The myelin mumuhara tsinga fibers: shanda kupora

Tsinga wemunhu uye vertebrates vane chete STRUCTURAL kuronga uye akapa muzinda - uropi uye musana, uye peripheral mativi - pakukoka kubva nechepakati miviri tsinga, inomiririra pezvakaitwa masero etsinga - Tutsinga tunofambisa mashoko utwu.

Avo akatarwa nezvimiro Neural zvinyama, chikuru mashandiro chiri excitability uye conductivity. ehupfumi izvi zvinotsanangurwa payo zvose STRUCTURAL zviri neuronal membranes vavo zvinoshandiswa, zvinosanganisira imwe pfuma inonzi myelin. Munyaya ino tichakurukura marongerwo uye mashandiro remubatanidzwa ichi, uyewo tione zvichibvira nzira kuti vaigadzirise.

Sei neurocytes uye pezvakaitwa nokufukidzwa myelin

Haasi masanga axons uye dendrites vane runodzivirira zvinosanganisira lipid-mapuroteni zvivako. Chokwadi kuti tsika chinhu biophysical chichiitwa, iyo inobva simba magetsi nomunhu. Kana magetsi anoenda kuburikidza waya, yokupedzisira inofanira kufukidzwa insulating zvinhu yokuderedza bongozozo pakati magetsi pulses uye kudzivirira kuderera amperage. Zvakafanana Unoshanda etsinga faibha anotakura myelin mumuhara. Uyezve, anotsigira, uye inopa internet zvokudya.

Makemikari anoumba myelin

Kufanana vakawanda Sero membranes, ndiko lipoprotein hunhu. Uyezve, mafuta kugutsikana chaizvo - kusvika 75%, uye mapuroteni - 25%. Myelin riri shoma zvakare unotora glycolipids uye glycoproteins. makemikari anoumba Its yakasiyana mune musana uye cranial tsinga.

Pakutanga pane mukuru zviri phospholipids - kusvika 45%, uye vamwe kunobva remafuta akawandisa uye cerebrosides. Demyelination (i.e. myelin wokutsiva zvimwe zvinhu muzvirongwa tsinga) kunotungamirira zvakakomba autoimmune zvirwere zvakadai, zvakadai nemultiple sclerosis.

Kubva makemikari nemaonero, iri raizoda seizvi: zviri myelin mumuhara tsinga fibers kuchinja mamiriro ayo, izvo anonyanya richiratidzwa ari vasanyanye chikamu lipid tigutsikane pachinhu mapurotini. Uyezve kudzikira uwandu remafuta akawandisa uye yakawedzera mvura kugutsikana. Uye izvi zvose zvinotungamirira zvishoma nezvishoma yaitsiva myelin ine oligodendrocytes kana Schwann masero ari macrophages, astrocytes uye intercellular zvokunwa.

Mugumisiro nokukanganisika kuchinja izvi ichava unopinza kuderera mano axons kuita kugadzikana kusvikira zvizere ichivharira pakati kwemutemo etsinga nomunhu.

Features neuroglial masero

Sezvambotaurwa, kune myelin mumuhara kuti axons uye dendrites achiumbwa chaizvo zvivako, dzinoratidzwa vakaderera kuti permeability nokuda yavaibvisa uye calcium yakawanda ions, uye naizvozvo ndine chete nekuzorora potentials (havagoni kuitisa tsinga nomunhu uye kushandisa zvemagetsi shanda).

zvivako izvi zvinonzi masero glial. Idzi dzinosanganisira:

• oligodendrocytes;
• fibrous astrocytes;
• masero ependymal;
• yeplasma astrocytes.

Vose vari aumba kubva rokunze paiva embryo - the ectoderm uye vane zvakafanana zita - macroglia. Glia tsitsi, parasympathetic uye somatic tsinga anomirirwa Schwann masero (neyrolemmotsitami).

Marongerwo uye basa oligodendrocytes

Ndivo chikamu nechepakati tsinga uye masero macroglia. Sezvo myelin - a puroteni-lipid yakarongeka, izvozvo anowedzera mwero excitation. Masero pachavo iumbe electrically insulating rukoko tsinga harinzwi muuropi uye musana, kuumbwa kare panguva fetus. pezvakaitwa dzavo obvorachivayut mu rayo mipendero plasmalemma Tutsinga tunofambisa mashoko utwu uye dendrites uye axons. Zvakaratidza kuti myelin - kumboenda magetsi insulating zvinhu, delimiting etsinga dzinotsanagura yakavhenganiswa tsinga.

