Ngā Tauhohenga Matū i roto i te Tukanga Nakunaku
Ko te nakunaku he raupapa o ngā tukanga e huri ana i te kai hei ngota māmā kia taea ai e te tinana te mimiti me te whakamahi hei pūtake pūngao, hei poraka hanga, hei whakahaere hoki i ngā mahi ā-tinana. Kei muri i ngā tukanga "mīhini" pēnei i te ngaungau me te huri i te kai i roto i te puku, he tino uaua ngā tauhohenga matū. Kei roto i ēnei tauhohenga ngā whākōkī, ngā waikawa, ngā kawa, me ngā momo matū koiora e mahi ana i roto i ngā āhuatanga pH motuhake. Mā te mārama ki ngā tauhohenga matū e uru ana ki te nakunaku ka āwhina i a tātou ki te mārama he aha te momo kai, te āhua o tā tātou kai, me te hauora o ā tātou whekau nakunaku e pā nui ana ki te mimiti matūkai.
1. Ka tīmata te nakunaku i roto i te mangai: te waikura tuatahi o ngā warowaihā
Ko te waha te wāhi tuatahi o te nakunaku matū. Ina ngaungauhia te kai, ka whakaputahia e ngā repe huware te huware kei roto te whākōkī huware amylase (ptyalin). Ka wawahia e te amylase ngā warowaihā matatini pērā i te māngaro ki ngā ngota iti ake, ko te nuinga ko te maltose me te oligosaccharides.
I roto i te ao matū, he tauhohenga waikura tēnei tukanga, arā, te pakaru o ngā hononga matū mā te whakamahi i te wai me te āwhina o ngā whākōkī hei whakakorikori. Ka pakaru haere ngā hononga glycosidic i roto i ngā polysaccharides, ka hua ake he ngota poto ake, he ngota nui ake. Heoi, he poto te warowaihā i roto i te waha nā te mea ka tere te haere o te kai ki roto i te puku, ka whakakorea e ngā āhuatanga waikawa nui te amylase huware.
Kei roto hoki i te huware te paikāponate me ngā momo pūmua tiaki e āwhina ana ki te pupuri i te pH o te waha kia pai ai te mahi a ngā whākōkī. Mā te ngaungau ka nui ake te horahanga o te mata o te kai, ka tere ake ngā tauhohenga matū e whai ake nei nā te mea he māmā ake te uru atu o ngā whākōkī ki ngā matū.
2. Puku: ngā tauhohenga i roto i ngā āhuatanga waikawa me te whakakorenga pūmua
I roto i te puku, ko ngā waikawa me ngā whākōkī te mea nui o te nakunaku matū. Ka whakaputahia e te pakitara o te puku te waikawa hauwaiora (HCl), kia iti rawa ai te pH o te puku (tata ki te 1,5–3). He maha ngā mahi matū nui a tēnei taiao waikawa.
Tuatahi, ka puta te whakakorenga o te pūmua e te HCl. Kāore te whakakorenga e uru ki te wawahi i ngā pūmua ki ngā waikawa amino , engari ko te whakarerekē i te hanganga toru-ahu o te pūmua, ka whakatuwhera i ngā mekameka. Mā tēnei hanganga "tuwhera" ka māmā ake te tapahi a ngā whākōkī i ngā here peptide i te taahiraa e whai ake nei.
Tuarua, ka whakahohehia e te taiao waikawa te whākōkī pepsin. Ka hangaia tuatahitia tēnei whākōkī i roto i te āhua kore mahi, arā, ko te pepsinogen, hei ārai i te puku ki te "nakunaku" i a ia anō. Ka hurihia e te HCl te pepsinogen hei pepsin mā te tukanga whakahohe e uru ana ki te pakaru i ngā wāhanga motuhake o te ngota pepsinogen. Kātahi ka whakahohehia e te Pepsin te waikura o ngā here peptide i roto i ngā pūmua, ka puta he peptide poto ake.
Tuatoru, ka āwhina te HCl ki te patu i ngā moroiti maha e uru ana ki te tinana me te kai. Nō reira, hei tāpiri atu ki tana mahi nakunaku, ka whakahaerehia hoki e ia he "tauhohenga matū" hei tikanga tiaki mō te tinana.
