Lub cev muaj zog lossis lub cev muaj zog yog ib pawg ntawm fibers uas yog innervated los ntawm ib lub cev muaj zog neuron. Tus naj npawb ntawm cov fibers suav nrog hauv ib chav yuav txawv nyob ntawm qhov ua haujlwm ntawm cov leeg. Qhov kev txav me me uas nws muab, qhov me me ntawm lub cev muaj zog thiab qhov siv zog tsawg dua nws yuav ua rau nws zoo siab.
Lub cev muaj zog: lawv cov kev faib tawm
Muaj ib qho tseem ceeb hauv kev kawm txog lub ncauj lus no. Muaj cov txheej txheem uas txhua lub cev muaj zog tuaj yeem ua tus yam ntxwv. Physiology raws li kev tshawb fawb paub qhov txawv ntawm ob yam:
- nrawm ntawm kev cog lus hauv kev teb rau impulse conduction;
- qaug nrawm.
Raws li, raws li cov ntsuas no, peb hom lub cev muaj zog tuaj yeem paub qhov txawv.
- Slow, tsis nkees. Lawv lub cev muaj zog neurons muaj ntau myoglobin, uas muaj kev sib raug zoo rau oxygen. Cov leeg nqaij uas muaj ntau lub cev muaj zog qeeb hu ua liab vim lawv cov xim tshwj xeeb. Lawv tsim nyog los tswj tus neeg lub cev thiab ua kom nws sib npaug.
- nrawm, nkees. Cov leeg no muaj peev xwm ua tau ntau qhov contractions hauv lub sijhawm luv luv. Lawv cov fibers muaj ntau cov khoom siv zog, los ntawm cov ATP molecules tuaj yeem tau siv oxidative phosphorylation.
- nrawm, qaug zog tiv taus. Cov fibers no muaj ob peb mitochondria, thiab ATP yog tsim los ntawm kev tawg ntawm cov piam thaj molecules. Cov leeg no hu ua dawb vim lawv tsis muaj myoglobin.
Units ntawm thawj hom
Lub cev muaj zog ntawm thawj hom lossis qeeb qeeb, pom feem ntau hauv cov leeg loj. Xws li motoneurons muaj qhov pib qis ntawm excitation thiab ceev ntawm cov hlab ntsha impulse. Cov txheej txheem hauv nruab nrab ntawm cov paj hlwb cov ceg hauv nws lub davhlau ya nyob twg thiab innervates ib pawg me me ntawm fibers. Qhov zaus ntawm kev tawm mus rau qeeb lub cev muaj zog yog los ntawm rau txog rau kaum impulses ib ob. Lub cev muaj zog neuron tuaj yeem tswj tau qhov kev sib dhos no rau ntau kaum feeb.
Lub zog thiab nrawm ntawm kev cog lus ntawm lub cev muaj zog ntawm thawj hom yog ib thiab ib nrab zaus tsawg dua li ntawm lwm hom ntawm lub cev muaj zog. Yog vim li cas rau qhov no yog qhov tsawg ntawm ATP tsim thiab tso tawm qeeb ntawm calcium ions mus rau sab nrauv cell membrane rau khi rau troponin.
Units ntawm hom thib ob
Lub cev muaj zog ntawm hom no muaj lub cev muaj zog loj neuron nrog tuab thiab ntev axon uas innervates ib pob loj ntawm cov leeg nqaij. Cov paj hlwb no muaj qhov siab tshaj plaws ntawm kev zoo siab thiab qhov siab tshaj plaws ntawm cov hlab ntsha impulses.
Ntawm qhov siab tshaj plawscov leeg, qhov zaus ntawm cov hlab ntsha impulses tuaj yeem ncav cuag tsib caug ib ob. Tab sis lub cev muaj zog neuron tsis muaj peev xwm tswj tau qhov ceev ntawm conduction rau lub sijhawm ntev, yog li nws tau nkees sai. Lub zog thiab ceev ntawm kev cog lus ntawm cov leeg nqaij fiber ntau ntawm hom thib ob yog siab dua li ntawm yav dhau los, txij li tus naj npawb ntawm myofibrils hauv nws ntau dua. Fiber muaj ntau cov enzymes uas zom cov piam thaj, tab sis tsawg dua mitochondria, myoglobin protein thiab cov hlab ntsha.
