Cns qauv. paj fiber

Paj fiber outgrowth yog ib tug neuron, glial sheath yog coated. Yog vim li cas yog nws tsim nyog? Dab tsi? Yuav ua li cas yog cov qauv? Qhov no koj yuav kawm tau los ntawm qhov tsab xov xwm.

kev faib

Lub fibers ntawm poob siab system muaj ib tug txawv qauv. Nyob rau hauv raws li cov qauv uas lawv yuav ua tau ib ntawm ob hom. Yog li, cais unmyelinated thiab myelinated fibers. Tus thawj muaj ib tug txheej txheem ntawm tes, uas yog nyob rau hauv qhov chaw ntawm lub tsev. Nws yog hu ua ib tug axon (axons). Qhov no tus txheej txheem no surrounded los ntawm ib tug myelin sheath. Muab qhov xwm ntawm tus haumxeeb load siv, tus tsim ntawm paj fibers ntawm ib tug muab hom. Tus qauv ntawm cov lug nyob ntawm lub tuam tsev nyob rau hauv uas lawv muaj nyob rau. Piv txwv li, nyob rau hauv ib tug department Somatic tshee system txheej txheem myelinated paj fibers, thiab vegetative - unmyelinated. Nws yuav tsum tau hais tias tus tsim ntawm cov no thiab lwm yam nram qab no ib tug zoo xws li cov qauv.

Raws li muaj ib tug nyias paj fiber?

Xav txog cov txheej txheem nyob rau hauv ntau yam. Nyob rau theem ntawm tsim ntawm lug xws li unmyelinated axon delves mus rau hauv lub strand muaj lemmotsitov uas tsitolemmy pib sag thiab npog tus txheej txheem rau lub hauv paus ntsiab lus ntawm coupling. Ntug nyob rau hauv no ze li ntawm lub axon, thiab tsim nyob rau duplikatury lub cell daim nyias nyias, uas yog hu ua "mezakson". Lemmotsity, nyob tom ntej no lub qhov rooj, yog tsim nrog kev pab los ntawm lawv cov tsitolemmy yooj yim hu. Unmyelinated fibers vim cov neeg pluag rwb thaiv tsev muaj peev xwm ntawm dua ib tug hlab ntsha lam ua thiab mezaksona cheeb tsam thiab nyob rau hauv lub cheeb tsam ntawm kev sib cuag ntawm lemmotsitami. Raws li ib tug tshwm sim, uas nws kis tau los ntawm ib tug fiber mus rau lwm lub.

Tsim kom muaj tuab lug

Paj fiber myelin tshuam thicker unmyelinated hom. Raws li tus txheej txheem ntawm txoj kev ua zoo li yeej zoo tib yam. Txawm li cas los, cov ceev txoj kev loj hlob ntawm neurons nyob rau hauv lub Somatic department, uas yog txuam nrog rau cov kev loj hlob ntawm lub cev tag nrho, txhawb ncab mezaksonov. Tom qab ntawd lemmotsity qhwv nyob ib ncig ntawm axons ob peb lub sij hawm. Raws li ib tug tshwm sim, lub concentric khaubncaws sab nraud povtseg yog tsim hom, thiab cov tub ntxhais yog tsiv tawm ntawm lub cytoplasm kom kawg kauj, uas yog cov txheej sheath ntawm fiber (neurilemma). Lub puab txheej muaj mezaksona, entwined pheej hu ua myelin. Thaum lub sij hawm, tus xov tooj ntawm koj lem thiab qhov ntev mezaksona maj mam nce. Qhov no yog vim lub tso cai ntawm lub txheej txheem ntawm myelination thaum lub sij hawm axonal txoj kev loj hlob thiab lemmotsitov. Txhua tom ntej lem ntawm lub yav dhau los dav. Qhov tseem kim heev yog ib tug uas muaj lub cytoplasm mus rau lub nucleus lemmotsita. Tsis tas li ntawd, txawv myelin thickness thiab tshaj tag nrho ntev ntawm lub fiber. Nyob rau hauv cov chaw uas lemmotsity kev sib cuag nrog txhua lwm yam, lub stratification disappears. Cov hu nkag mus tsuas yog tus txheej khaubncaws sab nraud povtseg, uas muaj xws li cov cytoplasm thiab nucleus. Tej chaw uas tsim vim lawv tsis muaj kev myelin thinning fiber ntau thiab tus tswv tsev npe interceptions.

