I-thymus ibe yinkinga engavamile kulo lonke umlando. Kwaziwa ukuthi ikhona ngaphambi kwekhulu lokuqala AD, kodwa indima yawo ayingaqala ukuqondakala kuze kube yilapho ezayo. AmaGreki asendulo ayecabanga ukuthi "kwakuyisihlalo sobubindi." Ngesikhathi sokuzalwa kabusha, banquma ukuthi kwakungekho msebenzi. Kwakungakaze kube yi-1970 ukuthi indima yawo emasosheni omzimba aqala ukuvela.
Thymus Basics
Namuhla siyazi i-thymus njengegciwane lesistimu yomzimba. Ngaphansi kwesimiso somzimba sokuvikela omzimba, amaseli egazi amhlophe ahlukile anemisebenzi ehlukile. Ama-lymphocytes, noma ama- T-amangqamuzana , uhlobo olulodwa lweseli elimhlophe legazi. Kubantu, i-thymus iyisitho ongacabanga ngaso ngokuthi 'ikampu yeboot' yezingane T-lymphocytes. Yindawo yokukhula, ukuthuthukiswa, ukuqeqeshwa nokukhethwa kwama-T-lymphocytes, amasosha omzimba omhlophe-wegazi, ukuze bakwazi ukuvuthwa ukuba baphume futhi balwe nezifo kanye nabahlaseli bangaphandle.
I-'T 'kuma-T-cell empeleni imelela i-thymus, kuyilapho i-' B 'kuma- B-cell ebhekisela emnothweni wethambo. Wonke amangqamuzana akho amhlophe egazi akwenziwa emnothweni wethambo; kuphela i-subset ekhethekile yalezi zinqamuzana ezenza igazi ezihamba ukusuka emnothweni we-bone kuya ku-thymus, lapho ziqeqesha khona ukuba zibe yi-T-lymphocytes.
Ngesinye isikhathi, abantu akuzona kuphela izidalwa eziba ne-thymus-empeleni, i-thymi yamathole futhi ngezinye izikhathi iwundlu liphakathi kwezitho ezilungiselelwe esitsheni esibizwa ngokuthi ama-sweetbreads, okwakudumile eBrithani.
Indawo kanye nobukhulu be-Thymus
I-thymus ingumgogodla endaweni ephezulu yesifuba / phansi entanyeni. I-thymus ijwayele ukudideka ne-thyroid-igwebu elisendaweni efanayo, kepha inomsebenzi ohluke kakhulu. I-thymus iyi-gland epholile, ephuzi elibomvu elitholakala ngemuva kwesifuba sakho kanye naphakathi kwamaphaphu akho.
Odokotela bayibiza le ndawo yesifuba njengo- mediastinum , futhi kugobhozele izakhiwo ezibalulekile.
Kubantu, i-thymus ayiyona into ebonakalayo noma ebonakalayo ngaphandle. Okusho ukuthi isithunzi esivela ku-thymus ngezinye izikhathi singabonakala ku-x-ray; Kodwa-ke, izibani noma ama-bulges esifundeni sezintamo kungenzeka kakhulu ngenxa yezinye izinto, ezifana nezindwangu zamagciwane ezivuvukala noma ama-cysts. Ngokuvamile, ingxenye ye-thymus iyaqhubeka entanyeni kunalokho okumele ibe-okuthiwa i-ectopic cervical thymus.
Ngokuya ngobudala bakho, kunamathuba ukuthi unayo okungenani izinsalela ze-thymus, kodwa ezimweni eziningi, abantu abadala abanalo i-thymus esebenzayo. Ngemuva kokukhulelwa, i-thymus iqala ukunciphisa kancane, noma i-atrophy, futhi ithathe indawo esikhundleni samafutha. Nokho, ungakhathazeki, ngoba kuvunywa ukuthi i-thymus iveza wonke ama-T-cells oyoke uwadinge ngaphambi kwalokhu. Nakuba imisebenzi ye-thymus ibonakala igaya ukuma lapho umuntu ekhulile ngaphandle kokungavamile, ama-T-lymphocytes aqhubeka akhiqizwa emzimbeni wakho futhi agcwaliswa phakathi nokuphila kwakho konke.
Abantu bangahluka kakhulu ngobukhulu nokuma kwe-thymus yabo. I-thymus ikhulu kakhulu uma singabantwana, sinesisindo esingama-25 amagremu lapho sizalwa.
Ukufinyelela isisindo esiphakeme phakathi kweminyaka engu-12 no-19, cishe amagremu angu-35 ngokwesilinganiso, i-thymus kancane kancane iyanciphisa iminyaka engaphezu kwengu-20 kuya kweyengu-60, ngokufaka esikhundleni sesisindo se-thymus ngamathishu amafutha. Isilinganiso cishe cishe amagremu angu-15 ngesikhathi uneminyaka engu-60 ubudala.
The Thmus Is 'Umeluleki Umsebenzi' for Baby White Amaseli Egazi
Amangqamuzana egazi-omabili amangqamuzana abomvu namhlophe-avela kuma-stem cells ahlala kuwo noma avela emnothweni wethambo. Ngesikhathi intuthuko yengane, amaseli esandulela emangeni asuka emthonjeni we-thymus, lapho amangqamuzana e-thymus enikeza khona indawo efanelekile, ne-cell receptors nama-chemical signals, ukuze azivuselele kahle.
Lapho ama-progenitors e-T esuka emnothweni we-thymus, abizwa ngokuthi i-thymocytes, futhi izimpawu namahomoni avela ku-thymus, kufaka phakathi i-thymopoietin ne-thymosin, iqondisa ukuthuthukiswa kwe-thymocytes ibe ngama-T-cell omdala.
