The myelin selateng sa likhoele methapo ea kutlo: mosebetsi hlaphoheloa

The tsamaiso ea methapo ea monna le vertebrates na ea se nang molekane mehaho mwango mpe hlahisa setsi - boko le lesapong la mokokotlo, 'me likarolo tse pheriferale - extending tsoa mele bohareng ea methapo ea kutlo, e leng emela dithulaganyo ea lisele methapo ea kutlo - methapo ea kutlo.

sete liforomo bona neural dinama tse nyenyane tse, mesebetsi e ka sehloohong ea e excitability le conductivity. thepa tsena di o ile a hlalosa hore ka holim'a litšobotsi tsohle mehaho ea lera la neuronal le appendages bona, e bopilweng ka ntho e bitswang myelin. A sehloohong sena a re tla sheba sebopeho le mosebetsi wa komponeng ena, hammoho le ho fumana litsela tsa ho bonolo ho tsosolosa eona.

Hobaneng neurocytes le dithulaganyo koahetsoe ke myelin

Ho na axons iketsahalletseng le dendrites na le lera le sireletsang e entsoeng ka mehahong lipid-protheine. 'Nete ea hore setheo e ke tshebetso biophysical, e leng e thehiloe litakatso fokolang motlakase. Ha motlakase hona joale o tsoela ka terata e, e qetellang e lokela ho koahetsoeng ka li sireletsang serameng lintho tse bonahalang ho fokotsa dissipation tsa linaoa tsa motlakase le ho thibela fokotseha ka amperage. Mesebetsi e tšoanang ka ho methapo ea kutlo faeba jarelang myelin selateng. Ho feta moo, ho ke ke tšehetso, 'me hape e fana ka lijo le litlheferetsi.

The lik'hemik'hale la myelin

Joaloka lera la ho fetisisa seleng, ke lipoprotein tlhaho. Ho feta moo, mafura dikahare ke phahameng haholo - ho fihlela ho 75%, mme protheine - 25%. Myelin tse nyenyane le tsona kenyelletsa ditokiseletso glycolipids le glycoproteins. lik'hemik'hale lona e fapaneng ka methapo lesapo la mokokotlo le cranial.

Qalong ho na le dikahare tse phahameng tsa phospholipids - ho fihlela ho 45%, 'me ba bang e tsoa ho k'holeseterole le cerebrosides. Demyelination (i.e. myelin nka sebaka sa lintho tse ling ka dithulaganyo methapo ea kutlo) isang mafu a joalo haholo autoimmune, tse kang multiple sclerosis.

Tswa ntlha lik'hemik'hale maikutlo, tshebetso ena e ne e tla shebahala joang hona: ho myelin selateng sa likhoele methapo ea kutlo ho fetola sebopeho sa eona, e leng e ka sehloohong o ile a bontša ka ea fokotseha ka peresente ya dikahare lipid mabapi le liprotheine. Ho ekelletsa moo fokotseha le palo ya k'holeseterole 'me e ile ea eketseha dikahare metsi. Le tsohle ona o isa ho Phetolo butle-butle myelin nang oligodendrocytes kapa liseleng tsa Schwann ka macrophages, astrocytes le mokelikeli intercellular.

Le ka lebaka la liphetoho tsena skeletal tla ea fokotseha hlabang ka bokhoni ba axons ho khanna pherekano fihlela emisang feletseng tsa temana ea litakatso tsa methapo ea kutlo.

Features lisele tse neuroglial

Joalokaha ho se ho boletsoe, ho myelin selateng sa axons le dendrites Ho thehoa le mehaho e khethehileng, tšoauoa ka tsela e itseng e tlase ya e lumellang metsi ho kena tsa sodium le k'halsiamo ions, 'me ka hona ba le feela phomotse tse khonehang (ba ke ke ba tsamaisa litakatso tsa methapo ea kutlo le ho sebetsa mosebetsi motlakase).

dibopeho tsena li bitsoa lisele tse glial. Tsena li akarelletsa:

• oligodendrocytes;
• fibrous astrocytes;
• ependymal lisele tse;
• lero la mali astrocytes.

Kaofela ha bona ba thehoa ho tloha lera le ka ntle la embryo le - ho ectoderm le na le lebitso le tloaelehileng le sebelisoang malapeng - macroglia. Glia le kutloelo-bohloko, parasympathetic le somatic methapo emeloang Schwann lisele tse (neyrolemmotsitami).

Sebopeho le mosebetsi wa oligodendrocytes

Ba karolo ea tsamaiso ea methapo e bohareng le e ke macroglia liseleng. Kaha myelin - ka sebopeho nang le protheine e lipid, ho eketsa lebelo la nyakallo. Lisele tse ho bona ka bobona theha e lera pellet li sireletsang serameng sa dipheletso methapo ea kutlo e bokong 'me lesapong la mokokotlo, ho thehoa se nakong ntshetsopeleng fetal. dithulaganyo bona obvorachivayut ka lemenong lona le ka ntle la methapo ea kutlo plasmalemma le dendrites le axons. E fellang kateng le hore myelin - ea motheo ea motlakase li sireletsang serameng tse bonahalang, delimiting dithulaganyo le methapo ea kutlo ea methapo ea kutlo e tsoakiloeng.

lisele tse Schwann le litšobotsi tsa bona

The myelin selateng sa pheriferale methapo oona tsamaisong thehoa neyrolemmotsitami (Schwann lisele tse). Tšobotsi bona ikhethang e na ha e le hantle e le hore ba ka theha 'ngoe feela selateng sa sireletsa axon,' me ke ke theha letlobo, e le ke ka tlhaho ho oligodendrocytes.

