Gulu la chithokomiro ndi chiwalo chooneka ngati gulugufe, pafupifupi masentimita awiri m'lifupi ndi masekeli 10 mpaka 20, pamunsi mwa khosi kutsogolo kwa trachea (windpipe). Ntchito yake ndi kupanga mahomoni omwe ali ofunikira kwambiri kuti thupi likhazikike komanso ntchito zina zofunika kwambiri.
Mahomoni awiri akuluakulu otuluka ndi chithokomiro-thyroxine (T4) ndi triiodothyronine (T3) -help kuti alamulire, mwa zina, mtima wa kulemera, kulemera kwa thupi, mphamvu ya minofu, kupuma, kutentha kwa thupi, kupha magazi, kusamba, dongosolo la manjenje, ndi kugwiritsa ntchito mphamvu zamagetsi.
Kwa makanda, mahomoni a chithokomiro ndi ofunikira kuti ubongo ndi chitukuko chikule bwino. Choncho, chithokomiro chogwira ntchito nthawi zambiri chimakhala chofunikira kwambiri kuti mwana akule bwino, komanso kwa moyo wabwino wautali ndi mphindi imodzi.
Chimene Chithokomiro Chimachita
Ndi ntchito ya chithokomiro kuti mukhale ndi mahomoni a chithokomiro, T3 ndi T4. Chizindikiro cha mahomoni a chithokomiro ndi chakuti ali ndi ma atomu a ayodini-T3 ali ndi ma atomu atatu a ayodini, ndipo T4 ali ndi zinayi. Motero, chithokomiro n'chosiyana kwambiri ndi mphamvu yake yapadera yotenga ayodini kuchokera m'magazi, kuti aikidwe mu mahomoni a chithokomiro.
T4 onse m'thupi amapangidwa ndi chithokomiro-pafupifupi 80 mpaka 100 mcg pa tsiku. Nthawi pafupifupi 10 kuchuluka kwa T4 (pafupifupi 1000 mcg) kumazungulira m'magazi. Pafupifupi 99 peresenti ya T4 yoyendayenda imakhala ndi mapuloteni m'madzi a plasma (makamaka, ku matenda a chithokomiro omwe amamanga thupi, TBG).
Ndikochepa kokha kozungulira T4 kosawerengeka ("kofiira" T4) komwe kulipo kuti kagwiritsidwe ntchito.
Pafupifupi 10 peresenti ya T4 yozungulira (yofanana ndi kuchuluka kwa T4 yatsopano yotulutsidwa tsiku ndi tsiku ndi chithokomiro) imanyozedwa tsiku lililonse. Kawirikawiri, pafupi theka la ndalamayi amatembenuzidwa kukhala T3 (mwa kukakamira mbali imodzi ya maatomu a iodini), ndipo otsalirawo amasandulika kuti "abwererenso T3 " (rT3, pochotsa atomu ya ayodini kuchokera kumalo ena).
T3 ndi mankhwala otentha a chithokomiro, pamene rT3 sichigwira ntchito.
Pafupifupi 20 peresenti ya T3 m'thupi imatulutsa khungu la chithokomiro. Ma 80% amapangidwa kuchokera ku T4 mkati mwa matenda-makamaka impso, chiwindi, minofu, ubongo, khungu, ndi placenta. Zomwe timapanga T3 patsiku ndi pafupifupi 30-40 mcg, ndipo zambiri mwa T3 kunja kwa chithokomiro zili mkati mwa maselo a thupi. T3 imanyozedwa mofulumira kwambiri kuposa T4.
Njira yothandiza kuyang'ana mahomoni a chithokomiro ndikutenga T4 kukhala "pro-hormone" ya T3-ndiko kuganiza za T4 monga chida chachikulu cha "chokhoza" T3. Mtengo woyenera wa T4 watembenuzidwa pa nthawi yoyenera ku T3, malinga ndi zosowa za thupi ndi miniti. T3 ndiye ntchitoyo. Pofuna kupewa kuthamanga kwambiri kwa T4, "T4" yambiri imasinthidwa kukhala rT3, yomwe imagwiritsidwa ntchito ndi zida.