I-thymus yenza isiqiniseko ukuthi lezi thymocytes zikhula zibe ne 'imishini' noma izimpawu zangaphandle ngaphandle kweseli. Kukhona nenqubo yokukhethwa nokukhipha. Ngokwesibonelo, kwelinye lama-checkpoints amaningana, amaphesenti angaba ngu-95 we-thymocyte aphuma enokhula-kuphela amaphesenti amathathu kuya kwangu-5 we-thymocytes asinda. Abasindile bahlukanisa ngezici ezikhethekile (CD8 + noma CD4 +) i-lymphocytes futhi bachitha cishe izinsuku ezingu-10 endaweni ethile ye-thymus, lapho bafunda ukutshela umehluko phakathi kwamakaki 'ngabanye' nabamemezeli bangaphandle. Emva kwalolu hlelo oluyinkimbinkimbi, ama-T-amaseli angashiya i-thymus futhi enze imisebenzi yawo ehlukahlukene esimisweni somzimba sokuzivikela.
Izinkinga eziyingozi
Ukwandiswa kungenziwa ekuphenduleni okuthile, noma kungaba umphumela wenqubo yesifo. Ngezinye izikhathi ngesikhathi sokucindezeleka noma emva kokwelashwa ngemithi ethile efana ne-chemotherapy ne-steroids, i-thymus ingase ikhulise. I-thymus ingabuye yandiswa ngendlela eyaziwa ngokuthi i-lymphoid hyperplasia, noma i-thymithis ehamba nge-autoimmune, engase ihlotshwe nezifo ezifana ne- myasthenia gravis , i-systemic lupus erythematosus, i-rheumatoid arthritis, i-scleroderma, ne-Graves isifo. Ezinye zalezi zinkinga zingase zihlotshaniswe ne- lymph nodes .
Uma odokotela behlola i-thymus yakho ekucabangeni, bazama ukuhlukanisa ukuthi ngabe iphethini yileyondlela yokukhulisa i-thymus ngokuhambisana neyokulimala, okuvame ukuqala ngaphezulu njengezindawo ezigxile ekukhuleni noma ekukhuliseni izixuku. Ngokuvamile, izicubu ze-thymus azivamile. Kulinganiselwa ukuthi cishe amacala angu-1.5 kuphela akhona kubantu abayizigidi ngonyaka ngamunye e-US, noma ngamacala angu-400 ngonyaka.
I-Thymoma ngokumelene ne-Carcinoma ye-Thymic: I-thymoma yisisu lapho amangqamuzana e-tumor abukeka afana namaseli avamile we-thymus. I-thymomas ikhula kancane futhi ingavamile ukusabalalisa ngaphandle kwe-thymus. Ngokuphambene, amangqamuzana e-tumor e-carcinoma ye-thymic abukeka ehluke kakhulu kumaseli we-thymic enempilo, anokukhula okusheshayo, futhi avame ukusabalalisa kwezinye izindawo lapho umdlavuza utholakala. I-carcinoma ye-thymic kunzima ukwelapha kune-thymoma.
I-Myasthenia Gravis: I- Myasthenia gravis yisifo esizimele esihambisana nesifo sobuthakathaka emisipha yomzimba. Cishe amaphesenti angu-30 kuya ku-65 abantu abanamakhomomas bane-myasthenia gravis, futhi lokhu sekude futhi sekude nesifo esivame kakhulu esizimele ezihambisana ne-thymomas. E-myasthenia gravis, umzimba ngokungalungile wenza ama-antibodies abe nama-receptors esakhiweni se-cell muscle, evimbela izibonakaliso zamakhemikhali ezibangela ukuba imisipha ihambe, okuholela ekubuthakathakeni okukhulu kwesisu.
Abantu abane-myasthenia gravis bangakwazi ukukhathala kalula futhi bangabona ubunzima lapho bekhuphuka izitebhisi noma behamba amabanga amade. Abantu abaningi abane-thymomas bane-myasthenia gravis, kodwa abantu abaningi abane-myasthenia gravis abanayo i-thymomas.
Ukuthuthukiswa okuncane noma okungajwayelekile: Izimo ezivimbela ukuthuthukiswa okuvamile kwe-thymus zingathinta isimiso somzimba sokuzivikela. I-DiGeorge syndrome yisinye isimo esinjalo esihlotshaniswa noshintsho lwezakhi zofuzo, kaningi ukususwa kolwazi lofuzo oluvela ku-chromosome ethile, i-chromosome 22. Zonke izinhlobo ezahlukene ze-thymic ezingavamile zingenzeka ku-DiGeorge syndrome, noma kunjalo. Nokho, iningi labantu abane-syndrome, linomsebenzi okwanele wokusebenzisa amathambo we-thymic ukuthuthukiswa kwamaseli a-T enempilo. Ukungabi khona kwe-thymus kungapheli, kodwa kubonakala kungavamile kwiziguli ezine-DiGeorge syndrome.
> Imithombo:
> The Thymus Gland: Ukuxilongwa Nokuphathwa Okuhlinzekwa yi-Kyriakos Anastasiadis, uCandi Ratnatunga. I-Springer Science & Business Media, Juni 7, 2007.
> Baron RL, Lee JK, uSagel SS et-al. I-tomography ehlanganisiwe ye-thymus evamile. I-Radiology. 1982; 142 (1): 121-5.
> Popoveniuc G, Sharma M, Devdhar M et-al. Isifo se-Graves ne-hyperplasia ye-thym: ubuhlobo bomthamo we-thymic kuya emsebenzini we -roid. I-Thyroid. 2010; 20 (9): 1015-8.