I-Neurons yizona zibhloko zokwakha zesiseko senkqubo. Ezi iiseli ezizodwa ziinkalo zokucwangcisa ulwazi lweengqondo ezijongene nokufumana nokuthumela ulwazi. Icandelo ngalinye le-neuron lidlala indima ekunxibelelaneni ulwazi kuwo wonke umzimba.
I-Neurons ithwala imiyalezo kuwo wonke umzimba, kubandakanywa ulwazi lweengqondo ezivela kwi-external stimuli kunye nemiqondiso evela kwingqondo ukuya kumaqela ahlukeneyo emzimbeni emzimbeni. Ukuze uqonde kakuhle indlela i-neuron esebenza ngayo, kubalulekile ukujonga nganye inxalenye ye-neuron. Izakhiwo ezikhethekileyo ze-neuron zivumela ukuba zifumane kwaye zithumele ezinye iimpawu ze-neurons kunye nezinye iintlobo zeeseli.
Dendrites
Ama-Dendrites afana nezandiso ezifana nomthi ekuqaleni kwe-neuron eyanceda ukwandisa indawo yomzimba weseli. Ezi nxalenye ezincinci zifumana ulwazi oluvela kwamanye ama-neurons kwaye zihambisa ukuvuselelwa kombane kwi-soma. I-Dendrites ihlanganiswe ne-synapses.
Dendrite Iinkcukacha
- Uninzi lwama-neurons luneendidi ezininzi
- Nangona kunjalo, ezinye i-neurons zinokuba ne-dendrite enye kuphela
- Uninzi lufutshane kwaye lubuncinci kakhulu
- Udlulisela ulwazi kumzimba weseli
Uninzi lwama-neurons luneli-extension enjenge-yesebe eliya ngaphandle kwiseli yeseli. La ma dendrites ke afumana iimpawu zamachiza ezivela kwezinye i-neurons, eziguqulwa zibe yimpembelelo kagesi ezithunyelwa kwi-cell body.
Ezinye i-neurons zincinci kakhulu, zincinci, zizezinye iiseli zihlala zide kakhulu. I-neurons yeenkqubo ezisemgangathweni zentlaba zinexesha elide kwaye liyinkimbinkimbi ye-dendrites leyo ifumana iimpawu ukusuka kuninzi nezinye i-neurons eziliwaka.
Ukuba iimpembelelo zombane ezidluliselwa ngaphakathi kumzimba weseli zikhulu ngokwaneleyo, ziya kuvelisa isenzo esinakho. Oku kubangela ukuba uphawu luhanjiswe phantsi kwe-axon.
Funda
I-soma, okanye umzimba weseli, apho izibonakaliso ezivela kwi-dendrites zidibene kwaye zigqityiwe. I-soma kunye ne-nucleus ayidlala indima ebonakalayo ekuhanjisweni kwesiginali se-neural. Kunoko, ezi zimbini zisebenzela ukugcina iseli kunye nokugcina i-neuron isebenzayo.
Iinkcukacha ze-soma:
- Iqukethe amanqaku amaninzi afakwe kwiintlobo zemisebenzi yeseli.
- Iqukethe i-cell nucleus evelisa i-RNA ekhokelela ukuhlanganiswa kwamaprotheni.
- Uncedisa kwaye igcina ukusebenza kwe-neuron.
Cinga ngomzimba weseli njengombane omncinci ovutha i-neuron. I-soma ikhiqiza iiprotheni ukuba ezinye iindawo ze-neuron, kubandakanywa i-dendrites, i-axons kunye ne-synapses, kufuneka zisebenze ngokufanelekileyo.
Iziseko zenkxaso yeseli ziquka i-mitochondria, enika amandla eseli kunye ne-Golgi, izinto ezipakethe ezenziwe yiseli kwaye zizithumela kwiindawo ezahlukeneyo ngaphakathi nangaphandle kweseli.
IAxon Hillock
I-axon hillock ikhona ekupheleni kwe-soma kwaye ilawula ukuqhuma kwe-neuron. Ukuba amandla onke esicatshulwa ngaphaya komda wokungqambela we-axon hillock, isakhiwo siya kutshisa isignali (esaziwayo njengento enokwenzeka ) phantsi kwe-axon.
I-axon hillock yenza njengento yomphathi, ukufaka ubungakanani beempawu ezikhuselekileyo kunye nezithambileyo. Ukuba inani lala manqaku lidlula umyinge othile, isenzo esinokuthi siza kubangela kwaye isalathisi sombane siza kudluliselwa phantsi kwe-axon kude nomzimba weseli. Le nyathelo enokuthi ibangelwa yiinguqu kwiimpawu ze-ion ezichaphazelekayo ngenguqu kwi-polarization.