Zimene ma Hormoni amachititsadi
Momwemonso, mahomoni a chithokomiro-makamaka, T3-amatsogolera mwachindunji kupanga mapuloteni osiyanasiyana opangidwa ndi maselo a thupi. T3 imachita zimenezi pogwiritsa ntchito DNA ya selo.
Free T4 ndi T3 yomwe imafalitsidwa m'magazi imapezeka kuti nthawi yomweyo alowe mumaselo a thupi nthawi zonse.
Zina mwa t4 tambirimbiri timatembenuzidwa kukhala T3, ndipo zina mwa T3 zimamanga ku T3-receptors mwachindunji cha selo. Izi zimagwirizanitsa T3 zimayambitsa nyukiliya ya DNA kuyambitsa (kapena kulepheretsa) kupanga mapuloteni enieni.
Maselo osiyanasiyana m'thupi ali ndi mitundu yosiyanasiyana ya T3-nyukiliya receptors, ndipo mosiyana, kotero zotsatira za T3 mu selo zimasiyana kwambiri kuchokera minofu mpaka minofu, ndi pansi pa zochitika zosiyanasiyana. Komabe, m'madera onse mahomoni a chithokomiro amagwira ntchito poyang'anira ntchito ya DNA, zomwe zimapangitsa kuti pang'onopang'ono kapena kuchepetsa kupanga mapuloteni ovuta kwambiri.
Pakati pa mapuloteni amenewa pali mavitamini osiyanasiyana omwe amawongolera khalidwe la ntchito zambiri za thupi.
Momwe Kachitidwe ka Chithokomiro Chimalembedwera
Monga taonera, mahomoni a chithokomiro ndi ofunikira pa nthawi zonse komanso nthawi ndi mphindi zoyang'anira ntchito zambiri za thupi. Nthawi iliyonse thupi lathuli ndi lovuta kwambiri, tidzatha kuona kuti chilengedwe chimapanga malamulo osiyanasiyana, pofuna kutsimikiza kuti dongosololi likukonzekera bwino kuti lichite zomwe likuyenera kuchita, komanso kuti ntchito yake ikuyendetsedwa bwino. Zigawo zowonjezereka zapamwambazi zimagwira ntchito pa chithokomiro.
Tiyeni tiwone mwachidule "zigawo" zazikulu za malamulo a chithokomiro.
Nthenda ya Chithokomiro. Nthenda ya chithokomiro imapereka mphamvu yoyang'anira chithokomiro chokha. Gland ya chifuwa (gland yomwe ili mkatikati mwa ubongo) imatulutsa TSH, kapena kutentha kwa majeremusi. TSH imachititsa kuti chithokomiro chiwonjezere kupanga ndi kutulutsa T3 ndi T4. Pa nthawi imodzimodziyo, kutulutsa mahomoni a chithokomiro (makamaka T3) amaletsa TSH kupanga ndi pituitary, motero amapanga chithunzi cholakwika. Choncho, monga momwe magazi a T3 akuchulukira, magulu a TSH akugwa. Kutsekemera kotereku kumapangitsa kuti mahomoni a chithokomiro apangidwe ndi khungu la chithokomiro mkati mwazing'ono zochepa.
The Hypothalamus-Pituitary Axis. Kutulutsidwa kwa TSH ndi chithokomiro cha pituitary, kuphatikizapo kuyankha pozungulira T3, kumathandizidwanso ndi kutulutsa TRH (thyrotropin-release hormone) ndi hypothalamus. Kutulutsidwa kwa TRH ndi hypothalamus kumapangitsa kuti pituitary gland kumasulire zambiri TSH, motero, kumawonjezera kuchuluka kwa hormone kupanga ndi chithokomiro gland.
