Tikanga Whakahaere pH Tinana
Ka mahi pai te tinana tangata i roto i tētahi whānuitanga pumau o ngā āhuatanga o roto. Ko tētahi o ngā tawhā tino nui me pupuri tonu ko te pH, he ine i te waikawa, i te matū rānei (karaka) o tētahi otinga. I roto i te tangata, ko te pH toto noa kei te 7,35–7,45. He māmā noa iho tēnei tau, engari ahakoa he iti noa te rerekētanga ka taea te whakararuraru i te mahi whākōkī , te pākia o ngā pūtau, te mahi io, me te whakahekenga o te uaua o te ngākau. Nō reira, he maha ngā paparanga o te tinana, he tere, he tautoko tahi hoki.
Te mārama ki te pH me te hiranga o te taurite waikawa-pūtake
Ka whakatauhia te pH e te kukū o ngā katote hauwai (H⁺) i roto i ngā wai o te tinana . Ko te teitei ake o te H⁺, ko te nui ake o te waikawa; ko te iti iho o te H⁺, ko te nui ake o te taketake. He maha ngā tauhohenga matū i roto i te tinana ka puta he waikawa me he turanga hei hua taha. Hei tauira, ka puta he hauhā waro (CO₂) i roto i te pākia o te warowaihā me te ngako, ka taea te hanga waikawa waro, ko te pākia o te pūmua ka puta he waikawa kore-pūngoi pērā i te waikawa whanariki me te waikawa phosphoric.
He aha te mea nui kia mau tonu te pH o te toto? He pH tino pai ngā whākōkī—ngā pūmua e tere ake ai ngā tauhohenga matū koiora. Ka taea e ngā huringa o te pH te whakarerekē i te hanganga pūmua , te pā ki ngā hononga matū, me te whakarerekē i te mahi a ngā kaiwhakawhiwhi me ngā hongere katote. Nō reira, ka pāngia ngā pūnaha tinana e te ngoikore. Ka taea e te waikawa (he pH iti rawa) te whakaheke i te kaha o te ngākau, te arrhythmias, me te whakaheke i te urupare toto ki ngā catecholamines. Ka taea e te alkalosis (he pH teitei rawa) te whakaputa i ngā tohu pēnei i te ngau, te mamae, tae atu ki ngā raruraru manawa o te ngākau nā ngā huringa o te here o te konupūmā ki ngā pūmua.
Ngā pūtake o ngā waikawa me ngā kawakore i roto i te tinana
E rua ngā pūtake matua e whakaputahia ana e te tinana ngā "waikawa". Tuatahi, ko ngā waikawa pūngāwerewere, i roto i te āhua o te CO₂, ka puta mā te manawa pūtau. Ka ngāwari te whakaputa i te CO₂ e ngā pukahukahu, nō reira te kupu pūngāwerewere. Tuarua, ko ngā waikawa kore-pūngāwerewere (ngā waikawa pumau) ka ahu mai i te pūmua me te pākia o te phospholipid, pērā i te waikawa whanariki me te waikawa phosphoric. Kāore e taea te whakaputa i ngā waikawa kore-pūngāwerewere mā roto i ngā pukahukahu, ā, ka whakawhirinaki ki ngā whatukuhu mō te whakaputanga.
I tētahi atu taha, ka whakaputahia hoki e te tinana ngā turanga, ko tētahi o ēnei ko te paikāponate (HCO₃⁻), he mahi nui tēnei hei ārai matua i roto i te toto toto. Ka puritia tēnei taurite i waenga i ngā waikawa me ngā turanga e te pūnaha whakahaere pH.
E toru ngā pou o te whakahaere pH: ngā pūkahukahu, ngā pūkahukahu, me ngā whatukuhu
E toru ngā arai matua mō te whakahaere i te pH o te tinana:
1. Pūnaha ārai matū (tere rawa, mahi i roto i ngā hēkona)
2. Pūnaha manawa (tere, meneti ki ngā hāora)
3. Pūnaha whatukuhu (tino kaha engari puhoi, mai i ngā hāora ki ngā rā)
Ka mahi tahi ēnei e toru ki te pupuri i te pumau o te pH o te toto ahakoa ngā panonitanga o te hanga waikawa-pūmua.
