Cov menyuam yaus lub cev uas ua haujlwm tiv thaiv kab mob thiab hematopoietic - thymus. Vim li cas thiaj hu ua menyuam yaus? Yuav ua li cas rau nws thaum laus? Thiab nws qhov chaw kho mob tseem ceeb yog dab tsi? Koj yuav pom cov lus teb rau cov lus nug no thiab ntau lwm cov lus nug hauv kab lus no.
Lub luag haujlwm ntawm thymus hauv tib neeg lub cev
Thymus ua lub luag haujlwm hematopoietic. Nws txhais li cas? Nws cuam tshuam nrog kev sib txawv thiab kev cob qhia (immunological) ntawm T-lymphocytes. Nws tseem yog ib qho tseem ceeb uas "nco" ntawm lymphocytes ntev heev, thiab yog li ntawd tus me nyuam uas tau mob tib yam kab mob qhua pias yuav tsis mob dua nyob rau hauv 99% ntawm cov neeg mob. Qhov no yog hu ua kev tiv thaiv ruaj khov. Ntxiv nrog rau qhov kev loj hlob thiab kev sib txawv ntawm T-lymphocytes, thymus koom nrog hauv cloning ntawm lub cev tiv thaiv kab mob. Los ntawm txoj kev, kuv xav kom nco ntsoov tias qhov txo qis hauv kev tiv thaiv kab mob rau thymus yog cuam tshuam ncaj qha. Kev txo qis hauv T-lymphocytes ua rau tag nrho cov kev cuam tshuam uas txo qis kev tiv thaiv. Thiab qhov no piav qhia ntau yam hauv kev kho menyuam yaus, thaum, piv txwv li, tawm tsam keeb kwm yav dhau los ntawm qee tus kab mob banal, kis kab mob thib ob lossis kab mob thib ob tshwm sim.
Nyob ntawm no thymustsim ntau yam tshuaj hormones. Cov no suav nrog: thymus humoral factor, thymalin, thymosin, thiab thymopoietin. Cov tshuaj hormones no kuj ua rau lub cev tsis muaj zog.
Thymus: histology, qauv, kev ua haujlwm
Thymus yog ib yam kab mob parenchymal (stroma thiab parenchyma cais nyob rau hauv nws). Yog tias koj saib cov tsos ntawm cov qauv histological ntawm thymus, nws tuaj yeem raug sau tseg tias lub cev yog lobulated.
Txhua lub lobule muaj qhov tsaus ntuj thiab qhov kaj. Hauv kev tshawb fawb, qhov no yog cortex thiab medulla. Raws li twb tau hais lawm, thymus ua haujlwm tiv thaiv kab mob. Yog li ntawd, nws tuaj yeem raug hu ua lub chaw ruaj khov ntawm cov menyuam yaus lub cev tiv thaiv kab mob. Yog li ntawd qhov chaw ruaj khov no tsis poob los ntawm thawj qhov txawv teb chaws protein-antigen uas tuaj hla, koj yuav tsum tsim qee yam kev tiv thaiv rau nws. Thiab xwm tau tsim qhov kev tiv thaiv no, hu ua nws cov ntshav-thymus barrier.
Cov ntsiab lus ntawm histology ntawm thymus barrier
Qhov kev thaiv no yog sawv cev los ntawm lub network ntawm sinusoidal capillaries thiab subcapsular epithelium. Cov kab mob no suav nrog cov kab mob capillary epithelial. Ntawd yog, cov antigens uas tsim los ntawm cov kab mob pathogenic tam sim ntawd nkag mus rau hauv cov hlab ntsha, los ntawm qhov ntawd lawv kis thoob plaws hauv tib neeg lub cev. Lub thymus tsis muaj qhov tshwj xeeb, qhov twg cov antigens tuaj yeem xaus. Lawv yuav mus li cas? Lawv tuaj yeem tau txais los ntawm microvasculature, uas yog, los ntawm cov hlab ntsha. Daim duab hauv qab no qhia txog keeb kwm ntawm kev npaj los ntawm thymus, cov hlab ntsha hauv stroma tau pom meej meej.