The hypothalamus ndi gawo loyamba la ubongo lomwe limagwirizanitsa ntchito zambiri za thupi, monga circadian nyimbo, neuroendocrine dongosolo, dongosolo lodzidzimitsa mantha, ndi ena ambiri. The hypothalamus imayankha zovuta zambiri kuphatikizapo kuwala ndi mdima, kununkhira, kutulutsa mawu, mahomoni angapo, kupsinjika maganizo, ndi maonekedwe a neural kuchokera mu mtima ndi matumbo.
Choncho kutulutsa ma hormoni sizitengera kotheratu ku TSH, koma zimadaliranso zomwe hypothalamus ndi "kuganiza ndi kumverera" za chikhalidwe chonse cha thupi ndi chilengedwe.
Mapuloteni Akuphimbidwa ndi mavitamini a chithokomiro. Monga taonera, mahomoni ambiri omwe amapezeka m'magazi amatha kupitirira 99%, makamaka kwa TBG. Komanso, mavitamini otere a m'thupi amaphatikizidwa. Ndiyi T4 ndi T3 omwe ali ndi ntchito iliyonse ya physiologic.
Mapuloteni omwe amamanga mahomoni a chithokomiro amatha kugwira ntchito zovuta kwambiri. Zimapereka nkhokwe yaikulu yozungulira T4 kuti itetezedwe ndi kuchepetsa mwadzidzidzi kuchitidwa kwa chithokomiro, pomwe mukukhalabe ovuta kwambiri T3 ndi T4 mkati mwa malire ochepa kwambiri.
Ngati sitima ya T4yi idawonekere, ziwalozo zikanakhala ndi mahomoni a chithokomiro mkati mwa maola angapo, ngati chithokomiro chikanakhala chosayenera.
Mapuloteni omwe amachititsa mahomoni a chithokomiro amatetezeranso kuwonjezeka kwadzidzidzi komwe kumayendera T3, ngati ziwalozi zikuwonjezereka kutembenuka kwa T4 mpaka T3.
Mapuloteni a ma chithokomiro . Monga taonera, T3 ndi T4 amachita ntchito yawo yofunika mkati mwa maselo. Zomwe zimagwira ntchito mkati mwa maselo-kuphatikizapo zoyendetsa pa memphane kuchokera m'magazi mpaka mkati mwa maselo, kutembenuka kwa T4 mpaka T3, kudutsa kwa T3 m'kati mwa selo, ndikugwirizanitsa T3 mpaka DNA-kumadalira kuchuluka kwa mapuloteni otsogolera ndi oyendetsa mkati mwa maselo omwe maonekedwe ndi zikhalidwe zawo zimapezekabe.
Chidule . Matenda a chithokomiro amalamulidwa pamagulu ambiri. Malamulo akuluakulu amatha kupyolera mwa chithandizo cha chithokomiro chomwe chimaperekedwa ndi hypothalamus kuti chidziwitse kufunikira kwa thupi lonse), chimatengera momwe hormoni ya chithokomiro imatulutsa ndi kutulutsa. MaseĊµera omasuka otulutsa mahomoni omwe amapezeka ku ziphuphu amamenyedwa, pamagulu a miniti ndi miniti, ndi TBG ndi mapuloteni ena omwe amamanga chithokomiro. Ndipo, panthawi imodzimodziyo, kumangidwa kwa T3 mpaka T3-nyukiliya receptors, pa malo a DNA ya selo, kumawoneka kuti ikulamulidwa ndi mapuloteni angapo opangidwa ndi maselo ambiri. Njira imeneyi yotsimikizira kuti mahomoni ambiri amapezeka nthawi zonse mpaka kumatenda, koma nthawi yomweyo amalola kuti chithokomiro cha DNA chikhale mkati mwa maselo.
Kusokonezeka kwa chithokomiro
Ndizo malamulo ambiri, pamagulu ambiri. Ndipo zikutanthawuza kuti matenda a chithokomiro amatha kukhala ndi matenda okhudza chithokomiro chokha, kapena ndi zinthu zomwe zimakhudza hypothalamus, pituitary, kapena mapuloteni a magazi, kapena ngakhale ndi matenda omwe amachititsa kuti mahomoni a chithokomiro azigwira ntchito zosiyanasiyana.
