Muaj kwv yees li 206 pob txha hauv tib neeg lub cev, tab sis tsawg tus neeg paub lawv cov qauv thiab nkag siab tias vim li cas lawv thiaj li muaj zog. Tab sis lub luag haujlwm tseem ceeb hauv qhov no yog ua si los ntawm osteon. Cov no yog cov txheej txheem tsim los ntawm cov pob txha ntawm caj dab, tav, vertebrae, thiab lwm yam. Nws muaj lwm lub npe - Haversian system.
qauv pob txha
Tsuas yog vim kev sib koom tes ntawm cov pob txha thiab cov leeg ntawm peb lub cev, peb tuaj yeem txav tau, thiab qhov no yog lawv lub luag haujlwm tseem ceeb. Muaj, ntawm chav kawm, ntxiv ib tug - hematopoiesis, microelement metabolism, cia (rog cia). Lawv feem ntau muaj cov qauv hauv qab no - cov pob txha tshwj xeeb thiab cov tshuaj intercellular, cov txheej txheej (periosteum), thiab cov pob txha pob txha nyob rau sab hauv.
Txhua pob txha muaj ob yam - cov khoom sib cog lus thiab spongy. Thawj yog muab tso rau ntawm qhov chaw nruab nrab, qhov thib ob - nyob rau hauv qhov chaw, thiab muaj cov pob txha crossbars, nyob tsis random, tab sis nyob rau hauv nruj raws li cov sab nraud cuam tshuam rau cov pob txha nyob rau hauv ib cheeb tsam.
Cov pob txha
Kev sib xyaw ntawm cov organic (30-40%) thiab inorganic (60-70%)tshuaj yog ib tug feature ntawm lub cev muaj pes tsawg leeg. Cov tshuaj inorganic muaj xws li ntsev ntawm cov tshuaj sib txawv: calcium phosphate thiab carbonate, magnesium sulfate thiab lwm yam. Tag nrho cov ntawm lawv yaj nyob rau hauv acids, tom qab nws cuam tshuam tsuas yog cov organic tshuaj nyob rau hauv cov pob txha, thiab cov pob txha zoo nkaus li zoo li daim txhuam cev.
Cov rog, mucoproteins, glycogens thiab collagen fibers (sawv cev los ntawm ossein, osseomucoid, elastin) tuaj yeem raug cais tawm ntawm cov organic tshuaj. Yog tias cov pob txha raug hlawv, nws cov duab yuav khaws cia, tab sis nws yuav nkig thiab yooj yim crumble thaum nias.
Nws yog kev sib xyaw ntawm cov khoom sib txawv uas ua rau cov pob txha tawv, muaj zog, tab sis tib lub sijhawm elastic.
Nyob pob txha
Los ntawm qhov sib txawv ntawm cov qauv lawv muab faib ua:
- tubular. Muaj qhov ntev thiab luv. Muaj ob lub epiphyses thiab diaphysis, cov duab yog trihedral lossis cylindrical;
- spongy - muaj feem ntau ntawm cov ntaub so ntswg ncig los ntawm cov khoom siv;
- flat. Lawv yog ob daim hlau tiaj tus, nruab nrab ntawm cov khoom muaj spongy, piv txwv li, pob txha ntawm scapula;
- mixed. Cov pob txha, muaj ob peb feem ntawm ib tug complex zoo li. Lawv txawv ntawm daim ntawv thiab kev ua haujlwm. Piv txwv li, lub thoracic vertebrae muaj peb qhov chaw - lub cev, koov thiab txheej txheem.
Cellular qauv ntawm pob txha
Tom qab tau tshuaj xyuas cov pob txha ntawm cov cellular, peb tuaj yeem paub qhov txawv ntawm peb lub ntsiab ntawm cov hlwb uas txawv hauv cov qauv thiab ua lawv txoj haujlwm:
- Osteoblasts yog cov menyuam yaus loj,uas yog mesenchymal keeb kwm. Cylindrical zoo, cov tub ntxhais yog nyob eccentrically. Txhua lub xov tooj muaj cov txheej txheem los tiv tauj cov neeg nyob sib ze osteoblasts. Lub luag haujlwm tseem ceeb yog los tsim cov tshuaj intercellular thiab ua lub luag haujlwm rau nws cov mineralization.