1) Pūnaha ārai matū: te rārangi tuatahi o te parenga
He takirua waikawa-pūtake ngoikore te parepare e ātete ana i ngā huringa o te pH mā te "hopu" me te "tuku" rānei i ngā iona H⁺. Kāore ngā parepare e tango i te waikawa mai i te tinana, engari ka whakau i te pH mō te wā poto kia wātea ai ētahi atu pūnaha ki te whakarerekē.
Pūwero paikāpōnati (HCO₃⁻/H₂CO₃)
Ko te pūnaha paikāponate te mea tino nui o te pūhui toto, e uru ana ki ēnei tauhohenga:
CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻
Ina piki te H⁺ (ka piki te waikawa), ka herea e te HCO₃⁻ te H⁺ hei hanga i te H₂CO₃, ka taea te huri hei CO₂ ka tukuna atu mā roto i ngā pukahukahu. I tetahi atu taha, ina heke te H⁺ (he tino taketake rawa), ka taea e te H₂CO₃ te pirau hei hanga i te H⁺ hei whakaheke anō i te pH.
Ko te painga o tēnei pūnaha, e rua ngā whekau e āhei ai te whakahaere i ōna wāhanga: ko ngā pūkahukahu e whakahaere ana i te CO₂, ā, ko ngā whatukuhu e whakahaere ana i te HCO₃⁻.
Hemoglobin pūwero me ngā pūmua plasma
He kaha te ārai i te toto toto whero, nā te mea ka taea e ia te here i te H⁺. Ina uru te CO₂ ki ngā toto toto whero, ka hurihia ētahi o aua mea e te whākōkī carbonic anhydrase hei H⁺ me te HCO₃⁻. Kātahi ka herea te H⁺ e te toto toto, ā, kāore e tino whakanuia te waikawa o te toto. He rōpū waikawa-pūtake anō hoki ō ngā pūmua toto ka taea te ārai i ngā huringa pH, ahakoa he iti ake tā rātou takoha i tō te toto toto toto.
Pūmau Phosphate
Ko te pūnaha phosphate (H₂PO₄⁻/HPO₄²⁻) te mea nui ake i roto i i roto i te pūtau me te wai ngongo whatukuhu. He mea tino nui tēnei ārai i roto i te te tukanga whakaputa waikawa e ngā whatukuhu, nā te mea ka taea e te phosphate te "pupuri" i te H⁺ i roto i te mimi.
2) Te whakahaere a ngā pukahukahu: te whakahaere i te CO₂
Ka whakahaere ngā pukahukahu i te pH mā te whakahaere i te nui o te CO₂ e tukuna ana mā te whakapūhau. Nā te mea he hononga tika te CO₂ ki te hanganga o te H⁺ i roto i te tauhohenga paikāpōnate, ka pāngia te pH toto e ngā panonitanga o te whakapūhau.
– Ki te waikawa te toto (waikawa): ka whakanuia e te tinana te manawa (whakapūngahau nui) kia nui ake ai te CO₂ e tukuna ana. Mā te hekenga o te CO₂ ka nekehia te tauhohenga ki maui, ka heke te H⁺, ka piki ake hoki te pH.
– Ki te tino kawakore te toto (alkalosis): ka pōturi te whakapūngao (hypoventilation) kia mau tonu ai te CO₂, ka neke te tauhohenga ki te taha matau, ka piki te H⁺, ka heke te pH ki te tata noa.
Ka whakahaeretia tēnei mana whakahaere e te pokapū manawa i roto i te kakau roro, e whiwhi ana i ngā tohu mai i ngā chemoreceptors. He tairongo ngā chemoreceptors pokapū ki ngā huringa o te CO₂ (mā ngā huringa o te pH wai cerebrospinal), ko ngā chemoreceptors taha (i roto i ngā tinana carotid me te aorta) he tairongo ki te pH toto me ngā taumata hāora.
Heoi, he rohe kei te pūnaha manawa . Mā te nui rawa o te korenga o te manawa ka arahi pea ki te korenga o te hāora (hypoxia). Nō reira, kāore e taea te haere tonu te utu manawa mō te alkalosis.
