho i-myelin sheath evikela i- amangqamuzana ezinzwa alimele, athinta ubuchopho futhi ithambo umgogodla.
Izimpawu ezivame kakhulu zibangelwa ukulahlekelwa ibhalansi, ukunyakaza kwemisipha okungazibandakanyi, izinkinga zokuhamba, ubunzima bokuxhumanisa, ukuthuthumela, ubuthakathaka, ukuqunjelwa noma ukuphazamiseka kwamathumbu.
I-Amyotrophic lateral sclerosis (ALS)
Ihlasela ngokuqhubekayo ama-motor neurons, alawula imisipha engazibandakanyi. Zibonakala ngokuwohloka kancane kancane kuye ukufa kwe-neuronal kanye nomzimba.
Isifo sikaBaló noma i-Balc's concentric sclerosis
Ngokuvamile kuthinta izingane futhi kuyaqabukela abantu abadala. Kuqukethe ukulahleka kwe-myelin ebuchosheni. Kuyivelakancane futhi Kubangela ukukhubazeka okuqhubekayo, ukunyakaza okungazibandakanyi kwemisipha phakathi kwezinye izinkinga zemizwa.
I-Leuko-dystrophies
Kuqukethe ukuguqulwa kwe- umbono nohlelo lwemoto. Kubangelwa ukubhujiswa kwe-myelin ukukhubazeka kwe-enzymatic ekwakhekeni noma ekulondolozweni kwe-myelin noma ngezinqubo zemvelaphi yamathambo ezithathelwanayo, ezizimele, ezivuthayo noma ezinobuthi.