Mienzaniso yeMibvunzo Inotsanangura Maitiro eNerve Impulse
Maitiro ekufambisa tsinga chikamu chakakosha chetsinga, zvichigonesa kutaurirana pakati pemasero etsinga uye pakati pemasero etsinga nedzimwe nhengo dzemuviri. Kunzwisisa pfungwa iyi kwakakosha pakudzidza nezvefiziyoloji, kungave kuri kwedzidzo yepamutemo, kutsvagisa, kana mashandisirwo anoshanda mubazi rezvehutano. Chinyorwa chino chichafukidza dzidziso yekutanga uye kupa mienzaniso yakati wandei yezvinetso nemhinduro dzekubatsira kunzwisisa kwako maitiro aya.
Pendauluan
Sisitimu yetsinga ine uropi, musana, uye network yetsinga dzinopararira mumuviri wese. Basa rayo guru nderekugamuchira zvinokurudzira, kugadzirisa ruzivo, uye kutumira mirairo kune tsandanyama nemasero. Kufemerwa kwetsinga zviratidzo zvemagetsi zvinogonesa kutaurirana nekukurumidza uye zvinobudirira mukati mesisitimu yetsinga.
Kufungidzira kwetsinga, kana kuti kugona kwekuita, kunokonzerwa nekuchinja kamwe kamwe kwemagetsi pamembrane yesero retsinga (neuron), kunokonzerwa nekufamba kwemaion e sodium (Na+) ne potassium (K+) pamembrane. Maitiro aya anotanga kana neuron ikagamuchira simba rakasimba (rinopfuura mwero wayo), izvo zvinozotanga zviitiko zvakawanda zvemagetsi nemakemikari.
Dzidziso Yekutanga yeNerve Impulse Process
1. Kugona Kuzorora: Kana uropi hukarara, mukati me neuron mune charge isina kunaka kana tichienzanisa nekunze kwayo. Kugona uku kunowanzova -70 mV, zvichienderana nekupararira kwemaion eNa+ neK+ ane Na+ yakawanda kunze kwesero uye K+ mukati mesero.
2. Kubviswa kwepolarization: Kana neuron ikawana kukurudzirwa kwakakwana, nzira dzeNa+ ion dzinovhurika, zvichiita kuti Na+ ipinde musero. Izvi zvinoita kuti mukati mesero muve nepfungwa dzakanaka, uye kana pakasvika mwero, mukana wekuita chimwe chinhu unotanga.
3. Kudzoreredza: Mushure mekunge chiito chasvika padanho repamusoro, nzira dzeNa+ dzinotanga kuvhara uye nzira dzeK+ dzinovhurika, zvichiita kuti K+ ibude musero, zvekuti chaji inodzokera pakuva negative mukati mesero.
4. Hyperpolarization uye Refractory Potential: Dzimwe nguva, kuburitswa kweK+ kunoita kuti membrane potential ive negative kupfuura pakuzorora, kunonzi hyperpolarization. Muchikamu chekuramba, neuron haigone kana kuti inoomerwa zvikuru kutanga chiitiko chitsva.
5. Pombi yeSodium-Potassium: Mushure mekushanda nesimba, pombi iyi inodzosera kugoverwa kwemaion kumamiriro ayo ekutanga nekupomba Na+ kunze uye K+ kudzokera musero.
Mibvunzo yemuenzaniso nekukurukurirana
Mubvunzo 1
Tsanangura kuti simba rekuita rinotangwa sei uye kuti rinopararira sei richifamba netsinga dzeuropi.
Kukurukurirana:
Simba rekuita rinotanga kana neuron ikagamuchira chinhu chakasimba zvakakwana kuti isvike kana kupfuura chiyero chayo che depolarization, icho chinowanzova -55 mV. Kana chiyero ichi chasvika, nzira dze sodium ion dzinonzwa voltage dzinovhurika, zvichiita kuti maNa+ ions afambe nekukurumidza mu neuron. Izvi zvinokonzera depolarization yechikamu ichocho che membrane ye neuron, zvichiita kuti ive yakanaka.