Kawirikawiri, vuto la chithokomiro limayambitsa matenda a chithokomiro kukhala operewera ( hypothyroid ), kapena owonjezera ( hyperthyroid ). Kuwonjezera pa mavutowa, matenda a chithokomiro akhoza kukulitsidwa kwambiri (chikhalidwe chotchedwa goiter ). Khansara ya chithokomiro imayambanso. Zonsezi ndizovuta kwambiri.
Zizindikiro za matenda a chithokomiro zingakhale zosiyana. Zizindikiro za hypothyroidism nthawi zambiri zimakhala ndi khungu louma, kuchepa mtima kwa mtima, ulesi, kudzikuza, kusintha kwa khungu, kutaya tsitsi, kupuma, kulemera, ndi zina zambiri. Zizindikiro zofanana za hyperthyroidism zimaphatikizapo kuthamanga kwa maso, maso owuma, kumva mphamvu, kusowa tulo, kupukuta tsitsi, kufooka, ndi mantha - komabe palinso zizindikiro zina zambiri zomwe zingaoneke. Werengani zambiri za matenda a chithokomiro .
Kuzindikira vuto la chithokomiro kumafuna kufufuza mosamalitsa kusanthula mayesero a magazi a chithokomiro, komanso kuyesedwa kwina ngati chithokomiro chikuwoneka. Werengani za kuyesa kwa chithokomiro .
Pofufuza matenda a chithokomiro, kuyang'ana khungu la chithokomiro ndilofunika kwambiri. Izi zikhoza kuchitidwa poyeza serum yaulere T3 ndi T4, ndi ma samu a TSH a seramu. Ngati miyeso ya TSH ikukwera, imasonyeza kuti chithokomiro sikutulutsa mahomoni okwanira, ndipo pituitary ikuyesera kukwapula ntchito yake. Ngati magulu a TSH amaletsedwa, zikhoza kutanthauza kuti chithokomiro chimatulutsa mahomoni ambiri a chithokomiro.
Nthawi zina, kutanthauzira moyenera mazinga a TSH kungakhale kovuta, ndipo kungakhale kutsutsana. Werengani zambiri za kuyesa ndi kutanthauzira TSH .
Matenda opatsirana a matenda a chithokomiro angakhalenso achinyengo, koma nthawi zambiri vuto limatha kusankha pakati pa mankhwala osiyanasiyana, osati kufunafuna chithandizo chimene chimagwira ntchito konse. Werengani za zina mwa zotsutsana ndi chithandizo cha hypothyroidism , ndi hyperthyroidism .
Mawu Ochokera
Matenda a chithokomiro, ndi mahomoni omwe amapanga, ndi ofunikira kwambiri pa chitukuko cha anthu ndi moyo wathanzi. Kuipa kwa chithokomiro kumagwirizanitsidwa ndi njira zovuta zomwe chilengedwe chakhazikitsira kuti muwononge mahomoni a chithokomiro. Chifukwa chithandizo cha chithokomiro n'chofunika kwambiri, ndikofunika kwambiri kuti tidziwe bwino ndikuthetsa vuto lililonse la chithokomiro.
> Zotsatira:
> Brent GA. Njira za Kutentha kwa Hormone. J Clin Invest 2012; 122: 3035.
> Jonklaas J, Bianco AC, Bauer AJ, et al. Malangizo a Chithandizo cha Hypothyroidism: Wokonzedwa ndi American Thyroid Association Task Force pa Kutentha Hormone m'malo. Chithokomiro 2014; 24: 1670.
Mullur R, Liu YY, Brent GA. Chithokomiro cha Hormone Control of Metabolism. Physiol Rev 2014; 94: 355.
> Ross DS, Burch HB, Cooper DS, et al. 2016 Makomiti a Chithokomiro cha America a ku America Otsogolera Kuzindikira ndi Kusamalira Hyperthyroidism ndi Zina Zimayambitsa Thyrotoxicosis. Chithokomiro 2016; 26: 1343.