Te Hua o te Au o te Ate
Ko te ate tētahi o ngā okana tino pukumahi o te tinana tangata. Haunga tana mahi ki te tango i ngā paitini, ki te penapena pūngao, me te whakahaere i te pākia o te tinana, he mahi nui anō hoki tā te ate, e warewarehia ana: te whakaputa au. He wai nakunaku te au e tika ana mō te āwhina i te tinana ki te nakunaku i ngā ngako me te mimiti i ētahi huaora. Ehara i te mea ngāwari te tukanga hanga au ; he maha ngā tikanga koiora uaua e uru ana, mai i te taumata pūtau ki te pūnaha awa au. Ka matapakihia e tēnei tuhinga te āhua o te whakaputa au e te ate, ōna wāhanga, te āhua o tana haere ki ngā whekau, me te take he mea nui tēnei tukanga mō te hauora.
He aha te waikura, ā, he aha i hiranga ai?
He wai kakariki-kōwhai te au o te ate e whakaputaina tonutia ana . Ko tana mahi matua he whakapūmau i ngā ngako—te wawahi i ngā ngako kia iti—kia pai ake ai te mahi a ngā whākōkī nakunaku (lipases). Ki te kore he au, kāore e tino pai te nakunaku o ngā ngako, ā, ka uaua ki te tinana te mimiti i ngā waikawa ngako me ngā huaora wairewa-ngako pērā i ngā huaora A, D, E, me te K.
Haunga te āwhina i te nakunaku, ka mahi anō te au hei ara mō te whakakore i ētahi hua para. Hei tauira, ka taea te whakaputa i te bilirubin (he hua pakaru o te hemoglobin), te cholesterol nui, me ētahi hua pākia me ngā rongoā mā te au. Nō reira, ehara i te mea ko te nakunaku anake te take o te au engari ko te "ma" o te tinana.
Ngā wāhanga matua o te au
Ehara te wai au i te "wai nakunaku" anake, engari he ranunga matatini kei roto:
1. Ngā tote au: i ahu mai i ngā waikawa au i hangaia mai i te cholesterol. He wāhanga matua ēnei i roto i te whakaemulsification ngako.
2. Ngā phospholipid (ina koa ko te lecithin): ka āwhina i te hanga micelles me ngā tote au, ka āwhina i te mimiti ngako.
3. Korekore: Ka tukuna ētahi o ngā korekore ki roto i te au. Mēnā he nui rawa, ka taea te hanga i ngā kōhatu au.
4. Bilirubin: he tae e puta mai ana i te pakaru o ngā toto whero, e homai ana te tae ki te au.
5. Ngā irahiko me te wai: ka nui ake te wai o te au o te ate kia ngāwari ai te rere mā roto i te awa au o te ate.
6. Ngā pūmua me ētahi atu matū: tae atu ki ētahi para pākia me ngā matū e tika ana kia tukuna.
Ka rerekē te hanganga o te au i runga i te āhua o te tinana, te kai, me te whakahohenga o ngā homoni nakunaku.
Ko wai te "hanga" i te au i roto i te ate?
Ka hangaia te aukume e ngā pūtau ate e kiia nei ko ngā hepatocytes. Ko ngā hepatocytes te nuinga o ngā kiko ate, ā, ka rite ki ngā wheketere matū koiora te mahi. Ka tangohia e rātou ngā rauemi mata mai i te toto, ka tukatukahia, kātahi ka hangaia te aukume, ka haria mā roto i ngā awa iti i roto i te ate.
Haunga ngā hepatocytes, kei roto anō hoki i ngā awaawa aukume ngā pūtau epithelial e kiia nei ko ngā cholangiocytes. Kāore ngā cholangiocytes e hanga aukume mai i te tīmatanga pērā i ngā hepatocytes, engari ka "whakarerekē" rātou i te aukume—hei tauira, te tāpiri wai me te paikāponate—kia taea ai te whakarerekē i te rahinga me ngā āhuatanga o te aukume kia tutuki ai ngā hiahia nakunaku.
