Qhov sib txawv tseem ceeb ntawm cov ntawm Ranvier thiab internodes yog qhov ntawm Ranvier yog qhov sib txawv ntawm ob lub internodes uas tsis yog insulated, thaum internodes yog ib feem ntawm ib qho axon ntawm ob lub ntawm Ranvier uas tau them nrog myelin.
Cov neuron yog cov qauv tsim thiab kev ua haujlwm ntawm lub paj hlwb. Ib tug raug neuron muaj ntau qhov chaw, suav nrog dendrites, nucleus, cell lub cev, ib qho axon, nodes ntawm Ranvier, internodes, thiab axon terminals. Nerve impulses taug kev raws axons ntawm neurons. Axon yog qhov ntev, nyias, xov zoo li cov qauv ntawm cov neuron. Axons xa impulses mus rau synapses. Axons feem ntau yog them los yog insulated nrog cov hlwb tshwj xeeb hu ua myelin. Myelin qhwv ib ncig ntawm lub axons li myelin sheath. Myelinated ntu ntawm ib qho axon yog hu ua internodes.
Node of Ranvier yog dab tsi?
Node ntawm Ranvier yog qhov sib txawv ntawm ob lub internodes ntawm ib qho axon. Lawv yog periodic gap nyob rau hauv ib tug insulated axon. Hauv lwm lo lus, nodes ntawm Ranvier tuaj yeem txhais tau tias yog thaj chaw liab qab ntawm axon nyob nruab nrab ntawm internodes. Yog li ntawd, ib qho axon raug nthuav tawm rau cov cheeb tsam extracellular ntawm cov nodes ntawm Ranvier. Nodes ntawm Ranvier tseem hu ua myelin-sheath gaps. Raws li txoj cai, cov ntawm Ranvier yog thaj tsam luv ntawm 1 μm hauv qhov loj.
Daim duab 01: Node of Ranvier
Nodes ntawm Ranvier yog qhov tseem ceeb rau kev ua haujlwm sai thiab ua tau zoo (AP). Yog li ntawd, cov nodes ntawm Ranvier pab txhawb kev ceev nrooj ntawm cov hlab ntsha impulses hauv qee cov hlab ntsha, thiab hom conduction no hu ua s altatory conduction. Cov nodes ntawm Ranvier raug suav hais tias yog qhov tseem ceeb ntawm kev ua kom muaj ntsev nrog myelinated axons. Txhawm rau tsim kom muaj hluav taws xob sai sai, lub axonal plasma membrane ntawm cov leeg ntawm Ranvier muaj qhov siab dua ntawm qhov hluav taws xob-gated Na+ channels. Nyob rau hauv salutatory conduction, paj hlwb impulses dhia los ntawm ib qho ntawm Ranvier mus rau tom ntej ntawm axon. Qhov no ua rau kev nthuav tawm sai thiab muaj txiaj ntsig ntawm kev ua haujlwm hauv cov hlab ntsha myelinated.
Internodes yog dab tsi?
Internodes yog ib feem ntawm ib qho axon ntawm ob lub ntawm Ranvier. Lawv yog nyias ntev myelinated ntu ntawm ib qho axon. Qhov ntev ntawm ib qho internode txawv nyob ntawm qhov axon txoj kab uas hla thiab fiber ntau hom. Qhov ntev ntawm ib qho internode tuaj yeem ncav cuag 1.5 mm ntev. Qhov ntev ntawm internode tuaj yeem hloov pauv qhov nrawm nrawm nrog rau cov paj hlwb.
Daim duab 02: Internodes
Piv rau cov nodes ntawm Ranvier, internodes muaj tsawg theem ntawm voltage-gated sodium ion raws. Myelin sheath nyob rau hauv internodes tsub kom qhov ceev ntawm paj hlwb impulse kis tau tus mob. Txij li thaum muaj myelin sheath qhwv ib ncig ntawm internodes, lub axon tsis raug rau lub extracellular ib puag ncig ntawm lub internodes.
Dab tsi zoo sib xws ntawm Node ntawm Ranvier thiab Internodes?
- Ob leeg ntawm Ranvier thiab internodes yog ntu ntawm cov hlab ntsha axons.
- Internodes yog cov ntu myelinated nruab nrab ntawm cov ntawm Ranvier.
- Ob leeg ntawm Ranvier ntev thiab qhov ntev internode hloov pauv qhov nrawm nrawm raws cov hlab ntsha.
- Lawv muaj ion channels.
Qhov txawv ntawm Node ntawm Ranvier thiab Internodes yog dab tsi?
Qhov sib txawv tseem ceeb ntawm qhov ntawm Ranvier thiab internodes yog qhov ntawm Ranvier tsis muaj myelin thaum internodes raug them nrog myelin. Nodes ntawm Ranvier muaj qhov siab ntawm sodium ion channels piv rau internodes. Tsis tas li ntawd, nyob rau ntawm cov pob txha ntawm Ranvier, ib qho axon raug nthuav tawm rau thaj chaw extracellular, thaum nyob rau hauv lub internode, ib qho axon tsis raug rau lub extracellular ib puag ncig. Yog li, qhov no kuj yog qhov sib txawv tseem ceeb ntawm node ntawm Ranvier thiab internodes. Nodes ntawm Ranvier yog thaj chaw me me ntawm 1-2 micrometer hauv qhov loj me, thaum internodes yog cov ntu nyias nyias uas ntev txog 1.5 hli.
Cov hauv qab no infographic nthuav tawm qhov sib txawv ntawm qhov ntawm Ranvier thiab internodes hauv daim ntawv teev npe rau ib sab ntawm kev sib piv.
Summary – Node of Ranvier vs Internodes
Node ntawm Ranvier yog qhov sib txawv ntawm ob lub internodes ntawm myelinated axon. Lawv tseem hu ua myelin-sheath gaps. Lawv tsis muaj myelin. Ntawm qhov tod tes, internodes yog cov ntu myelinated axon ntawm ob qhov ntawm Ranvier. Node ntawm Ranvier yog nplua nuj nyob rau hauv Na+ channels piv rau internodes. Nerve impulses dhia los ntawm ib qho ntawm Ranvier mus rau tom ntej ntawm axon hauv s altatory conduction. Axon raug nthuav tawm rau hauv ib puag ncig extracellular ntawm cov ntawm Ranvier. Yog li, qhov no qhia txog qhov sib txawv ntawm qhov ntawm Ranvier thiab internodes.
