Ke myelin wahi o nā aʻalolo olona,: kuleana pili i ke ola

ʻO ko mākou hopohopo nenoaiu o ka ke kanaka a me ka vertebrates i ka hookahi mall kumumanao, a hooku iho la ia i ka waena konu - o ka lolo a me ka spinal kaula, a me kaʻike ākea māhele - e holo ana mai ke kino Central o na nā aʻalolo, i ho i keʻano o ka hanaʻana o nā aʻalolo keena - neurons.

Lākou i ano neural'aʻaʻa, i ke kumu nui mana o ka i mea excitability a me ka conductivity. I kŰia mau mea i wehewehe ia ma luna o nā mea a pau i ka mall hiʻona o neuronal membranes a me kā lākou mau appendages, oia hoi o ka waiwai a pau i kapaia myelin. Ma kēia 'atikala, e nānā i ka' ole a me ka hana ana o keia hui mākou, e like me ka pono i loaʻa mai i hiki aoao, e hoʻihoʻi aku ia.

No ke aha la neurocytes a me keʻano o ka hanaʻana uhi ma myelin

He ole coincidence axons a me dendrites i ka aiiay, ahu iho iloko olaila o ka lipid-kumuʻiʻo eiiieaenu. Ka nui, e hoike ana i ke kula o ka biophysical kaʻina hana, a ua muli ma ka nawaliwali pou impulses. I ka uila au i hele ma ka uea, pono e uhi mai i ka la mahope me ka hō'īpale mea e emi i ka dissipation o ka pou lāʻau ikiʻai wale, a i ole emi ma ka amperage. Na ia mau hana i loko o ke aʻalolo puluniu hāpai i ka myelin wahī. A eia hoi, ka mea, o ke kākoʻo, a me hoakaka i ka puluniu ai.

Ke Nine Inch haku mele 'ana o ka myelin

Like loa aeea membranes, ia mea he lipoprotein ano. A, momona maʻiʻo ka loa kiʻekiʻe - mai i 75%, a me ka kumuʻiʻo - 25%. Myelin ma ka liʻiliʻi dala i maupaʻa glycolipids a me glycoproteins. Kona Nine Inch haku mele 'ana mea okoa ma ka spinal a me ka cranial nā aʻalolo.

Ma mua, aia no he maʻiʻo kiʻekiʻe o phospholipids - i ia 45%, a me ke koena mai, mai naʻokoko a me cerebrosides. Demyelination (a laila myelin hope no nā 'ona i loko o nā aʻalolo keʻano o ka hanaʻana) hiki aku ai i ka loa autoimmune maʻi, e like me mau sclerosis.

Mai ka Nine Inch wahi o ke hoomaopopo, i kēia kaʻina makemake nana me keia: ka myelin wahi o nā aʻalolo olona, hoʻololi kona 'ole, a ua kuhikuhi hoikeia ma ka emi i loko o ka pakeneka o lipid ka maʻiʻo ma ka pili ana i nā polokina. Eia ka hōʻemiʻana i ka nui o ka naʻokoko, a mahuahua ka wai maʻiʻo. A pau i kēia hiki aku i ka holo hope o ka myelin i loaʻa ka oligodendrocytes a Schwann keena ma macrophages, astrocytes a me intercellular wai.

I ka hopena o kēia mau biochemical loli, e ia iʻoi emi i loko o ka hiki ana o axons, e hoʻomaka manaʻo pīhoihoi a piha wahi o ka hooholo ia ana o nā aʻalolo impulses.

Hiʻona neuroglial keena

E like me ua oleloia, o ka myelin wahī o axons a me dendrites ua hanaʻia me ka kūikawā hale, wehewehe aku ma ka haahaa o ka permeability no ka paʻakai, a kalipuna Ion, a no ia mea, ua kau mai ana iluna wale Loaʻaʻia (hiki ole e hoʻomaka nā aʻalolo impulses, a hana uila kuleana pili i).

Mau hale i kapaʻia glial keena. Mau nā:

• oligodendrocytes;
• fibrous astrocytes;
• ependymal keena;
• wai koko astrocytes.

A pau o lakou, i hana mai i ka pā, ahu iho o ka embryo - ka ectoderm, a i ka na inoa - macroglia. Glia kōkua aloha, parasympathetic a me ka somatic nā aʻalolo poe Schwann aeee (neyrolemmotsitami).

'Ole a me ka hana ana o oligodendrocytes

Ka mea, i kekahi hapa o ka Central ko mākou hopohopo'ōnaehana a ua macroglia keena. No ka mea, myelin - he kumuʻiʻo-lipid 'ole, ka mea maoli i ka uku o ka excitation. Ke keena lakou ia lakou iho i hana i ka uila hō'īpale papa o nā aʻalolo a hāʻule pahū wale i loko o ka lolo a me ka spinal kaula, ua hana oia ano ma fetal ulu. Lākou mau keʻano o ka hanaʻana i loko o obvorachivayut kona mawaho loko o ka plasmalemma neurons a me dendrites a me axons. Ua huli mai i ka myelin - ka hoʻokumu paʻa uila hō'īpale mea, delimiting ke aʻalolo keʻano o ka hanaʻana o ka hui nā aʻalolo.