Kwiimeko eziqhelekileyo zokuphumla, i-neuron ine-polarization yangaphakathi -70mV. Xa uphawu lufunyenwe yiseli, lubangela ion i-sodium ukungena kwiseli nokunciphisa ukuhlengahlengiswa.
Ukuba i-axon hillock iphoxisiwe kwinqanaba elithile, isenzo esinokuthi siza kutshisa kwaye sithumele umqondiso wombane phantsi kwe-axon kwi-synapses. Kubalulekile ukuba uqaphele ukuba isenzo esinokuyenza sisisenzo -nanye-nanye kwaye izibonakaliso azihanjisiwe. I-neurons yomlilo okanye ayifuni.
IAxon
I-axon yi-fiber ehlanganisiwe eqhubekayo ukusuka kumzimba weseli ukuya ekupheleni kokuphela kwaye idlulisela uphawu lwe-neural. Ikhudlwana ububanzi be-axon, ngokukhawuleza idlulisela ulwazi. Ezinye i-axon zihlanganiswe ngento enamafutha ebizwa ngokuthi i-myelin eyenziwa njengesi-insulator. Ezi ngqungquthela ze-myelinated zithumela ulwazi ngokukhawuleza kunezinye i-neurons.
I-Axon Characteristics
- Uninzi lwama-neurons lunexeshana elilodwa kuphela
- Dlulisa ulwazi ngaphandle komzimba weseli
- Ngomhla okanye angenayo i-myelin
I-Axons inokuluhlu ngokubanzi ngokukhulu. Ezinye zifutshane nje njengeimitha ezili-0.1, ngelixa ezinye zingaphezu kwama-3 ubude.
I-myelin ijikeleze i-neurons ikhusela i-axon kunye ne-aid kwisantya sokuhambisa. I-myelin sheath iphulwe ngamaphuzu awaziwa ngokuba ngamanqamu kaRarvier okanye i-myelin. Impembelelo yombane iyakwazi ukuxhuma kwi-node enye ukuya elandelayo, edlala indima ekukhawuleziseni ukuhanjiswa kwesignali.
I-axx zidibanisa namanye amaseli emzimbeni kuquka ezinye i-neurons, iislims muscle kunye nezitho. Ezi zixhumo zivela kwiindibano ezibizwa ngokuba yi-synapses. I-synapses ivumela imiyalezo yamagesi kunye neekhemikhali ukuba idluliselwe kwi-neuron ukuya kwezinye iiseli zomzimba.
Amaqhosha eXesha kunye neeStapap
Amaqhosha okugcina asekupheleni kwe-neuron kwaye ayenaxanduva lokuthumela uphawu kwizinye i-neurons. Ekupheleni kweqhosha lokugcina i-gap eyaziwa njenge-synapse. Ama-neurotransmitters asetyenziselwa ukuthwala umqondiso kwi-synapse kwezinye i-neurons.
Amaqhosha okuphela aquka i-vesicles ephethe i-neurotransmitters. Xa isibonakaliso sombane sifinyelela kumaqhosha okuphela, ama-neurotransmitters ahanjiswa kwi-synaptic gap. Amaqhosha okuphela aguqule iimpembelelo zombane kwiimpawu zamachiza. Ama-neurotransmitters kune-cross cross-synapse apho afunyanwa khona ngamanye amangqamuzana omzimba.
Amaqhosha okuphela aphethwe ngumsebenzi wokuphinda aphinde abuyele kwiprojekiti ekhutshwe ngeli xesha.
ILizwi
I-Neurons isebenza njengeebhloko zokwakha zesiseko se-nervous kwaye zinoxanduva lokuthumela imiyalezo kuwo wonke umzimba. Ukukwazi ngakumbi malunga neendawo ezahlukeneyo ze-neuron kunokukunceda ukuba uqonde ngakumbi ukuba zezi zakhiwo ezibalulekileyo zisebenza njani kunye nokuba iingxaki ezahlukileyo, ezinjengezifo ezichaphazela i-axon ye-myelination, zinokuchaphazela indlela imiyalezo eyaziwa ngayo kuwo wonke umzimba.
> Imithombo:
> Debanne, D., Campana, E., Bialowas, A., Carlier, E., Alcaraz, G. I-Axon physiology. Iingcamango Zengqondo. 2011; 91 (2): 555-602. INGXELO: 10.1152 / i-physrev.00048.2009.
> Lodish, H., Berk, A., & Zipursky, SL, et al. (2000). I-Biology Cell Biology, i-4th edition. ENew York: WH Freeman.
> Squire, L., Berg, D., Bloom, F., du Lac, S., Ghosh, A., & Spitzer, N., eds. (2008). Isiseko senzululwazi ye-Neuro (3rd ed.). I-Press Press.