3. Te tūranga o te au: te whakapūtanga ngako hei tukanga ā-tinana-matū
I muri i te wehenga atu i te puku, ka uru te kai (chyme) ki te wāhanga tuatahi o te whekau iti, te duodenum. I konei, ka rerekē haere ngā tauhohenga matū o te nakunaku, tae atu ki ngā wai mai i te repeure me te au o te ate.
Kei roto i te aukume ngā tote aukume e āwhina ana i te whakaemulsification o ngā ngako. He maha ngā wā ka kiia te whakaemulsification he tukanga ā-tinana, engari he tukanga ā-tinana-matū tonu: he pito wairewa-wai (wai-aroha) ngā tote aukume, he pito wairewa-ngako (wai-aroha). Ka whakaitihia e tēnei hanganga te taumahatanga o te mata, ā, ka pakaruhia ngā porowhita ngako nui ki ngā pata iti.
Ehara te whakapūhui i te tauhohenga pakaru hononga matū, engari he mea nui hei whakanui ake i te horahanga o te mata o te ngako kia pai ake ai te mahi a te whākōkī pakaru ngako, te lipase. Ki te kore te whakapūhui, ka puhoi ake te nakunaku ngako nā te mea kāore e ngāwari te whakaranu i te ngako me ngā wai nakunaku wai.
4. Repeure: te pokapū o ngā whākōkī me ngā tauhohenga whakakore waikawa
Ka whakaputa te repe taiaki i te wai repe taiaki kei roto ko te paikāponate (HCO₃⁻) me ngā momo whākōkī. Ka mahi te paikāponate i roto i te tauhohenga whakakore: ka whakakorengia te chyme tino waikawa mai i te puku kia nui ake te kawakore o te pH i roto i te whekau iti (tata ki te 6–8). Ka taea te mārama ngāwari ki te tauhohenga matū ko te taunekeneke o ngā iona H⁺ (waikawa) me te paikāponate hei hanga waikawa waro, kātahi ka pirau hei wai me te hauhā waro. He mea nui tēnei whakakorenga nā te mea he maha ngā whākōkī whekau e mahi pai ana i te pH kūpapa ki te paku kawakore.
Haunga te paikāponate, ka whakaputahia e te repeure ngā whākōkī:
– Mā te amylase repe taiaki ka haere tonu te wairākau o ngā warowaihā hei disaccharides me hei oligosaccharides.
– Ka wahia e te trypsin me te chymotrypsin ngā pūmua/peptides kia iti ake ngā peptides. Ka hangaia ngā mea e rua i roto i ngā āhua kore mahi (trypsinogen me te chymotrypsinogen) ā, ka whakahohehia i roto i te whekau hei ārai i te pakaru o te repe taiaki e ōna ake whākōkī.
– Mā te lipase repeure ka wairōtia ngā triglycerides hei waikawa ngako me ngā monoglycerides (te glycerol me ngā waikawa ngako rānei, i runga i te wāhanga).
– Ka wawahia e te nuclease ngā waikawa karihi (DNA/RNA) hei nucleotides.
Ko te nuinga o tēnei tukanga ko ngā tauhohenga waikura tere-ā-whākī. He motuhake ngā whākī: kotahi te momo whākī ka pakaru noa i ētahi hononga i roto i tētahi matū motuhake, ka taea ai te nakunaku i runga i te huarahi whai kiko me te whai hua.
5. Te whekau iti: te nakunaku whakamutunga me te hanganga o ngā ngota ngota kua rite mō te mimiti
Ka whakaputahia e ngā pakitara o te whekau iti ngā whākōkī "rohe paraihe" (ngā whākōkī mata villi) e whakaoti ana i te nakunaku kia puta he āhua mimiti.
Mō ngā warowaihā:
– Ka wahia e te maltase te maltose kia rua ngā ngota hukahuka.
– Ka wawahia e te sucrase te sucrose hei glucose me te fructose.
– Ka wahia e te lactase te lactose hei kūhuka me te galactose.
He tauhohenga waikura ēnei katoa o ngā disaccharides hei monosaccharides, he momo ka taea te mimiti ki roto i te toto mā roto i ngā pūtau epithelial o te puku.