Mushure mekunge depolarization yasvika pakakwirira, nzira dze sodium ion dzinovhara uye nzira dze potassium ion dzinonzwa voltage dzinovhurika, zvichiita kuti kufamba kwema K+ ions kubva mukati me neuron kuenda kunze kuenderere mberi. Maitiro aya anozivikanwa se repolarization, sezvo membrane ichidzokera kune kugona kwayo kwekuzorora kusina kunaka. Kukurumidza kwetsinga kunopararira kuburikidza ne regenerative mechanism iri mu axon, uko maitiro e depolarization uye repolarization anoitika muzvikamu zvakasiyana zve membrane ye neuron.
Mubvunzo 2
Ndeipi basa re refractory potential pakuona divi rekuyerera kwe impulse mu axon ye neuron?
Kukurukurirana:
Simba rekusagona kupindura rine zvikamu zviviri: absolute nere relative relative. Muchikamu chekusagona kupindura, neuron haigone kukurudzirwa kuti igadzire simba idzva rekuita, zvisinei nekuti simba rekukurudzira rakasimba sei. Izvi zvinoitika kana nzira dzeNa+ dzichiramba dzisingashande kunyangwe mushure mekunge depolarization yapera. Munguva yechikamu chekusagona kupindura, simba idzva rekuita rinogona kutangwa, asi rinoda simba rakasimba nekuti membrane inenge yakanyanya kupararira.
Simba rekusagona kupindura (refractory potential) rinokosha pakuona kuti tsinga dzinofamba nenzira imwe chete dzichitevedza axon. Kana chikamu cheaxon chapera simba, chinopinda munguva yekusagona kupindura, zvichidzivirira tsinga kuti dzisadzokere kumashure. Saka, tsinga dzinongofamba dzichienda kuchikamu chinotevera, icho chichiri panzvimbo yekugona kupindura uye hachisati chatanga kushanda. Maitiro aya anoita kuti zviratidzo zvetsinga zviendeswe zvakanaka kuaxon terminal iri pamagumo eneuron.
Mubvunzo 3
Chii chingaitika kana basa repombi yesodium-potassium rikakanganiswa mu neuron? Tsanangura kuti chii chinoitika pakukwanisa kwekuzorora kwemuviri.
Kukurukurirana:
Pombi yesodium-potassium (Na+/K+ ATPase) inoita basa rakakosha mukuchengetedza kugona kwemasero etsinga dzetsinga nekuburitsa maNa+ ions matatu uye maK+ ions maviri musero. Maitiro aya anoda simba kubva kuATP uye anochengetedza gradient yehuwandu iyo inokosha pakushanda zvakanaka kwemasero etsinga.
Kana kushanda kwepombi iyi kukakanganiswa, kupararira kwemaion eNa+ neK+ mukati nekunze kweneuron kuchachinja, neNa+ yakawanda ichiungana mukati mesero uye K+ yakawanda kunze kwesero. Izvi zvinokonzeresa depolarization ye rest potential, zvichiita kuti neuron ive nyore kufemereka kana kutokonzera kutadza kugadzirwa kwe nerve impulse nekuti neuron haigone kudzokera kune rest potential yayo. Uyezve, kusawirirana kwemaion kunogona kukanganisa mashandiro emagetsi emamwe ma neuron uye kunogona kutungamira kumatambudziko akadai se pfari, arrhythmias, kana kumwe kukuvara kwemasero etsinga.
Mhedziso
Kunzwisisa maitiro ekufambisa tsinga kunoda ruzivo rwakasimba rwe physiology ye membrane ye neuronal, kugoverwa kwe ion, uye basa remapuroteni e membrane akadai se ion channels uye sodium-potassium pumps. Kunzwisisa uku kunotibvumira kunzwisisa zviri nani mashandiro e neural uye matambudziko akasiyana-siyana anogona kuitika. Nekudzidzira matambudziko, kunzwisisa kwedu maitiro aya kunogona kusimbiswa, nokudaro zvichitigadzirira zviri nani mibvunzo yedzidzo yeramangwana nemamiriro ekurapa.
