Eziqhelekileyo, ezongezelelweyo, kunye neziphumo ezenzileyo zeV / Q
I-V / Q i-defmatch impazamo eyenzeka emiphakeni apho umoya wokutshatyalaliswa (ukutshintshwa komoya phakathi kwemiphunga kunye nemozulu) kunye nokuxutywa (ukuhamba kwegazi emiphakeni) akuhambelani ngokufanayo, uphawu oluqhelekileyo lwesifo esingapheliyo se-pulmonary disease ( COPD ).
Yintoni iV / Q echaza
Ngaphambi kokuxoxa ngento eyenzekayo kwiV / Q engafanelekanga, kubalulekile ukuchaza ngokucacileyo ukuba iV / Q ithetha ntoni:
- Limela umoya wokuphefumula , umoya ophefumlelweyo ngempumlo nasemlonyeni, phantsi kwe-trachea, kwi-bronchi, kwaye emva koko uhambe ngeendlela ezincinane zomoya oya kwindlela encinci ye-airway ebizwa ngokuba yi-alveoli apho utshintshi lwe-oxygen ne-carbon dioxide lwenzeka khona .
- I-Q imele ukucoca okanye ukuhamba kwegazi. Ukusuka entliziyweni, i-deoxygenated ("i-blue blue") idlula kwimithambo ye-pulmonary (efana nemithanjeni ngenxa yokuba igazi idinga i-oksijeni) ngeempahla ezincinci kunye ezincinci kunye neepillari (iinqwelo ezincinci zegazi) apho i-oksijeni kunye neshintsho ithatha indawo.
I- alveoli yincinci ye-airways, enye iseli enye. Ngasemva kwe-alveoli kukho i-capillary, encinci yemithambo yegazi kunye neseli elilodwa kuphela. Le yindawo apho utshintshi lwe-oksijini kunye nekhabhoni yenzeka emiphakeni, njengoko i-oksijini idlula kwi-alveoli eya kwi-capillaries, kwaye i-carbon dioxide idlula kwi-capillaries iya kwi-alveoli.
I-V / Q okanye u-ventilation / perfusion ibhekisela kwisixa somoya esifike kwi-alveoli esahlukisiwe ngumlinganiselo wegazi ogqithisa kwi-capillaries emiphakeni.
Ukuqonda indawo yokufa
Kubalulekile ukuza kuchaza "indawo efile." Oku kubhekisela kuyo nayiphi na indawo apho i-alveoli kunye nama-capillari azinzi.
Esi sithuba esifileyo singaba:
- Indawo efile ye-Anatomical, ngenxa yokuphazamiseka kwendlela yokuhamba ngomoya okanye ukunikezelwa kwegazi, njenge- pulmonary emboli (ukuvimbela umkhumbi wegazi) okanye umzimba ongaphandle ungeniswe kwindlela yokuhamba.
- Indawo efileyo yendalo, eyenzekayo xa izakhiwo zomoya okanye imithwalo yegazi ziqhelekileyo, kodwa zikho ezinye izizathu zokuba i-alveoli ne-capillaire ayifani ngokufana nokukhupha igazi ngaphandle kwendawo ethile yemiphunga (ukukhutshwa komzimba) .
Ngendawo efile, ngokuqinisekileyo uzisa igazi kwindawo engakwazi ukuyithatha i-oksijeni, okanye ukuzisa umoya kwindawo engakwazi ukukhipha umoya-mpilo.
Ukulinganisa iV / Q Ratio
Ukulinganisa umlinganiselo weV / Q kwenziwa ngeemvavanyo ezimbini ezihlukeneyo. Ukulinganisa umoya wokungena umoya, umntu unemaski ebekwe phezu kobuso bakhe aze aphefumle emoyeni omsakazo. Ukulinganisa i-perfusion, iprotheni e-radioactive ifakwe kwi-vein. Emva koko iziphumo zale mvavanyo emibini zifaniswa.
Ziyintoni i-V / Q yokuThathisa
I-V / Q i-mismatch ithetha ukuba kwezinye iindawo zemiphaphu, i-alveoli kunye ne-capillaire ayinakunqumla okanye kukho indawo efile. Oku kunokuthetha ukuba kwezinye iindawo zomphunga, zikhona i-capillaries ezingaphezu kwe-alveoli, ngamanye amagama, indawo kwimiphunga ephuculwe yicala ngaphezu kwempompo.
Kweminye imimandla, kunokubakho ngaphezulu kwe-alveoli ne-oksijini elitsha kunama-capillari ukuze athathe i-oxygen. Ngamanye amazwi, ezinye iindawo zemiphunga zingaphumelela ngokomoya ngaphezu kokucatshiswa.