Schwann keena a me kā lākou mau hiʻona

Ke myelin wahi o kaʻike ākea nā aʻalolo'ōnaehana i hana neyrolemmotsitami (Schwann aeee). Lākou kiʻiona hiʻona ninoieo ma ka oiaio i ka mea hiki ke hana i kekahi wale aiiay wahi o ka axon, a me ka hiki ole hana hoi e pana aku, e like me ka hoʻomaopop 'ana i loko o oligodendrocytes.

Ma waena o Schwann keena ma ka aina o 1-2 mm o e waiho apana devoid o myelin, no laila,-kapa aka wahi o Ranvier. E like me ia i ho opa ao ia lŘlŘ conduction o ka pou impulses loko o ka axon.

Lemmotsity hiki ke hana hou i ke aʻalolo olona, e like me hana trophic kuleana pili i. E like me ka hopena o aaiaoe aberrations lemmotsitov iwi mitotic keena hoʻomaka i kipi mahele a me ka ulu ana, ai kaʻeho hoʻomohala i loko o nā wahi likeʻole o ka'emi'ōnaehana - schwannoma (neurinoma).

Ke kūlana o nā microglia i loko o ka make ana o ka myelin 'ole

Microglia ho macrophages hiki o phagocytosis, a hiki i ka hoʻomaopopo 'okoʻa pathogenic (particles) - antigens. Mahalo i kaʻili lahilahi receptors, i kēia mau glial keena paka nā'ūhū - proteases a me cytokines, e like me interleukin 1. He mea i ka uwao o ka li nui, a e hoʻonele.

Ke myelin wahi, o kona kuleana pili i ka mea e kaʻawale i e poino ai ka iho paukūʻolokaʻa a me ka hou ana o ke aʻalolo impulse interleukin. E like me ka hopena, ke aʻalolo "waiho i hanau o" a me ka mämä holo o ka excitation ua me ka nui loa hoemiia.

A, cytokines, ho'ā 'ia paha receptors ka hoʻonāukiukiʻana excessive kalipuna ion amo i loko o ke kino o ka neuron. Protease a phospholipase hoʻomaka e hoopili organelles a me keʻano o ka hanaʻana o nā aʻalolo keena, a hiki aku i ka apoptosis - i ka make ana o ka hāʻawi 'ole.

Ua collapses, wawahi i (particles), a hoʻopau iā macrophages. O kŰia ua kapaia excitotoxicity. Ua hoʻololi i nā hana degeneration o neurons a me kā lākou mau a hāʻule pahū wale, e alakai i ka maʻi e like me Alzheimer ka a Parkinson ka maʻi.

Myelinated nā aʻalolo olona, o

Inā neuronal keʻano o ka hanaʻana - dendrites a me axons, ka myelin kona uhi, ua kapaia ka mea, myelinated, a innervate skeletal Muscle, komo i ka somatic mahele o kaʻike ākea ko mākou hopohopo nenoaiu. Unmyelinated olona, nāna i hana i ka autonomic ko mākou hopohopo'ōnaehana a innervated nā loko.

Myelinated keʻano o ka hanaʻana i ka nui anawaena ma mua o ka ole-fleshy, a ua hanaʻia e like me ia mahope iho: axons deflect i ka wai kokoʻili lahilahi o glial keena a me ke ano laina mezaksony. A laila, ka mea, ua o ia mai, a Schwann keena pinepine uhi a puni ka axon, ho okumu i concentric papa. Ke cytoplasm a me ka nucleus lemmotsita hoʻoneʻe i ka pahale mawaho, ahu iho, i ua kapaia neurilemma a Schwann wahī.

Ka loko, ahu iho ninoieo o ka lamineka lemmotsita mezoksona kapa myelin wahī. kona mānoanoa i loko o kekahi mau pauku o ke aʻalolo mea i ka ia.

Pehea e hoihoi i ka myelin wahī

E noonoo pono i ke kūlana o ka microglia i loko o nā aʻalolo demyelination, ua ike ia ma lalo o ka hana ana o macrophages a me neurotransmitters (e laʻa me, interleukins), o ka make ana o ka myelin, i ka huli hele aku ai i ka mea hōʻemi o ka mana EYI neurons a me kaʻole nā aʻalolo impulses ma ka axon.

Kēia pathology hoʻonāukiukiʻana mai o neurodegenerative ole: mea hōʻemi o cognitive keʻano o ka hanaʻana, o ka oi aku hoomanao ana a me ka manaʻo, me ka helehelena o ka nele o ka ōhumu o ke kino a me ka neʻe 'ana o ke olonā i Hawaii mākau.

E like me ka hopena, e hiki ai piha ke kīnā o ke hoomanawanui, i mea no ka hopena o ka autoimmune maʻi. No laila, i ka ninau o ke ana, e hoihoi hou myelin, mea a ianoiyuaa a maopopo huʻi. Oia ki ina hana like nā kuhikuhi i ke koena aku hoi kumuʻiʻo-lipidʻai, regular ola, e kaawale aku ai ka maikaʻiʻoleʻano. I loa hoopii, ka lapaʻauʻia hoʻohana maʻi, hoemi i ka helu o ka oo glial keena - oligodendrocytes.