Inside the capillary is lined with endothelial cells. Lawv raug them los ntawm lub hauv paus membrane ntawm lub capillary. Nyob nruab nrab ntawm lub hauv qab no daim nyias nyias thiab sab nrauv yog qhov chaw perivascular. Macrophages muaj nyob rau hauv qhov chaw no, uas muaj peev xwm phagocytize (absorb) cov kab mob pathogenic microorganisms, antigens, thiab lwm yam. Hauv qab ntawm daim nyias nyias muaj ntau pua ntawm lymphocytes thiab cov hlwb reticuloepithelial uas tiv thaiv thymus microvasculature los ntawm antigens thiab pathogens.
Thymus cortex
Cov tshuaj cortical muaj ntau cov qauv, piv txwv li, cov no yog cov hlwb ntawm lymphoid series, macrophage, epithelial, txhawb nqa, "Nanny", stellate. Tam sim no cia peb saib ze dua ntawm cov hlwb no.
- Stellate cells - secrete thymic peptide cov tshuaj hormones - thymosin lossis thymopoietin, tswj cov txheej txheem ntawm kev loj hlob, kev loj hlob thiab kev sib txawv ntawm T-cells.
- Lymphoid cells - cov no suav nrog cov T-lymphocytes uas tseem tsis tau loj hlob.
- Txhawb cov hlwb - tsim nyog los tsim ib hom thav duab. Cov hlwb txhawb nqa feem ntau koom nrog hauv kev tswj cov ntshav-thymus barrier.
- Nanka lub hlwb - muaj kev nyuaj siab (invaginations) hauv lawv cov qauv, uas T-lymphocytes tsim.
- Epithelial cells yog cov feem ntau ntawm cov hlwb ntawm thymus cortex.
- Cells ntawm macrophage series yog cov macrophages ib txwm muaj kev ua haujlwm ntawm phagocytosis. Lawv kuj yog cov koom nrog hauv ntshav-thymus barrier.
Kev txhim kho ntawm T-lymphocytes ntawm kev npaj histological
Yogsaib ntawm qhov kev npaj los ntawm lub periphery, ces ntawm no koj tuaj yeem pom T-lymphoblasts uas faib. Lawv nyob ncaj qha hauv qab thymus capsule nws tus kheej. Yog hais tias koj mus los ntawm cov tshuaj ntsiav nyob rau hauv cov kev taw qhia ntawm lub medulla, koj muaj peev xwm pom twb maturing, nrog rau tag nrho cov paub tab T-lymphocytes. Tag nrho txoj kev loj hlob ntawm T-lymphocytes yuav siv sijhawm li 20 hnub. Raws li lawv tsim, lawv tsim T-cell receptor.
Tom qab cov lymphocytes tau loj tuaj, lawv cuam tshuam nrog cov hlwb epithelial. Ntawm no muaj kev xaiv raws li lub hauv paus ntsiab lus: haum lossis tsis haum. Lwm qhov sib txawv ntawm lymphocytes tshwm sim. Qee tus yuav dhau los ua T-tus pab, thaum lwm tus yuav dhau los ua T-killers.
yog dab tsi? Txhua T-lymphocyte cuam tshuam nrog cov antigens sib txawv.
Txog mus rau medulla, twb paub tab T-lymphocytes uas tau dhau los ua qhov sib txawv raug kuaj xyuas raws li txoj cai ntawm kev phom sij. Nws txhais li cas? Qhov no lymphocyte puas tuaj yeem ua mob rau tib neeg lub cev? Yog tias qhov lymphocyte no txaus ntshai, ces apoptosis tshwm sim nrog nws. Ntawd yog, kev puas tsuaj ntawm lymphocyte. Nyob rau hauv lub medulla twb matured los yog maturing T-lymphocytes. Cov T cells no nkag mus rau hauv cov hlab ntsha, qhov chaw uas lawv tawg mus thoob plaws hauv lub cev.
Lub medulla ntawm lub caj pas thymus yog sawv cev los ntawm cov hlwb tiv thaiv, macrophage thiab cov txheej txheem epithelial. Tsis tas li ntawd, muaj cov hlab ntsha lymphatic, cov hlab ntsha thiab Hassall's corpuscles.