Elinye izinga lokungahambi kakuhle lenzekile ngokuqhelekileyo, kodwa xa likhula ngaphaya kwendawo ethile, kubangela iingxaki. Kutheni iV / Q ixubusha ingxaki? I-V / Q i-mismatch yiyona nto ibangelwa yi- hypoxemia kunye nenxalenye yezona zinto ezibangela ukuhluleka ukuphefumula.
I-Hypoxemia yegama elibhekiselele kumgangatho wehla we-oksijini egazini. Xa iiseli zomzimba zithintela i-oksijeni (kwaye zonakaliswe kwaye ekugqibeleni ziyafa) ngenxa ye-hypoxemia, kuthiwa yi-hypoxia.
Iimpawu ze-hypoxia inokuphelelwa amandla, ukuphefumula okufutshane, ukudideka, kunye nokungahambi, ukufa.
Izizathu zeV / Q Ukuxhatshazwa
I-V / Q i-mismatch ingabangelwa yiyiphi into eyenza ukwandisa okanye ukunciphisa ukungena kwemiphunga okanye ukwanda okanye ukunciphisa ukuhluthwa kwemiphunga. Ngamanye amagama, nantoni na ephazamisa umoya ophelileyo ukufikelela kwi-alveoli, okanye nayiphi na into evimbela igazi ukugeleza kwi-capillaries. Zombini ezi zinto zingaphazamisa ukulinganisela phakathi kokungenisa umoya kunye nokunyusa.
Eziqhelekileyo, ezinciphileyo, kunye nokwandiswa kweeVati kunye neeRatiyo
Umlinganiselo oqhelekileyo weV / Q u-0.80. Oku kuthetha ukuba malunga neekitha ezingama-4 ze-oksijini zidlula emiphakeni nganye ngomzuzu ngelixa ama-5 ilitha egazi adlula emiphakeni.
Umlinganiselo we- V / Q owehlayo kwenzeka xa kukho nciphisa ukuphuphuma umoya kwimiphunga okanye ukwanda kwamanzi (ukuphuma kwegazi ngaphezulu kumaphaphu). Iimeko ezingabangela ukuba umlinganiselo we-V / Q wehla uquka:
- I-bronchitis engapheliyo : Ukuhlanganiswa kwe- bronchospasm , i-mucus plugs, ukuvuvukala, kunye nokuvinjelwa kwe-air all add to worsening ventilation kwaye ngokunjalo ukunciphisa umlinganiselo wokuphuphuma umoya.
- Isifuba
- Edema
- Ukuvinjelwa kwe-Airway (ukufunwa komzimba wangaphandle)
Umlinganiselo wokwandiswa kweV / Q uyenzeka xa kukho ukunyuka kwomoya okanye ukunciphisa umonakalo (ukuhamba kwegazi ukuya kumaphaphu.) Umlinganiselo wokwandiswa kweV / Q ungabonwa nge:
- Ukugqithiswa kwepulmonary: Ukuxhamla kwe-pulmonary i-blood clot emiphakeni edla ngokuqala njengegazi lemilo emilenzeni eyahlukanayo kwaye iya kwiipapu. Ukuba likhulu ngokwaneleyo, i-clot ingayigcina isitya esipheleleyo segazi esenza ukuba kungabikho mveliso kwiindawo ezithile zomphunga ezifumana umoya. Ngenxa yoko i-V / Q iyanda ngenxa yokuba umoya (V) uhlala ufana kunye kunye nokuqhathaniswa (Q) kwehla. Kuvavanyo lweV / Q, kuya kubakho ubungqina bokuba amacandelo omphunga ekuhanjisweni kwegazi elichaphazelekayo ayapheliswa.
- I-Emphysema : I-Emphysema inokubangela ukuba nomlinganiselo ophezulu we-V / Q. Ngenxa ye-alveoli ewonakalisiweyo neyitshabalalisa kwimiphunga, indawo ekhoyo yokudluliselwa kwe-oxygen ne-carbon dioxide iyahla. Ngenxa yoko, ukunyuka kwamanzi kuya kunyuka, okukhokelela kwinqanaba elongezelelweyo leV / Q.
Imithombo:
Jobse, B., McCurry, C., Morissette, M. et al. Impact of Inflammation, Emphysema, kunye nokuCima ukuCima kwiV / Q kwiMouse Models ye-Lung Obstructing. Uphando loPhepha . 2014. 15:42.
ILayibrari yeSizwe ka-US yamayeza. MedlinePlus. I-Pulmonary Ventilation / Perfusion Scan. https://www.nlm.nih.gov/medlineplus/ency/article/003828.htm.