Ngā wāhanga o te whakaputa waikura i te ate
1. Te hanganga waikawa te ate mai i te cholesterol
Ko te mahi nui o te whakaputanga o te aukume ko te whakaputanga o ngā waikawa aukume. Ka hangaia ngā waikawa aukume mai i te cholesterol mā roto i tētahi raupapa o ngā tauhohenga whākōkī i roto i ngā pūtau ate. Ko tētahi whākōkī matua i roto i tēnei ara ko te cholesterol 7α-hydroxylase (CYP7A1), e whakahaere ana i te nui o te waikawa aukume e whakaputaina ana.
Kātahi ka taea te hono (whakakotahi) i ngā waikawa au hou kua hangaia ki ngā waikawa amino pēnei i te glycine, te taurine rānei. Mā tēnei tukanga hono ka wairewa ake ngā waikawa au i te wai, ā, ka whai hua ake hoki ki te āwhina i te nakunaku ngako. I muri i te honotanga, ka kiia ngā waikawa au e puta mai ana ko ngā tote au.
2. Te hunanga o ngā wāhanga o te au ki roto i ngā awaawa au
Kia oti ngā wāhanga o te au o te ate te hanga, ka tukuna e ngā pūtau ate ki roto i ngā awaawa moroiti e kiia nei ko ngā awaawa o te au o te ate. He "awaawa" ririki ēnei awaawa kei waenganui i ngā pūtau ate. Koinei te wāhi ka tīmata te rere o te au o te ate.
Ko te rere o te aukume me mahi i ngā momo kaikawe (ngā pūmua whakawhiti) ki runga i te kiriuhi pūtau ate. Ka pupuhihia ngā tote aukume, te bilirubin honohono, ngā phospholipid, me ētahi atu matū ki roto i ngā canaliculi. Mā te nekehanga o ēnei matū ka kukume i te wai me ngā electrolytes mā te osmotic, ka whakanui ake i te rahinga o te aukume, ā, ka whakamāeneene kia tika ai te rere.
3. Te whakarerekētanga o te au o te ate e ngā pūtau awa au
Ko te au i hangaia tuatahitia e ngā hepatocytes ka kiia ko te au tuatahi. I a ia e haere ana i roto i ngā awa au i roto i te ate (ngā awa au i roto i te ate), ka taea e ngā cholangiocytes te tāpiri i te paikāponate (HCO₃⁻) me te wai. Mā te tāpiri i te paikāponate ka āwhina i te whakakore i te waikawa o te puku i te mea ka uru ngā ihirangi o te puku ki te whekau iti, ka pai ake te taiao whekau mō te mahi a te whākōkī nakunaku.
Ka pāngia tēnei whakahaere e ngā homoni pēnei i te secretin, e whakaoho ana i ngā awaawa o te ate ki te whakaputa wai whai kiko i te paikāponate.
4. Te rokiroki me te kukū i roto i te pūkahukahu
Ahakoa ka puta tonu te au o te ate, kāore e rere tika tonu ki roto i ngā whekau. Ina kore he kai, inā koa ngā kai momona, ka whakawhitia te au o te ate ki te au o te puku hei penapena. I roto i te puku o te puku, ka kukū te au o te ate: ka mimitihia anō te wai me ētahi electrolytes, ka matotoru ake te au o te ate, ka kaha ake ina hiahiatia.
5. Te tukunga o te au ki roto i te whekau iti i te wā e kai ana
Ina kai koe, inā koa ngā kai kei roto te ngako, ka tukuna e tō whekau iti te homoni cholecystokinin (CCK). Mā tēnei homoni ka whakawhāiti te pūkahukahu me te tuku i te au ki roto i te awa au matua, kātahi ka uru ki te duodenum (te wāhanga tuatahi o te whekau iti). I taua wā anō, ka āwhina hoki te CCK ki te whakangāwari i te sphincter o Oddi, te "valve" e whakahaere ana i te rere o te au me ngā wai pancreatic ki roto i te whekau.