Thib peb units
Lub cev muaj zog ntawm hom thib peb yog hais txog kev ceev, tab sis qaug zog-resistant nqaij fibers. Raws li nws cov yam ntxwv, nws yuav tsum tuav tus nqi nruab nrab ntawm thawj hom ntawm lub cev muaj zog thiab qhov thib ob. Cov nqaij ntshiv ntawm cov leeg nqaij no muaj zog, ceev thiab tawv. Lawv tuaj yeem siv ob txoj hauv kev aerobic thiab anaerobic kom rho tawm lub zog.
Qhov piv ntawm cov fibers ceev thiab qeeb yog kev txiav txim siab ntawm caj ces thiab yuav txawv ntawm ib tus neeg mus rau lwm tus. Tias yog vim li cas ib tug neeg yog qhov zoo ntawm kev khiav deb, ib tug neeg yooj yim kov yeej txoj kev sprint puas meters, thiab ib tug neeg yog ntau haum rau weightlifting.
Strech reflex thiab lub cev muaj zog neuron pas dej
Thaum ncab ib qho nqaij, cov fibers qeeb yog thawj zaug. Lawv cov neurons hluav taws mus txog kaum pulses ib ob. Yog hais tias cov nqaij ntshiv txuas ntxiv, ces qhov zaus ntawm cov impulses generated yuav nce mus rau tsib caug. Qhov no yuav ua rau muaj kev sib cog lus ntawm peb hom ntawm lub cev muaj zog thiab ua kom lub zog ntawm cov leeg tenfold. Ntawmntxiv stretching yuav txuas lub cev muaj zog fibers ntawm ob hom. Qhov no yuav muab lub zog ntawm cov leeg los ntawm plaub mus rau tsib zaug.
Lub cev nqaij daim tawv yog tswj los ntawm lub cev muaj zog neuron. Cov txheej txheem ntawm cov hlab ntsha uas ua rau ib leeg yog hu ua lub cev muaj zog neuron pas dej ua ke. Ib lub pas dej ua ke tuaj yeem muaj cov neurons ib txhij los ntawm cov txiaj ntsig sib txawv thiab ntau qhov tshwm sim ntawm lub cev muaj zog. Vim li no, ntu ntawm cov leeg nqaij fibers tsis tau qhib tib lub sijhawm, tab sis raws li qhov nro thiab ceev ntawm cov hlab ntsha impulses nce.
Principle of magnitude
Lub cev muaj zog ntawm cov leeg, nyob ntawm nws hom, kev cog lus tsuas yog thaum muaj qee qhov kev thauj khoom mus txog. Qhov kev txiav txim ntawm excitation ntawm lub cev muaj zog units yog stereotypical: thawj, me me lub cev muaj zog neurons cog lus, ces paj hlwb impulses maj mus txog loj sawv daws yuav. Cov qauv no tau pom nyob rau hauv nruab nrab ntawm lub xyoo pua nees nkaum los ntawm Edwood Henneman. Nws hu nws tias "tus thawj coj ntawm qhov loj."
Brown thiab Bronk ib nrab xyoo ua ntej tshaj tawm lawv cov haujlwm ntawm kev kawm txog lub hauv paus ntsiab lus ntawm kev ua haujlwm ntawm cov leeg nqaij ntawm ntau hom. Lawv tau hais tias muaj ob txoj hauv kev los tswj kev sib cog lus ntawm cov leeg nqaij. Thawj ntawm lawv yog txhawm rau nce qhov zaus ntawm cov hlab ntsha impulses, thiab qhov thib ob yog kom koom nrog ntau lub cev muaj zog neurons li sai tau hauv cov txheej txheem.
