Maitiro Ekuita Basa Mumasero Etsinga
Mashandiro ekuita ndiwo maitiro akakosha mutsinga dzemuviri anogonesa kutaurirana pakati pema neuron nemamwe masero. Kugadzirwa uye kupararira kwemabasa ekuita ndizvo zvakakosha pakutumira ruzivo, zvichitungamira mukudzora mabasa akasiyana-siyana emuviri. Chinyorwa chino chinotarisa maitiro akaomarara emabasa ekuita mumasero etsinga, tichiongorora matanho uye maitiro ari pasi pemamorekuru.
Nhanganyaya yeZvingangoitika Pakuita
Simba rekuita chinhu chinoshanduka nekukurumidza uye kwenguva pfupi musimba remagetsi re neuron. Kubviswa kwepolarization, kuyerera kwema ions ane positive charged, kunoteverwa nekudzorerwa kwepolarization, kubuda kweaya ma ions, zvichidzoreredza mamiriro ekuzorora kwe neuron. Kutenderera kwekuregererwa kwepolarization uye kudzorerwa kwepolarization kunovimbisa kutapurirana kwezviratidzo zve neural munzvimbo refu pasina kurasikirwa nesimba.
Kugona Kwekuzorora kweMembrane
Kuti unzwisise simba rekuita, munhu anofanira kutanga ne simba rekuisa membrane, rinowanzoita -70 millivolts (mV) muma neuron. Simba iri rinochengetwa kuburikidza nekuenzana kwemaion, kunyanya sodium (Na^+) ne potassium (K^+). Kugona kwekuisa membrane mumasero uye kushanda kwe sodium-potassium pump (Na^+/K^+ ATPase) zvakakosha pakuchengetedza simba iri.
Pombi yesodium-potassium inofambisa maNa^+ ions matatu kubva musero uye maK^+ ions maviri kuenda musero, zvichipesana nemazinga awo ekuwanda. Izvi zvinogadzira kuwanda kweNa^+ kunze kwesero uye kuwanda kweK^+ mukati mesero, zvichikonzera kuti negative charge iri mukati me neuron ibude.
Kutanga Kwechiito Chinogona Kuitwa
Mashandiro ekuita anowanzo tangwa pa axon hillock, nzvimbo iyo muviri wesero unoshanduka kuita axon. Kana neuron ikagamuchira stimulus, kuburikidza nemakemikari kana kuburikidza nezvinokonzera zvekunze, nzira dze ion dzine ligand dzinovhurika, zvichiita kuti ma Na^+ ions apinde musero. Kana stimulus yakasimba zvakakwana kuti ibvise polarize membrane kusvika padanho repakati (anenge -55 mV), nzira dze Na^+ dzine voltage dzinovhurika, zvichikonzera kupinda nekukurumidza kwema Na^+.
Kubvisa polarization
Kubvisa polarization ndiyo chikamu chekutanga chesimba rekuita. Kana muganho wasvika, nzira dzeNa^+ dzinovhurika nekukurumidza, uye maion eNa^+ anozadza musero nekuda kwe electrochemical gradient. Kupinda uku kunoita kuti simba re membrane rive rakanaka, richisvika pa +30 kusvika +40 mV. Chikamu chekubvisa polarization chinokurumidza, chinongotora ma millisecond mashoma chete.
Peak uye Repolarization
Pakusvika kwesimba rekuita, mageti ekudzima eNa^+ channels anovharika, zvichimisa kupinda kwemaions eNa^+. Zvadaro, maions eK^+ ane voltage anovhurwa, zvichiita kuti maions eK^+ abude musero. Kubuda kweK^+ kunoita kuti simba remembrane rive rakaipa, zvichiita kuti sero ridzokere pariri pariri.
Hyperpolarization
Mushure mekudzokororwa kwemasero, dzimwe nguva simba re membrane rinova rakaipa kupfuura simba rekuzorora, mamiriro anozivikanwa se hyperpolarization. Izvi zvinoitika nekuti nzira dzeK^+ dzinononoka kuvhara, zvichiita kuti K^+ ibude zvakanyanya. Hyperpolarization inoita kuti ma neuron asakwanise kutangazve rimwe simba rekuita zvinhu nekukurumidza.