I muri i te urunga o te au ki te whekau iti, ka mahi ngā tote au i tā rātou mahi: te hanga i ngā micelles, te here i ngā ngako me ngā huaora wairewa-ngako, kātahi ka kawe i ngā hua nakunaku ki te mata o te whekau kia mimitia.
Te huringa enterohepatic: ka "whakamahi anō" te au
He mea whakamīharo, kāore te tinana e tuku i ngā tote au katoa i muri i te whakamahinga. Ko te nuinga o ēnei ka mimitihia anō ki te wāhanga whakamutunga o te whekau iti (ileum) ka haria anō ki te ate mā te uaua portal. Ka kiia tēnei tukanga ko te tohanga enterohepatic.
He tino whai hua tēnei huringa. Ka taea te whakamahi anō i ngā tote au i ngā wā maha i te rā. He iti noa ngā waikawa au hou e hiahiatia ana e te ate hei whakakapi i ngā mea i ngaro i roto i ngā paru. Mā tēnei pūnaha hangarua ka āwhina te tinana ki te penapena pūngao, ā, ka pupuri i ngā tote au e wātea ana mō te nakunaku.
Ka aha mēnā ka whakararuraruhia te hanga, te rere rānei o te au?
Ka pā mai ngā raruraru hauora maha i ngā raruraru o te whakaputanga, o te rere rānei o te au, hei tauira:
– Cholestasis (ārai i te rere o te aukume): ka hua ake te nui o te bilirubin me ngā tote aukume i roto i te toto, ka puta ai te kiri mākūkū, te mimi pouri, te tūtae koma, me te jaundice.
– Ngā kōhatu o te pūhā: ka puta pinepine mai ina nui rawa te cholesterol i roto i te au, ina kore rānei e taurite te hanganga o te au.
– Te ngoikore o te mimiti ngako: ka puta te paru hinuhinu (steatorrhea) me te korenga o ngā huaora A, D, E, K i roto i te korenga o te au.
– Te kino o te ate, te awa wai rānei: pērā i te mate hepatitis, te cirrhosis, te mumura rānei o ngā awa wai ka pā ki te whakaputa/te kawe i te wai.
Nā te mea he wāhi te au o te ate ki te nakunaku me te tango i ngā para, he maha ngā pānga o ngā mate o te pūnaha au, ehara i te mea ki te puku anake engari ki te āhua o te kiri, te pūngao, me te pākia o te kai.
Te Katinga
He tukanga tino taunga te whakaputanga o te aukume e te ate. Ka hangaia e ngā hepatocytes ngā waikawa aukume mai i te cholesterol, ka tukuna ngā tote aukume me ētahi atu wāhanga ki roto i ngā awa aukume, kātahi ka whakarerekē i te aukume i te taha o ngā awa aukume i mua i te penapena me te whakawhāiti i roto i te pūkahukahu. Ina kainga ngā kai ngako, ka tukuna te aukume ki roto i te whekau iti hei āwhina i te nakunaku ngako me te mimiti huaora. I muri i te whakamahinga, ka hangarua te nuinga o ngā tote aukume mā te tohanga enterohepatic.
Mā te mārama ki te āhua o te whakaputanga o te au o te ate ka kitea ai ehara tēnei okana i te "tātari paitini" noa iho, engari he kaiwhakahaere nui o te pākia o te tinana me te nakunaku. Ko te pupuri i te hauora o te ate mā te kai taurite, te korikori tinana, me te tirotiro hauora ina pāngia ana e ngā raruraru nakunaku, ngā tohumate rānei o te jaundice he mahi nui hei whakarite i te mahi pai o te au o te ate.
