Dendrites - dab tsi yog qhov no? Qauv thiab muaj nuj nqi dendridov

Tshee cov ntaub so ntswg muaj li ntawm neurons thiab glia, ua ib tug series ntawm cov feem ntau complex thiab tseem ceeb functions: nws emits faint hluav taws xob impulses, uas yog ces kis tau mus rau cov nqaij ntshiv thiab cov nqaij ntawm cov tib neeg los yog vertebrate tsiaj. Lub hlwb ntawm no cov ntaub so ntswg yog ntawm tshwj xeeb tsa. Nws muab ob qhov tshwm sim ntawm excitation thiab inhibition, thiab lawv siv. Nyob rau hauv neuroscience muaj cov nram qab txhais: dendrites - nws dab ntawm paj hlwb uas tau perceive thiab kis cov ntaub ntawv rau lub neuron lub cev. Nyob rau hauv daim ntawv no peb yuav kawm txog tam sim no cov tswv yim hais txog cov kis mechanisms ntawm paj impulses nyob rau hauv lub loj qhov chaw ntawm poob siab system: lub paj hlwb thiab tus txha caj qaum, raws li zoo raws li kawm cov qauv ntawm cov dendrite, raws li ib tug ntawm lub Cheebtsam ntawm neurocytes.

Rau no peb xav txog nyob rau hauv ntau yam cov qauv ntawm cov kev neuron, uas yog lub hauv paus ntawm lub paj hlwb cov ntaub so ntswg.

Raws li neurocyte qauv txuam nrog nws cov kev khiav dej num

Electron me me kev tshawb fawb txoj kev tau paub tseeb hais tias cov heev tshwj xeeb thiab complex ntaus ntawv qhib lom system, npe hu ua paj ntawm tes. Nws comprises ib lub cev (Soma), ib tug ntev povtseg - thiab ib tug plurality ntawm luv luv axon ntoo. Txhua yam ntawm lawv yog kev cob cog rua nrog lub cytoplasm ntawm lub cell lub cev. Qhov no dendrite. Tus qauv thiab cov tsos ntawm cov sau ua ib pawg ntawm luv luv dab reminiscent ntawm lub crown ntawm tsob ntoo. Raws li nws lub cev ntawm lub neuron los ntawm ib tug synapse tau txais bioelectric potentials los ntawm lwm yam paj hlwb.

Morphology thiab hom

Raws li niaj hnub tshawb fawb histology, dendrites - ib tug branched kawg neurocyte tsis tsuas txais, tab sis kuj mus rau kis ntaub ntawv kho nyob rau hauv daim ntawv ntawm cov hluav taws xob impulses, nyob rau hauv ib tug multi-channel system yog anatomically thiab feem interconnected paj hlwb. Lawv muaj loj nyiaj ntawm cov protein-synthesizing organelles - ribosomes. Ib txhia hom ntawm luv luv dab, xws li pyramidal neurocytes, them los ntawm tshwj xeeb lug - spines.

Raws li cov kev faib npaj los ntawm lub Mev neurohistology S. Ramon y Cajal, ob dendrite yuav thim ntawm lub cev ntawm lub paj ntawm tes rau hauv opposite kev qhia (bipolar neurocytes). Yog hais tias ib tug ntau ntawm dendrites, lawv diverge los ntawm lub radial catfish. Qhov no qauv yog cov yam ntxwv ntawm interneurons. Nyob rau hauv lub cerebellar Purkinje hlwb tawm ntawm lub cev appendages neurocyte nyob rau hauv daim ntawv ntawm ib tug kiv cua. Txhua dendrite, uas nws peb-dimensional qauv yog txawv los ntawm lub nyob sib ze ceg ntawm tus nqi ntawm cov hluav taws xob xwb sau nyob saud.

Thaum uas muaj feem xyuam paj branching dab

Lub cev ntawm lub neuron yog ib tug universal kis thiab tau txais nyob rau tib lub sij hawm lom kwv. Volume (tshwj xeeb tshaj yog cov khoom ntaub ntawv) yog ncaj qha proportional rau tus xov tooj ntawm cov khoom paj impulses. Lawv txiav txim siab los ntawm cov neeg kawm ntawv ntawm branching ntawm lub dendritic tsob ntoo. Yog li ntawd, dendrites - nws neurocyte lug uas ua si integrative muaj nuj nqi.

Ntxiv mus, cov txheej txheem ntawm expanding cov kev sib cuag thaj tsam ntawm ib tug hlab ntsha ntawm tes. Ntxiv tib synapse tsim ntawm lub sij hawm tsub kom lub efficiency ntawm tag nrho cov departments li lub paj hlwb thiab tus txha caj qaum, thiab lub paj hlwb raws li ib tug tag nrho.

Tus qauv ntawm lub dendrite

Los ntawm kev kawm me me preparations ntawm paj hlwb peb pom tias feem coob ntawm dab muaj ib tug cylindrical zoo. Lawv nruab nrab txoj kab uas hla yog 0.9 micron. dendrite ntev mas nws txawv nyias li. Piv txwv li, stellate neurons ntawm lub grey teeb meem ntawm lub cerebral cortex yog cov luv luv (tsis muaj ntau tshaj li 200 microns) dendritic tsob ntoo ceg, whereas lub cev muaj zog neuron dab muaj nyob rau hauv pem hauv ntej horn ntawm cov leeg nrob qaum, ntawm qhov kev txiav txim ntawm 2 hli.

Tshwj xeeb kev kawm ntawv - spines tsim nyob rau neurocytes ceg ua rau ib tug loj tus naj npawb ntawm synapses - slotted rooj hu nrog axon, dendrite los yog Soma ntawm lwm neuron. Synapses yuav tsum tau nyob rau hauv lub cev ntawm ib tug dendrite yog hu ua kav los ncaj qha rau nws cov spines. Raws li peb twb paub, dendrites - branched appendages neurocytes muaj peev xwm sawv tau txais stimulation. Kis kuj yuav siv sij hawm qhov chaw nyob rau hauv cov biopotentials siv molecular tshuaj tebchaw - kev sib kho, xws li acetylcholine, los yog GABA. Lub membrane yuav tsum vov lub dendrite kuaj ion raws, xaiv permeable calcium cations, sodium thiab potassium muab kev koom tes nyob rau hauv lub tso cai ntawm lub paj impulses los ntawm cov neuron.

Raws li ntaub ntawv los nyob rau hauv paj hlwb

Thaum lub sij hawm kis tau tus mob ntawm hluav taws xob nqi lwm lub stimulation thiab inhibition, nrog rau ib tug axon thiab dendrites muab kev koom tes. Nws dab lub neuron, uas tsim synapses nrog rau lwm cov ceg ntseeg hauv lub dendritic tsob ntoo ntawm neurocytes. Empirically pom tias dendrites yog outgrowths ntawm lub cell cytoplasm, membrane coated. Nyob rau hauv nws muaj uas tsis muaj zog hluav taws xob impulses - txiav txim potentials.

Tsaug rau lub luv luv dab ib paj cell tau txais thiab hau ob peb txhiab pulses generated synapses. Qhov no tsis yog tsuas muaj nuj nqi ntawm dendrites. Lawv kuj ua thiab muab cov ntaub ntawv los mus rau hauv neurons, uas muab kev cai thiab kev tswj siv los ntawm lub paj hlwb ntawm tag nrho cov nruab nrog cev thiab cov nqaij ntawm tus tib neeg lub cev.