3) Te whakahaere a ngā whatukuhu: te whakahaere i te whakaputanga paikāpōnate me te waikawa
Ko ngā whatukuhu ngā kaiwhakahaere mō te taurite waikawa-pūtake mō te wā roa. I te nuinga o te wā, e toru ngā huarahi matua e pupuri ai ngā whatukuhu i te pH:
1. Te mimiti anō o te paikāpōnate kua tātarihia (HCO₃⁻)
2. Te Tukunga o ngā iona H⁺
3. Te hanganga o te paikāpōnati hou (HCO₃⁻ hou) hei whakakapi i te mea i whakamahia hei whakakore i te waikawa.
Te mimiti anō o te paikāponate
Ko te nuinga o te HCO₃⁻ i roto i te toto toto ka tātarihia i te glomerulus. Me "whakahoki" e ngā whatukuhu te HCO₃⁻ kia kore ai e ngaro i roto i te mimi. I roto i te ngongo proximal, ka tukuna e ngā pūtau ngongo te H⁺ ki roto i te lumen ngongo. Ka honoa tēnei H⁺ ki te HCO₃⁻ hei hanga i te H₂CO₃, ka pakaruhia hei CO₂ me te H₂O. Ka horapa anō te CO₂ ki roto i ngā pūtau ngongo, ā, ka hurihia anō hei HCO₃⁻, ka whakahokia ki te toto. Mā tēnei tikanga ka pupuri i ngā rahui paikāponate.
Te tukunga o te waikawa hei waikawa titrated me te ammonia
E rua ngā āhua o te whakaputanga o te H⁺ e ngā whatukuhu:
– Te waikawa titration (ina koa ko te phosphoric): Ka herea te H⁺ e te HPO₄²⁻ hei hanga i te H₂PO₄⁻ ka tukuna ki roto i te mimi.
– Ammonia (NH₄⁺): Ka wahia e ngā whatukuhu te glutamine hei whakaputa i te NH₃ (amonia), ka herea ki te H⁺ hei hanga i te NH₄⁺. He mea nui tēnei tukanga ina pāngia te tinana e te waikawa pūmau nā te mea ka taea e ia te whakanui ake i te kaha ki te tango waikawa.
Ko te H⁺ e tangohia ana hei NH₄⁺, hei H₂PO₄⁻ rānei, e pā ana ki te hanganga o tētahi HCO₃⁻ hou ka whakahokia ki te toto, ā, ka āwhina i te whakapiki i te pH.
Te ariā o te utu: ina whakararuraruhia tētahi pūnaha
Ko ngā mate waikawa-pūtake ka wehea whānuitia kia:
– Ngā mate manawa: ngā huringa tuatahi o te CO₂ (hei tauira, te ngoikore o te manawa → te waikawa o te manawa; te nui o te manawa → te alkalosis manawa).
– Ngā mate pāwera: ngā huringa tuatahi o te HCO₃⁻, te kawenga waikawa rānei (hei tauira, te mate korere nui ka ngaro te paikāpōnate → te waikawa pūmua; te ruaki roa ka ngaro te waikawa puku → te alkalosis pūmua).
Ka whakatikatika te tinana mā roto i ētahi atu pūnaha: ka whakatikatikaina ngā raruraru pākia e ngā pukahukahu (ka whakarerekē i te hau), ko ngā raruraru manawa ka whakatikatikaina e ngā whatukuhu (ka whakarerekē i te mimiti anō o te HCO₃⁻ me te whakaputanga H⁺). Ka āwhina te whakatikatika i te pH kia tata ake ki te noa, engari kāore e tino whakahokia mai kia whakatikahia rā anō te take matua.
Te Katinga
Ko te whakahaere pH o te tinana he tauira pai o te tika o te pūnaha homeostasis tangata. Ka mahi ngā ārai matū i roto i ngā hēkona hei ārai i ngā huringa pH, ka tere te whakarite a ngā pukahukahu i te CO₂ mā roto i ngā huringa o te hauhautanga, ā, ka kaha te whakahaere a ngā whatukuhu i te tukunga waikawa me ngā rahui paikāponate hei pupuri i te pumau mō te wā roa. Ka tautokohia e ēnei pūnaha e toru tetahi ki tetahi, ka pupuri i te pH toto i roto i te awhe whaiti e taea ai e ngā pūtau te mahi pai. He mea nui te mārama ki ēnei tikanga ehara i te mea mō te koiora me te rongoā anake, engari mō te mōhio hoki me pēhea te pānga whānui o ngā raruraru iti o te manawa, te mahi whatukuhu, te pākia rānei ki te hauora o te tinana katoa.