- Osteocytes yog theem tom ntej ntawm kev txhim kho cov pob txha pob txha, lawv pom nyob rau hauv cov pob txha uas twb tsis tau tsim. txawm nyob rau hauv tib lub pob txha. Lub hauv paus tseem txo qis hauv qhov loj thiab ua kom tuab dua. Lub xovtooj ntawm tes zoo li yog phab ntsa hauv cov khoom siv hauv nruab nrog cev (lacunae).
- Osteoclasts yog cov hlwb loj uas tuaj yeem loj dua 80 microns loj. Lub nuclei tsis yog ib qho, tab sis ob peb, vim lawv tau tsim los ntawm ob peb macrophages uas tau sib koom ua ke. Txij li thaum lub osteoclast nyob rau hauv tas li ntawd, nws cov duab yog tas li hloov. Nyob rau sab ntawm cov pob txha uas yuav tsum tau muab pov tseg, muaj ntau txheej txheem ntawm lub cell uas zoo li "resorb" cov pob txha, noj tag nrho cov ntsev los ntawm nws thiab rhuav tshem lub matrix.
Cov peb hom hlwb no, ua ke nrog cov teeb meem amorphous thiab ossein fibers nyob rau hauv qhov chaw dawb, raug txiav txim thiab tsim daim hlau, uas dhau los ua osteons, intercalary thiab dav daim hlau.
qauv pob txha
Lub diaphysis muaj ob lub qauv: Haversian system, lossis osteon, yog qhov tseem ceeb - thiab cov ntawv ntxig. Cov qauv ntawm osteon yog complex heev. Cov pob txhadov rau hauv cylinders ntawm txawv diameters. Cov thooj voos kheej kheej no nyob hauv ib leeg, thiab hauv nruab nrab muaj lub npe hu ua Haversian channel. Cov hlab ntsha thiab cov hlab ntsha hla lub kwj dej no.
Osteon tsis yog ib chav tsev sib cais, nws pheej rov ua anastomoses ntawm lwm chav nyob, nrog rau cov periosteum thiab cov hlab ntsha ntawm cov pob txha pob txha. Tom qab tag nrho, cov ntshav ntawm tag nrho cov osteons originates precisely los ntawm lub circulatory network ntawm lub periosteum, thiab ces nkag mus rau hauv cov hlab ntsha ntawm cov pob txha pob txha. Nerve endings khiav parallel mus rau cov hlab ntsha.
Ib qho osteon nyob, daim duab lees paub ntawm qhov no, hauv cov pob txha tubular sib npaug mus rau sab ntev, thiab hauv cov pob txha spongy - perpendicular rau lub zog ntawm compression thiab ncab.
Txhua pob txha yog tsim los ntawm nws tus kheej cov naj npawb xws li osteon, biology justifies xws li qauv los ntawm qhov tseeb hais tias lub load ntawm txhua tus ntawm lawv txawv. Lub femur yog raug rau ib tug loj compressive load thaum taug kev, tus naj npawb ntawm Haversian systems nyob rau hauv nws yog 1.8 pcs. ib square millimeter. Ntxiv mus, 11% yog qhov sib koom ntawm Haversian channels.
Osteons ib txwm sib cais los ntawm cov phiaj nruab nrab (lawv kuj hu ua intercalary). Qhov no tsis muaj dab tsi ntau tshaj li cov pob txha osteon puas lawm uas tau dhau los siv tsis tau rau ib qho laj thawj lossis lwm qhov. Tom qab tag nrho, cov txheej txheem ntawm kev puas tsuaj thiab kev tsim kho tshiab Haversian systems yog tas li mus rau hauv cov pob txha.
Osteon functions
Cia peb teev cov haujlwm ntawm osteon:
- lub tsev thaiv pob txha pob txha;
- muab lub zog;
- tiv thaivpaj ntaub xaus thiab cov hlab ntsha.
Nws paub meej tias osteon yog ib qho qauv uas ua ib lub luag haujlwm tseem ceeb hauv peb txoj kev txav mus los, yog tsis muaj nws lub cev pob txha ua tsis tau raws li nws lub hom phiaj - los txhawb lub cev, cov ntaub so ntswg thiab lub cev hauv qhov chaw.
