Te Mahi a ngā Alveoli i roto i te Whakawhiti Hau
He mea whakamiharo te pūnaha manawa o te tangata i roto i te hangarau koiora. Ko tētahi o ōna wāhanga tino uaua me te mea nui ko ngā alveoli, arā, ngā pēke hau iti i roto i ngā pukahukahu e āwhina ana i te tukanga nui o te whakawhiti hau. Hei mārama ki te matatau o ngā alveoli, me ruku tātou ki roto i tō rātou hanganga, mahi, me te tūranga e takarohia ana e rātou ki te pupuri i te homeostasis i roto i te tinana.
Hanganga o ngā Alveoli
He iti noa iho ngā hanganga porowhita, he rite ki te poihau kei te pito o ngā bronchioles, arā, ngā ara iti rawa o te ara manawa. Kei roto i ia pukahukahu e 300 miriona ki te 500 miriona alveoli, ā, ko te mutunga iho he mata nui e 70 mita pūrua te rahi, he rite te rahi ki te papa tēnehi.
Kei roto i ia alveolus he pēke angiangi, he angiangi te pakitara, he mea tito mai i tētahi paparanga kotahi o ngā pūtau epithelial e mōhiotia ana ko ngā pūtau alveolar momo I me te momo II. He papatahi ngā pūtau momo I, ā, e kapi ana i te 95% o te mata o te alveolar, he mea nui ki te horapa o te hau. Ahakoa he iti ake ngā pūtau momo II, he mahi nui anō hoki tā rātou, tae atu ki te hanga i te surfactant, he matū lipoprotein e whakaiti ana i te taumahatanga o te mata i roto i ngā alveoli, e ārai ana i a rātou kei hinga, ā, e whakarite ana i te whakawhitiwhiti hau pai.
Kei te taha tonu o ngā pakitara o te alveolar he whatunga matotoru o ngā capillaries—he uaua toto iti e āwhina ana i te whakawhiti hau i waenga i ngā pukahukahu me te toto. Ko te tata o ngā alveoli me ngā capillaries ka hanga i te arai alveolar-capillary, he maha ngā wā he 0.5 ki te 1.5 micrometer noa te matotoru, e āhei ai te horapa pai o ngā hau.
Te Mahi a ngā Alveoli i roto i te Whakawhiti Hau
Ko te whakawhitiwhiti hau te nuinga o te wā ko te whakawhitiwhiti hāora (O₂) me te hauhā waro (CO₂) i waenga i ngā alveoli me te toto. Ka whakahaerehia tēnei whakawhitiwhiti e te horapa māmā, he tukanga e neke ai ngā ngota mai i ngā wāhi he nui ake te kukū ki ngā wāhi he iti iho te kukū.
I te manawa, ka uru te hau ki roto i ngā alveoli, ka whakakīia ki te hāora. Kātahi ka horapa ngā ngota hāora puta noa i te kiriuhi alveolar ki roto i te toto capillary, ka herea ki ngā ngota hemoglobin i roto i ngā toto whero hei kawe puta noa i te tinana. I te wā kotahi, ka horapa te hauhā waro, he hua para pākia, mai i te toto ki roto i ngā alveoli, ka puta mai i reira i te wā e manawa ana.
Ko te kaha akiaki i muri i tēnei horapa hau ko te pikinga pēhanga wāhanga—ka heke te hāora me te hauhā waro i ō rātou pikinga kukū i waenga i ngā alveoli me te toto capillary. Hei tauira, he teitei ake te pēhanga wāhanga o te hāora i roto i ngā alveoli i roto i te toto capillary, ka akiaki i te hāora kia horapa ki roto i te toto, ko te pēhanga wāhanga o te hauhā waro he teitei ake i roto i te toto i roto i ngā alveoli, ka arahi ki tōna horapa ki roto i ngā alveoli.
Te Hiranga o te Surfactant me te Mata
Kāore e taea te whakanui rawa i te mahi a ngā surfactants i roto i tēnei tukanga. Nā ngā pūtau alveolar momo II i whakaputa, ka tino whakaitihia e te surfactant te taumahatanga o te mata i roto i ngā alveoli. He mea nui tēnei whakaiti hei pupuri i te pumau o ngā pēke alveolar, inā koa i ngā huringa manawa e uru ana ki te whakakī me te whakakore i ngā alveoli.
Ki te kore he surfactant, ka hinga ngā alveoli, inā koa i te wā e tukuna ana te manawa. Nā te kukū o te mata o te wai e whakakī ana i ngā alveoli tēnei āhuatanga, ka puta he kaha hei hinga i ngā alveoli. Ka whakararu te surfactant i tēnei kaha, ka taea ai e ngā alveoli te noho tuwhera, ā, ka whakarite kia haere tonu te whakawhitiwhiti hau.