Mō te pūmua:
– Ka wahia e ngā whākōkī peptidase ngā peptide iti hei waikawa amino. Ko te wehenga o te here peptide he waikura anō ki ngā waeine iti rawa ka taea e te tinana te whakamahi hei hanga kiko hou, homoni, me ngā whākōkī.
Mō te ngako:
– Ka hangaia ngā micelles me ngā tote au e ngā hua o te nakunaku ngako (ngā waikawa ngako, ngā monoglycerides), kātahi ka uru ki ngā pūtau puku. I roto i ngā pūtau, ka taea te whakakotahi anō i ngā wāhanga ngako hei triglycerides, ka tākaihia ki roto i ngā chylomicrons hei uru ki ngā oko toto lymphatic.
6. Te whekau nui: te whakapūtanga o ngā huakita me ngā tauhohenga matū tāpiri
Ahakoa ko te nuinga o ngā matūkai ka mimitihia i roto i te whekau iti, ka uru atu hoki ngā tauhohenga matū ki te whekau nui, ko te nuinga mā roto i ngā mahi a ngā huakita o te puku. Ka whakapūpūtia e ngā huakita ngā muka kāore anō kia nakunaku, ka puta he waikawa ngako mekameka poto pērā i te acetate, te propionate, me te butyrate. Ka taea te mimiti me te whakamahi i ēnei matū hei puna pūngao, ā, he wāhi nui hoki tō rātou ki te hauora o te pakitara o te whekau.
Haunga te whakapūkara, ka mimiti te whekau nui i te wai me ngā electrolytes, ka āwhina i te hanganga o ngā paru. E whakaatu ana tēnei tukanga ehara i te mea ko te wawahi kai anake te mahi a te nakunaku, engari ko te whakahaere anō hoki i te taurite wai o te tinana.
7. Ngā āhuatanga e pā ana ki ngā tauhohenga matū i roto i te nakunaku
He maha ngā āhuatanga e pāngia ai te whai huatanga o ngā tauhohenga matū o te nakunaku:
1. pH: He pH tino pai ngā whākōkī. He pai te mahi a te Pepsin i roto i ngā āhuatanga waikawa, engari ko ngā whākōkī repe taiaki he mahi i roto i ngā āhuatanga kūpapa-kawakore.
2. Mahana: He pai te pāmahana tinana (tata ki te 37°C) mō ngā whākōkī tangata. Ka taea e te kirika nui, ngā āhuatanga kino rānei te whakararuraru i te mahi a ngā whākōkī.
3. Te wātea o ngā whākōkī me ngā matūkai: Ko te korenga o ētahi whākōkī (hei tauira, te lactase) ka puta ai ngā mate nakunaku pērā i te kore e manawanui ki te lactose.
4. Te tere o te whakawātea i te puku me te nekenekehanga o te puku: Ka taea e te tere rawa, te puhoi rawa rānei te whakarerekē i te wā e pā ai ngā whākōkī ki te kai.
5. Hauora o te nakunaku: Ka taea e te mumura, ngā mate ate/repe taiaki, ngā mate puku rānei te whakaiti i te hanga whākōkī, te whakarerekē rānei i te taiao matū.
Te Katinga
Ko ngā tauhohenga matū e uru ana ki te nakunaku he mahi tahi matatini o ngā whākōkī, ngā waikawa, ngā kakano, me ētahi atu matū koiora e puta ana i te waha ki te whekau nui. Mā te waikura o ngā warowaihā, ngā pūmua, me ngā ngako ka whakarite kia hurihia te kai hei ngota ngāwari pēnei i te kūhuka, ngā waikawa amino, me ngā waikawa ngako ka taea e te tinana te mimiti. Ko te whakakorenga o ngā waikawa e te paikāpōnate, te whakapūtanga o ngā ngako e te au, me te whakapūtanga moroiti i roto i te whekau nui e whakaatu ana ko te nakunaku ehara i te mea ko te "wāwāhi kai" anake, engari ko te whakatū hoki i ngā āhuatanga matū tika mō te whakamahinga pai o ngā matūkai. Mā te mārama ki tēnei tukanga, ka taea e tātou te whiriwhiri kai whakaaro nui ake, me te pupuri i tētahi pūnaha nakunaku hauora mō te mimiti pai o ngā matūkai.