Pakeng tsa lisele tse Schwann a le sebakeng sa 1-2 limilimithara behoa likarolo bosula le bo sa myelin, seo ho thoeng ke nodes ya Ranvier. Ho ea ka mo ho panya ha leihlo le hlaha conduction la litakatso tsa motlakase ka hare axon ena.

Lemmotsity khona ho lokisa likhoele methapo ea kutlo, hammoho le ho phetha mosebetsi trophic. Ka lebaka la aberrations liphatsa tsa lefutso lemmotsitov shell lisele tse mitotic qala ho karohano sa laoleheng 'me ka kholo ea, oo ka oona hlahala ntshetswa pele likarolong tse fapaneng tsa tsamaiso ea methapo - schwannoma (neurinoma).

Karolo e phethoang ke microglia ka ho timetsoa ha sebopeho myelin

Microglia emela macrophages khona ho phagocytosis le khona ho lemoha likaroloana fapaneng pathogenic - antigens. Thanks ho receptors le lera, lisele tsena glial hlahisa enzyme - proteases le ea tse ling, tse kang interleukin 1. O ke mokena-lipakeng oa ho ruruha le sireletsehile maloetseng ana.

The myelin selateng sa, eo mosebetsi ke ho itšehla ea silindara axial le ntlafatso tšusumetso e tsoang ho methapo ea kutlo e ka senyeha interleukin. Ka lebaka leo, le methapo ea kutlo "a beha nang letho" le lebelo la nyakallo e haholo tsa fokotswa.

Ho feta moo, ea tse ling, activating receptors qholotsa tsela e feteletseng k'halsiamo Ion tsamaisa ka 'mele oa neuron ena. Protease le phospholipase qala ho khomarela organelles le dithulaganyo ea lisele methapo ea kutlo, eo e isa apoptosis - lefu la sebopeho sa fanoeng.

O ile a liha, ho roba ka likaroloana, eo harola macrophages. ketsahalo ena e bitsoa excitotoxicity. Ao bo a bakang degeneration tsa methapo ea kutlo le dipheletso bona, ea isang ho mafu a kang la Alzheimer le lefu Parkinson.

Myelinated methapo ea kutlo likhoele tsa

Ha dithulaganyo neuronal - dendrites le axons, ho myelin selateng sa tšireletso, ba ba bitsoa myelinated le innervate ya marapo mesifa, kena karohano somatic tsa tsamaiso ea methapo pheriferale. likhoele Unmyelinated theha tsamaiso autonomic methapo le makala innervated.

dithulaganyo Myelinated na le bophara ba tse khōloanyane ho feta bao e seng linama, 'me ba thehoa ka tsela e latelang: axons hlokomoloha le lero la mali lera ea lisele glial le foromo guttate mezaksony. Ka mor'a moo, ba ile ba ba atoloswa le lisele tse Schwann ho pheta-pheta thatela ho pota axon e, eaba ba etsa le dikarolo concentric. The cytoplasm le khubung lemmotsita a susumelletseha hore a lera ka ntle, e leng o bitsoa neurilemma kapa Schwann selateng.

Lera le ka hare le bopilwe ka laminate lemmotsita mezoksona bitsoa myelin selateng. Botenya ba lona e ka likarolo tse fapaneng tsa methapo ea kutlo le ha ho tšoane.

Tsela ea ho tsosolosa myelin selateng

Ho nahana ka karolo e phethoang ke microglia ka demyelination methapo ea kutlo, re ile a fumana hore ka tlas'a bohato la macrophages le neurotransmitters (mohlala, interleukins), ke ho senngoa ha myelin, eo le eena ho etsa hore ho senyeha ha methapo ea kutlo matla phetiso le phytoteratology litakatso tsa methapo ea kutlo hammoho axon ena.

bolwetse ena qholotsa litla neurodegenerative: ho senyeha tsa dithulaganyo dikopanothutano, haholo-holo ya memori ho le ho nahana, ponahalo ea ho hloka tšebelisano ea mekhatlo, 'mele le bokgoni bo botle tsa likoloi.

Ka lebaka leo, ho ka khonehang e tletseng bokooa ba ba le mamello, e leng ka lebaka la lefu la autoimmune. Kahoo potso ea kamoo ho ka tsosolosa myelin, ke hona joale ka ho khetheha a hlobaetsang. mekhoa tseo li akarelletsa haholo-holo e leka-lekaneng le protheine-lipid lijo, bophelo kamehla, ho ba sieo ha mekhoa e mebe. Maemong a matla, meriana sebediswa mafu, fokotsa palo ea batho ba holileng tsebong lisele tse glial - oligodendrocytes.