Qhov sib txawv tseem ceeb ntawm dyad thiab triad leeg yog cov leeg dyad yog cov qauv tam sim no hauv plawv myocyte hauv Z-kab ntawm sarcomere, thaum cov leeg triad yog cov qauv muaj nyob hauv cov leeg pob txha nyob nruab nrab ntawm qhov sib txuas ntawm A thiab kuv. band hauv sarcomere.
Cov txheej txheem hauv daim nyias nyias, transverse tubular system (t-tubule), thiab sarcoplasmic reticulum yog cov kab ke sib cuam tshuam uas cuam tshuam rau cov leeg nqaij fibers thaum lub sij hawm contraction thiab so ntawm cov leeg. Lub t-tubule system yog ib tug branched network ntawm tubules uas khiav transversely hla cov nqaij fibers. Sarcoplasmic reticulum tso calcium ions thaum t-tubules coj sarcolemma los ze zog mus rau sarcoplasmic reticulum los ntawm tag nrho cov cheeb tsam ntawm lub cell. T-tubules yog qhov txuas ntxiv ntawm cov cell membrane uas nkag mus rau hauv nruab nrab ntawm cov pob txha pob txha thiab cov leeg hlwb. Cov leeg lub luag hauj lwm rau contraction yog dyad thiab triad nqaij.
Dyad Muscle yog dab tsi?
A dyad leeg yog cov qauv hauv lub plawv myocyte uas nyob hauv sarcomere Z-line. Nws yog tsim los ntawm ib leeg t-tubule ua ke nrog lub davhlau ya nyob twg cisterna hauv sarcoplasmic reticulum. Cov leeg no yog ib qho tseem ceeb hauv kev ua kom muaj zog thiab kev sib txuas ua ke rau kev ua haujlwm ntawm cov calcium ions. Lub nthwv dej ntawm depolarization yog li ua ke rau calcium-mediated nqaij contraction nyob rau hauv lub plawv los ntawm zawv zawg filament mechanisms.
Daim duab 01: Dyad Cov leeg hauv cov leeg nqaij hlwb
Dyad cov leeg yog ib hom kev sib txuas hauv nruab nrog cev uas xa cov paib excitatory los ntawm plasmalemma mus rau juxtaposed davhlau ya nyob twg cisternae ntawm sarcoplasmic reticulum. Cov qauv thiab kev faib tawm ntawm cov leeg dyad nyob ntawm cov myocyte. Calcium influx los ntawm plasmalemma los ntawm cov khoom muaj peev xwm thaum lub sij hawm systole yog txaus nyob rau hauv me me myocytes xws li embryonic myocardium. Txawm li cas los xij, cov myocytes nyuaj xws li cov neeg laus myocardium xav tau lub zog ntxiv rau kev nkag mus ntawm calcium. Yog li, cytosolic calcium nce yog tsim los ntawm kev tso tawm ntawm calcium ions ntawm dyad cov leeg. Nyob rau hauv cov ntaub so ntswg atrial, uas yog nyias myocytes, dyads muaj nyob rau ntawm myocyte nto, thaum nyob rau hauv cov ntaub so ntswg ventricular, uas yog tuab myocytes, dyads yog tam sim no heev ze rau contractile myofibrils thiab nyob rau hauv myocytes. Nyob rau hauv cov ntaub so ntswg ventricular, lub plasmalemma tsim ib lub network ntawm tubules xa cov cim excitation.
Dab tsi yog Triad Muscle?
Triad leeg yog cov qauv tsim los ntawm t-tubule nrog sarcoplasmic reticulum ntawm ob sab. Triad cov leeg feem ntau yog nyob rau hauv kev sib tshuam ntawm A thiab I band ntawm sarcomere. Triad leeg tsim thiab ua haujlwm ntawm lub hauv paus anatomical ntawm excitation-contraction coupling txoj kev xav, qhov twg ib qho stimulus excites cov leeg thiab ua rau contraction.
Daim duab 02: Triad Muscle
Ib qho kev txhawb nqa xa tawm los ntawm cov kab mob neuromuscular hlws ris raws t-tubules thiab ua kom lub dihydropyridine receptors (DHPRs). Qhov kev ua kom no ua rau muaj qhov tsis txaus ntseeg ntawm kev nkag mus ntawm calcium ions thiab kev sib cuam tshuam ntawm cov calcium conduction ryanodine receptors (RyRs) ntawm sarcoplasmic reticulum uas nyob ib sab. Qhov no, nyob rau hauv lem, pib lub series ntawm cov xwm txheej uas ua rau cov leeg nqaij contraction. Cov leeg nqaij contraction yog tshwm sim los ntawm kev khi ntawm calcium nrog troponin, unmasking qhov chaw khi uas npog cov troponin-tropomyosin complex nyob rau ntawm actin myofilament. Qhov no tso cai rau myosin cross-bridges txuas nrog actin thiab ua rau cov leeg mob.
Dyad thiab Triad leeg zoo sib xws yog dab tsi?
- Dyad thiab triad leeg cov qauv yog tsim los ntawm t-tubule nrog sarcoplasmic reticulum.
- Lawv belongs rau ib hom leeg.
- Ob leeg muaj nuj nqi nyob rau hauv excitation-contraction coupling.
- Ntxiv mus, lawv cov kev ua yog simulated los ntawm calcium ion influx.
Dyad thiab Triad leeg sib txawv yog dab tsi?
Dyad leeg yog cov qauv muaj nyob hauv plawv myocyte nyob rau hauv Z-kab ntawm lub sarcomere, whereas triad leeg yog ib tug qauv nyob rau hauv cov pob txha pob txha nyob rau hauv nruab nrab ntawm lub junctions ntawm A thiab kuv band nyob rau hauv lub sarcomere. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm dyad thiab triad leeg. Dyad cov leeg muaj nyob rau hauv cov leeg nqaij, thaum cov leeg triad muaj nyob rau hauv cov leeg pob txha. Ntxiv mus, dyad cov nqaij ntshiv pab nyob rau hauv lub plawv mob contraction, thaum triad leeg pab nyob rau hauv skeletal nqaij contraction.
Cov hauv qab no qhia txog qhov sib txawv ntawm dyad thiab triad leeg hauv daim ntawv tabular rau ib sab ntawm kev sib piv.
Summary – Dyad vs Triad Muscle
T-tubule system yog ib qho kev sib txuas ntawm cov tubules uas khiav hla hla cov leeg nqaij. Cov leeg lub luag hauj lwm rau contraction yog dyad thiab triad nqaij. Dyad leeg yog cov qauv muaj nyob rau hauv plawv myocyte nyob rau hauv Z-kab ntawm lub sarcomere. Triad leeg yog cov qauv muaj nyob rau hauv cov leeg pob txha nyob nruab nrab ntawm qhov sib txuas ntawm A thiab I band hauv sarcomere. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm dyad thiab triad leeg.