Cov kev loj hlob ntawm lug nyob rau hauv lub hauv paus poob siab system

Myelination tshwm sim nyob rau hauv lub system raws li ib tug tshwm sim ntawm kev ntawm oligodendrocytes qhwv axons. Myelin yog ib tug lipid hauv paus thiab nyob rau hauv kev koom tes nrog oxides tau tsaus. Qhov seem Cheebtsam ntawm daim nyias nyias thiab nws interstices nyob twj ywm lub teeb. Cov ib daim hlab yog hu ua notches tshwm sim myelin. Lawv sib haum mus rau lub me me strata nyob rau hauv lub cytoplasm lemmotsita. Ib tug axon nyob rau hauv lub cytoplasm thiab mitochondria neurofibrils cov txheej txheem longitudinally. Lawv loj tshaj xov tooj - los ze zog mus cuam tshuam thiab nyob rau hauv lub kawg li fibers. Tsitolemmy axon (axolemma) yeej txhawb paj lam ua. Nws manifests nws yoj ntawm depolarization. Nyob rau hauv lub rooj plaub uas raws li ib tug axial lub tog raj kheej neurite hais, nws muaj basophilic granules substance.

qauv

Myelinated paj fibers muaj:

1. Axon, uas yog nyob rau hauv qhov chaw.
2. Myelin sheath. Nws yog them nrog lub tog raj kheej axis.
3. Schwann plhaub.

Tam sim no muaj pes tsawg leeg axial lub tog raj kheej neurofibrils. Lub myelin sheath yog muaj li ntawm ib tug plurality ntawm lipoid tshuaj txoj kev myelin. Qhov no kev twb kev txuas muaj zoo tseem ceeb nyob rau hauv lub central lub paj hlwb. Nyob rau hauv kev, nws txiav txim cov kev ceev ntawm uas cov conduction ntawm excitation nyob rau hauv paj fibers. Lub plhaub tsim compound axon kaw li ntawd qag yog tsim, uas yog hu ua ntshav ntawm Ranvier. Nyob rau hauv lawv cheeb tsam ntawm kev sib cuag nrog lub tog raj kheej axis ntawm Schwann sheath. fiber ya - nws kis, uas yog nruab nrab ntawm ob pob hlav ntawm Ranvier. Nws yuav suav hais tias tus tub ntxhais ntawm lub Schwann sheath. Nws yog nyob kwv yees li nyob rau hauv nruab nrab ya. Nws yog surrounded los ntawm cov protoplasm ntawm Schwann hlwb nrog cov ntsiab lus ntawm myelin nyob rau hauv lub loops. Nyob rau hauv nruab nrab ntawm cov ntshav ntawm Ranvier myelin sheath yog tsis homogeneous. Nws muaj oblique notches Schmidt-Lanterman. Schwann cell daim nyias nyias pib tsim los ntawm lub ectoderm. Hauv qab no yog ib tug axon fibers ntawm lub peripheral lub paj hlwb, uas lawv yuav tsum tau hu ua nws cov glial hlwb. Paj fibers nyob rau hauv lub central system devoid Schwann plhaub. Es tsis txhob, muaj cov ntsiab ntawm cov oligodendroglial. Unmyelinated fiber muaj tsuas axons thiab cov Schwann sheath nyob rau hauv nws muaj pes tsawg leeg.

muaj nuj nqi

Lub ntsiab hauj lwm ua los ntawm lub paj fiber - innervation. Qhov no tus txheej txheem yog ntawm ob hom: mem tes thiab bezimpulsnym. Nyob rau hauv thawj cov ntaub ntawv, cov kis tau tus mob tshwm sim los ntawm cov ntsha thiab neurotransmitter mechanisms. Lub innervation plays ib tug luag hauj lwm loj myelin, li ntawd, cov kev ceev ntawm tus txheej txheem yog ho muaj dua nyob rau hauv myelinated fibers tshaj nyob rau hauv unmyelinated. Txheej txheem bezimpulsnogo hom tshwm sim axoplasm tam sim no ntws ntawm tshwj xeeb axonal microtubules, uas comprise trofogeny (tshuaj uas muaj trophic teebmeem).