Kev txhim kho
Histology ntawm thymus kev loj hlob yog qhov nthuav heev. Ob lub diverticula pib los ntawm 3rd gill arch. Thiab ob qho tib si ntawm cov strands no loj hlob mus rau hauv mediastinum, feem ntau yog cov anterior. Tsis tshua muajlub thymus stroma yog tsim los ntawm ntxiv strands ntawm 4 khub ntawm gill arches. Los ntawm cov ntshav qia hlwb, lymphocytes tsim, uas tom qab ntawd yuav tsiv los ntawm lub siab mus rau cov hlab ntsha, thiab tom qab ntawd mus rau fetal thymus. Cov txheej txheem no tshwm sim thaum ntxov ntawm kev loj hlob ntawm fetal.
Kev tshuaj xyuas ntawm tus qauv histological
Ib luv luv histology ntawm thymus yog raws li nram no: txij li thaum nws yog ib tug classic parenchymal organ, lub chaw soj nstuam pab thawj zaug soj ntsuam cov stroma (organ thav duab), thiab ces lub parenchyma. Kev tshuaj xyuas ntawm qhov kev npaj yog thawj zaug ua tiav ntawm qhov kev nthuav dav siab txhawm rau tshuaj xyuas thiab taw qhia hauv lub cev. Tom qab ntawd lawv hloov mus rau qhov loj ntxiv kom kuaj xyuas cov ntaub so ntswg. Kev npaj yog feem ntau stained nrog hematoxylin-eosin.
Thymus stroma
Sab nraum lub cev yog cov ntaub so ntswg sib txuas. Nws npog lub cev los ntawm txhua sab, muab cov duab. Cov ntaub so ntswg sib txuas kis mus rau hauv lub cev los ntawm cov ntaub so ntswg capsule, lawv kuj hu ua septa, uas faib lub cev mus rau hauv lobules. Nws yog tsim nyog sau cia tias ob qho tib si cov ntaub so ntswg capsule thiab cov ntaub so ntswg sib txuas septa muaj ntom, tsim cov ntaub so ntswg.
Cov ntshav nkag los yog tawm ntawm cov ntshav mus rau hauv lub cev yog nqa los ntawm cov hlab ntsha. Cov hlab ntsha no kuj dhau los ntawm cov ntsiab lus ntawm stroma. Distinguishing cov hlab ntsha los ntawm ib txoj hlab ntsha yog yooj yim heev. Ua ntej, txoj kev yooj yim tshaj plaws yog ua nws raws li qhov tuab ntawm cov leeg nqaij. Cov hlab ntsha muaj ib txheej tuab ntawm cov leeg nqaij ntau dua li cov leeg. Qhov thib ob, choroid ntawm cov hlab ntsha yog thinner dua li ntawm cov hlab ntsha. Hauv qab no hauv daim duab, histology ntawm thymus tuaj yeem pom ntawm kev npaj.
Txhawm rau pom cov ntsiab lus ntawm stroma hauv lub lobule, koj yuav tsum hloov mus rau qhov loj loj. Yog li tus kws pab kuaj pom tau pom cov kab mob reticular epitheliocytes. Los ntawm lawv cov xwm txheej, cov hlwb no yog epithelial, muaj cov txheej txheem sib txuas lus. Yog li, cov hlwb tuav lub thymus thav duab los ntawm sab hauv, raws li lawv tau nruj nreem txuas nrog cov ntsiab lus ntawm parenchyma.
Tus kws pab kuaj mob feem ntau tsis pom cov hlwb ntawm cov ntaub so ntswg reticuloepithelial lawv tus kheej, vim lawv tau muab zais los ntawm ntau txheej ntawm parenchyma. Thymocytes yog nruj heev nyob ib sab mus rau ib leeg uas lawv overlap lub hlwb ntawm lub stroma. Tab sis nyob rau hauv ib qho kev txiav txim, ib tug tseem tuaj yeem pom oxyphilic-stained hlwb ntawm thymocytes hauv lub teeb ci. Cov hlwb no muaj cov nuclei loj uas tau teeb tsa hauv kev chaotic.
Thymus parenchyma
Thymus parenchyma yuav tsum tau txiav txim siab hauv ib daim. Yog li ntawd, tom qab kuaj xyuas cov stroma, tus kws pab kuaj mob rov qab mus rau qhov nce me me. Thaum tus pab kuaj rov qab mus rau nws txoj haujlwm qub, nws pom qhov sib txawv. Qhov sib txawv no qhia tau hais tias txhua lub lobule yog tsim los ntawm cortex thiab medulla.