Refractory Nguva
Nguva mbiri dzinoramba dzichiita kuti zviito zvinopararira nenzira imwe chete uye dzinochinja mafambiro adzo:
1. Nguva Yekusateerera Mutemo: Munguva iyi, hapana chimwe chinhu chinogona kuitwa, zvisinei nekuti chinokurudzira chakasimba sei. Izvi zvinoenderana nenguva iyo nzira dzeNa^+ dzisingashande.
2. Nguva yeRelative Refractory: Izvi zvinotevera nguva yekusagadzikana kwese apo chinhu chinosimudzira chakakwirira kupfuura zvakajairika chinogona kutanga imwe simba rekuita. Izvi zvinoenderana nenguva iyo nzira dzeK^+ dzinoramba dzakavhurika, uye membrane yacho inenge yakawedzera polarized.
Kuparadzirwa kweAction Potential
Kana yangogadzirwa, simba rekuita rinopararira richitevedza axon. Izvi zvinoitwa kuburikidza nekuvhurwa nekuvharwa kwenzira dzeNa^+ neK^+ dzakavharirwa nevoltage pamwe chete nemembrane. Muma axon ane myelinated, kuvapo kwema myelin sheaths—anodzivirira mafuta anogadzirwa nemasero eSchwann mu peripheral nervous system uye oligodendrocytes mu central nervous system—kunoita kuti saltatory conduction ifambe. Action potentials “inosvetuka” pakati pema nodes eRanvier (mipata iri mu myelin sheath) uko kuwanda kwema voltage-gated channels kwakakwira, zvichiwedzera zvakanyanya kumhanya kwe conduction.
Synaptic Transmission
Kana simba rekuita rikasvika pa axon terminal, rinotanga kuburitswa kwema neurotransmitters mu synaptic cleft kuburikidza ne exocytosis. Machiteshi e calcium (Ca^2+) ari mu axon terminal membrane anovhurika nekuda kwe depolarization, zvichibvumira ma Ca^2+ ions kuti ayerere mu cell. Kupinda kwe Ca^2+ kunoita kuti synaptic vesicles isanganiswe ne presynaptic membrane, zvichiburitsa ma neurotransmitters mu synaptic cleft.
Ma neurotransmitter aya anobva abatana nema receptors ari pa postsynaptic membrane, zvichitanga mhinduro mu postsynaptic cell. Mhinduro iyi inogona kuva yekumutsa kana kudzivirira, zvichienderana nerudzi rwe neurotransmitter ne receptor zvirimo.
Kukosha kweMaitiro Ekuita Anogona Kuitwa
Maitiro ekuita zvinhu zvakakosha pakushanda zvakanaka kwetsinga. Izvi ndizvo zvinotungamira kumabasa akasiyana-siyana kubva pakusunga tsandanyama kusvika pakuona zvinhu zvinokurudzira kunzwa, kudzidza, kurangarira, uye kunyange kuchengetedza mabasa emuviri akakosha akadai sekurova kwemoyo nekufema. Kukanganiswa kwemaitiro ekuita zvinhu kunogona kukonzera matambudziko etsinga, zvichiratidza kukosha kwekunzwisisa maitiro aya ekufambira mberi mune zvehutano.
mhedziso
Simba rekuita chinhu chakakosha pakutaurirana kwetsinga, kusanganisira kubatana kwakaoma kwenzira dzeioni, shanduko dzesimba remembrane, uye kutapurirana kwesynaptic. Kunzwisisa basa reioni, matanho esimba rekuita, uye nzira yekuparadzira zvinopa ruzivo rwekushanda kwetsinga. Ruzivo urwu harungori rwakakosha chete pakurapa zvirwere zvetsinga uye kuvandudza ma network etsinga dzekugadzira muchina.