Te Tūranga o te Rere o te Toto i roto i te Whakawhitinga Hau
Ko te whakawhiti hāora me te hauhā waro e whakawhirinaki nui ana ki te rere o te toto i roto i te pūkahukahu—te rere o te toto mai i te ngākau ki ngā pūkahukahu me te hoki whakamuri. Ko te toto kore-hāora, e hoki mai ana i te rere o te toto pūnaha, ka papuhia e te ventricle matau o te ngākau ki roto i ngā uaua pūkahukahu. Ka peka atu ēnei uaua ki ngā capillaries e karapoti ana i ngā alveoli.
Kia whakakīia te toto i te atanga alveolar ki te hāora mā te tohanga, ka kohia e ngā uaua pūkahukahu ka whakahokia ki te atrium maui o te ngākau, mai i reira ka papua ki te tohanga toto whānui hei tuku hāora ki ngā kiko me ngā whekau.
Hononga Hau-Huru
Mō te whakawhitiwhiti hau tino pai, he mea tino nui te taurite i waenga i te whakapūngao (te hau e tae atu ana ki ngā alveoli) me te toto e tae atu ana ki ngā alveoli mā roto i ngā capillaries. Mā tēnei taurite, e mōhiotia ana ko te hononga whakapūngao-toto, ka whakarite kia ōrite te rere o te toto ki te rere o te hau i roto i ngā alveoli, ka whakanui ake i te whai huatanga o te whakawhitiwhiti hau.
He maha ngā tikanga ā-tinana e whakahaere ana i tēnei hononga. Hei tauira, ko ngā wāhi o te pukahukahu e whiwhi ana i te iti o te hāora (kāore i te pai te hau) ka whakaoho i te vasoconstriction—te whakawhāiti i ngā oko toto—kia tahuri ai te rere o te toto ki ngā wāhi he pai ake te hau. I tetahi atu taha, ko ngā wāhi he pai te hau ka akiaki i te vasodilation—te whānui o ngā oko toto—kia nui ake ai te rere o te toto i aua wāhi. Mā tēnei urupare urutau ka whakarite kia whakaritea ngā alveoli e pai ana te hau mō te rere o te toto, kia pai ake ai te pai o te whakawhiti hau.
Ngā Take e Pā Ana ki te Whakawhiti Hau
He maha ngā āhuatanga ka pā ki te whai huatanga o te whakawhiti hau i roto i ngā alveoli. Ko ētahi o ēnei:
1. Te Horahanga o te Mata: Ko tētahi āhuatanga e whakaiti ana i te maha o ngā alveoli e mahi ana, pērā i te emphysema, ka whakararu i te whakawhiti hau.
2. Te Matotoru o te Ārai Alveolar-Capillary: I roto i ngā mate pēnei i te fibrosis pūkahukahu, ka aukati te matotoru o tēnei ārai i te horapa o ngā hau, ka whakaiti i te whai huatanga o te whakawhiti hau.
3. Ngā Āhuatanga Pēhanga Wāhanga: Ka taea e te teitei, ētahi āhuatanga hauora, te hauhautanga kore rānei te whakaiti i ngā āhuatanga pēhanga wāhanga e tika ana mō te horapa.
4. Te Rere o te Toto: Ko te ngoikore o te tohanga toto o te pūkahukahu, e kitea ana i roto i ngā āhuatanga pēnei i te pulmonary embolism, ka tino aukati i te rere o te toto ki ngā alveoli, ka whakararu i te whakawhiti hau.
5. Te Hanganga o te Kaihoroi: Ko te korenga o te hanganga o te kaihoroi, e kitea ana i roto i ngā pēpi i whānau wawe, i ētahi mate pūkahukahu rānei, ka hua ake te hinganga o te arai me te raruraru o te whakawhiti hau.
Opaniraa
Mā te mārama ki te mahi a ngā alveoli ka mārama te āhua uaua engari he huatau o ngā tukanga ā-tinana e āhei ai te ora. He mea nui ēnei hanganga ririki hei whakarite kia tae atu te hāora ki ō tātou kiko, me te tango pai i te hauhā waro. He mea nui te tiaki me te pupuri i te hauora o ngā alveoli, e whakaatu ana i te hiranga o ngā mahi pēnei i te karo i te momi hikareti, te whakahaere i ngā mate mau tonu, me te whakarite kia tika te tiaki i te wā e hapu ana hei ārai i ngā raruraru e pā ana ki ngā alveoli.
I roto i te poto, ko te mahi a ngā alveoli i roto i te whakawhiti hau he tohu i ngā hoahoa uaua me te whai hua o te tinana tangata, e whakaata ana i te taurite ngawari e tautoko ana i tō tātou oranga tonutanga.