Cortex
Nws tsim nyog sau cia tias thymus parenchyma yog sawv cev los ntawm lymphocytes. Nyob rau hauv lub cortex, uas stains liab doog ntawm kev npaj (basophilic stain), lymphocytes nyob ze spaced txheeb ze rau ib leeg. Ntxiv nrog rau cov ntsiab lus ntawm stroma thiab lymphocytes, tus kws kuaj mob yuav tsis pom lwm yam hauv cov tshuaj cortical.
Marrow
Oxyphilic xim prevails hauv medulla, thiabtsis basophilic li hauv cortical. Qhov no tau piav qhia los ntawm qhov tseeb tias cov lymphocytes txo qis, thiab lawv tsis tshua muaj nyob sib txheeb. Ntawm cov lymphocytes hauv medulla, thymic lub cev tuaj yeem pom. Cov qauv no feem ntau raug xa mus rau hauv phau ntawv kawm ua Hassall lub cev.
Hassal's corpuscles ntawm kev npaj yog tsim los ntawm cov qauv sib tw. Qhov tseeb, cov no yog cov tuag zoo tib yam, keratinizing fragments ntawm stroma - tib epithelioreticulocytes. Gassall's corpuscles yog oxyphilic-stained ntsiab ntawm thymus medulla.
Ntau zaus, cov tub ntxhais kawm sib txawv thymus npaj hauv histology los ntawm Hassal lub cev. Lawv yog cov yam ntxwv tshwj xeeb ntawm cov tshuaj, ib txwm nyob tshwj xeeb hauv medulla. Daim duab hauv qab no qhia txog cov thymus lub cev.
Yog tias tsis muaj cov qauv liab swirling hauv lub cev, Hassall lub cev zoo li cov pob dawb. Qee lub sij hawm lawv tau muab piv rau qhov tsis muaj (cov khoom cuav) ntawm cov tshuaj, uas feem ntau tsim thaum nws npaj. Ntxiv nrog rau lawv qhov zoo ib yam li cov khoom qub, thymic lub cev zoo ib yam li cov hlab ntsha. Nyob rau hauv rooj plaub no, tus kws pab kuaj xyuas qhov muaj cov leeg nqaij thiab muaj cov qe ntshav liab (yog tias tom kawg tsis tuaj, ces qhov no yog lub cev thymus).
Thymus involution
Raws li tau hais thaum pib ntawm tsab xov xwm, thymus yog menyuam yaus lub caj pas. Tau kawg, qhov no tsis muaj tseeb, tab sis qhov muaj lub cev tsis yog ib txwm txhais tau tias nws ua haujlwm.
Thaum tus menyuam muaj hnub nyoog ib xyoos, lub sijhawm no los txog qhov kev tsim cov lymphocytes, raws li, thiab kev ua haujlwm ntawm lub qog. Tom qab maj mam thymushloov los ntawm cov ntaub so ntswg adipose. Thaum muaj hnub nyoog nees nkaum xyoo, ib nrab ntawm cov thymus muaj cov ntaub so ntswg adipose thiab lymphoid. Thiab thaum muaj hnub nyoog tsib caug, yuav luag tag nrho lub cev yog sawv cev los ntawm cov ntaub so ntswg adipose. Qhov kev cuam tshuam no yog vim qhov tseeb tias T-lymphocytes muaj lub cim xeeb tas mus li uas nrog tib neeg lub cev thoob plaws hauv nws lub neej. Raws li muaj cov T-lymphocytes txaus nyob rau hauv cov ntshav, thymus tsuas yog nyob hauv lub cev uas "tso tseg" qhov tsis tu ncua ntawm T-lymphocytes hauv cov ntshav.
Thymus histology involution tuaj yeem tshwm sim sai dua vim yog cov dej nag. Cov yam ntxwv no tuaj yeem ua rau mob kis kab mob, kab mob ntev, hluav taws xob, thiab lwm yam. Vim yog cov xwm txheej no, qib ntawm cortisone thiab cov tshuaj hormones ntawm qhov xwm txheej steroid nce hauv cov ntshav, lawv rhuav tshem T-lymphocytes tsis paub, yog li rhuav tshem cov thymocytes lawv tus kheej, hloov lawv nrog cov ntaub so ntswg adipose.