Schwann masero uye mamiriro avo

The myelin mumuhara pamusoro peripheral tsinga maitiro vakaumba neyrolemmotsitami (Schwann masero). Dzavo nevamwe chinhu chine pakuti vanogona kuumba chimwe chete kukudzivirira mumuhara pamusoro axon, uye haigoni kuumba mabukira, sezvo tinoberekwa oligodendrocytes.

Between Schwann masero munharaunda 1-2 mm vanoiswa migove isina myelin, vanonzi nodes pamusoro Ranvier. Maererano naye payakakurudzirwa kunoitika conduction pamusoro nemagetsi nomunhu mukati axon.

Lemmotsity akakwanisa kugadzirisa etsinga fibers, uyewo kuita trophic ushande. Somugumisiro nemagene aberrations lemmotsitov goko masero mitotic dzinotanga dzisingadzorwi kupesana uye kukura, mauri bundu yakatanga munyika dzakasiyana-siyana tsinga - schwannoma (neurinoma).

Basa microglia mukuparadza myelin mamiriro

Microglia anomiririra macrophages vanokwanisa phagocytosis uye kugona akasiyana pathogenic nezvimedu - maantigen. Nemhaka Kamudzira receptors, masero aya glial pave makemikari - proteases uye cytokines, akadai interleukin 1. Iye murevereri kuzvimba uye kudzivirirwa.

The myelin mumuhara, ane basa iri voga axial humburumbira uye uvandudze tsinga zvairatidza anogona akakanganisa interleukin. Somugumisiro, etsinga "pachena" uye kumhanya ari excitation iri yekudyidzana ipfupi.

Uyezve, cytokines, simba receptors vanotsamwisa kunyanya karusiyamu Ion chokufambisa kupinda muviri dzouropi. Rudzi rweprotease uye phospholipase dzinotanga anamatire organelles uye pezvakaitwa masero etsinga, iyo inotungamirira apoptosis - rufu kupiwa mamiriro.

Iye collapses, kupaza nezvimedu, izvo vanoparadza macrophages. Fani iyi inonzi excitotoxicity. Kunoita degeneration pamusoro Tutsinga tunofambisa mashoko utwu vavo harinzwi zvichitungamirira zvirwere zvakadai yeAlzheimer uye hosha yeParkinson.

Myelinated tsinga fibers ose

Kana neuronal pezvakaitwa - dendrites uye axons, kuti myelin mumuhara chifukidzo, dzinonzi myelinated uye innervate skeletal tsandanyama, kupinda somatic weboka peripheral tsinga. Unmyelinated fibers vanoumba nyika autonomic tsinga uye innervated nenyere.

Myelinated pezvakaitwa vane dhayamita yakakura kupfuura vasiri dzine uye kuumbwa sezvinotevera: axons kurerutsa plasma Kamudzira masero glial uye chimiro Linear mezaksony. Zvadaro, ivo kumwezve uye Schwann masero anoramba putira vakakomba axon, dzikaumba concentric akaturikidzana. The cytoplasm uye neerekitironi lemmotsita vakatamira rokunze layer unonzi neurilemma kana Schwann mumuhara.

Yomukati rukoko rine laminate lemmotsita mezoksona inonzi myelin mumuhara. ukobvu kwayo muzvikamu zvakasiyana pamusoro etsinga hakusi chete.

How kudzorera myelin mumuhara

Kufunga basa microglia dziri tsinga demyelination, takazoziva kuti pasi zvinoitwa macrophages uye neurotransmitters (semuenzaniso, mainterleukin), ndiko kuparadzwa myelin, izvo zvinozoita inotungamirira Kushatiswa simba yedzimudzangara Tutsinga tunofambisa mashoko utwu uye havachanyatsogoni tsinga nomunhu munzira axon.

zvokurwara ichi chinokurwadzai neurodegenerative Migumisiro: Kuipa zvishande urongwa, kunyanya kuyeuka uye mafungiro, pakuonekwa kushaya Kufambisa nemafambiro muviri uye nomucheka motokari unyanzvi.

Somugumisiro, zvinobvira azere urema murwere, unova pamusana autoimmune chirwere. Saka mubvunzo sei kudzorera myelin, pari kunyanya chakasimba. Nzira dzakadaro dzinosanganisira kuchikonzerwa nepakati mapuroteni-lipid zvokudya, upenyu dzose, kusavapo tsika dzakaipa. In Muzviitiko zvakaipisisa, mishonga inoshandiswa zvirwere, kuderedza masero vakura glial - oligodendrocytes.