Kev noj cov as-ham rau hauv tib neeg lub cev thiab kev tawm ntawm cov khoom lag luam metabolic yog ua los ntawm tib neeg lub cev excretory. Kev ua haujlwm ntawm lub cev ntawm tib neeg lub cev excretory muaj nws tus kheej cov txheej txheem rau kev tshem tawm cov khoom metabolic, uas yog pom, reabsorption thiab secretion, tsim nyob rau hauv cov txheej txheem ntawm evolution.
Human excretory system
Kev tshem tawm cov khoom lag luam metabolic los ntawm lub cev yog ua los ntawm cov kabmob ntawm lub cev, uas muaj ob lub raum, ureters, zais zis thiab urethra.
Lub raum nyob rau hauv qhov chaw retroperitoneal hauv thaj tsam lumbar thiab yog taum zoo li.
Qhov no yog ib qho khoom ua ke, muaj lub cortex thiab lub medulla, lub plab mog, thiab nws yog npog nrog ib daim nyias nyias. Lub pelvis ntawm lub raum muaj ib lub tais me me thiab loj, thiab lub ureter tawm ntawm nws, uas xa cov zis mus rau lub zais zis thiab los ntawm lub urethra, cov zis kawg yog tawm ntawm lub cev.
Lub raum koom nrog cov txheej txheem metabolic, thiab lawv lub luag haujlwm hauv kev ua kom lub cev dej sib npaug, tswj cov kua qaub-puag yog qhov tseem ceeb rautag nrho tib neeg lub neej.
Cov qauv ntawm lub raum yog qhov nyuaj heev thiab nws cov qauv tsim yog nephron.
Nws muaj cov qauv tsim thiab muaj cov kwj dej ze, lub cev nephron, lub voj ntawm Henle, cov kwj dej distal thiab cov kav dej sib sau, uas ua rau cov ureters. Reabsorption nyob rau hauv ob lub raum kis tau los ntawm cov tubules ntawm proximal, distal thiab voj ntawm Henle.
Reabsorption mechanism
Molecular mechanisms ntawm kev nkag mus ntawm cov tshuaj nyob rau hauv cov txheej txheem ntawm reabsorption yog:
- diffusion;
- endocytosis;
- pinocytosis;
- passive thauj;
- kev thauj mus los.
Qhov tseem ceeb tshwj xeeb rau reabsorption yog kev ua haujlwm thiab kev thauj mus los thiab kev taw qhia ntawm cov tshuaj reabsorbed raws li electrochemical gradient thiab muaj cov cab kuj rau cov khoom, kev ua haujlwm ntawm cov twj tso kua mis ntawm tes thiab lwm yam ntxwv.
Kev thauj khoom nquag mus tawm tsam electrochemical gradient nrog kev siv hluav taws xob rau nws qhov kev siv thiab los ntawm kev thauj tshwj xeeb. Qhov xwm ntawm kev txav yog transcellular, uas yog ua los ntawm kev hla lub apical membrane thiab basolateral ib. Cov tshuab no yog:
- Kev thauj mus los tseem ceeb, uas tau ua nrog kev pab ntawm lub zog los ntawm kev tawg ntawm ATP. Nws yog siv los ntawm Na+, Ca+, K+, H+ ions.
- Kev thauj mus los thib ob tshwm sim vim qhov sib txawv ntawm qhov sib txawv ntawm sodium ions hauv cytoplasm thiab hauv lumen ntawm cov tubules, thiab qhov sib txawv no tau piav qhia los ntawm kev tso tawm ntawm sodium ions mus rau hauv cov kua nruab nrog cev.kev siv zog ntawm ATP splitting. Nws siv cov amino acids, qabzib.
Kev thauj mus los tsis tu ncua khiav raws gradients: electrochemical, osmotic, concentration, thiab nws qhov kev siv tsis xav tau lub zog thiab tsim cov cab kuj. Cov tshuaj uas siv nws yog Cl-ions. Lub zog ntawm cov khoom yog paracellular. Qhov no yog txav mus thoob lub cell membrane, uas nyob nruab nrab ntawm ob lub hlwb. Cov yam ntxwv molecular mechanisms yog diffusion, thauj nrog cov kuab tshuaj.
Cov txheej txheem ntawm cov protein reabsorption tshwm sim hauv cov kua hauv cellular, thiab tom qab faib nws mus rau hauv cov amino acids, lawv nkag mus rau hauv cov kua dej intercellular, uas tshwm sim los ntawm pinocytosis.
Type of reabsorption
Reabsorption yog txheej txheem uas tshwm sim hauv cov tubules. Thiab cov khoom uas dhau los ntawm cov tubules muaj cov khoom sib txawv thiab cov txheej txheem.
Nyob ib hnub, ob lub raum tsim los ntawm 150 mus rau 170 litres ntawm cov zis thawj, uas mus dhau cov txheej txheem ntawm reabsorption thiab rov qab mus rau lub cev. Cov khoom uas muaj cov khoom tawg yooj yim tsis tuaj yeem dhau los ntawm daim nyias nyias ntawm cov tubules thiab, nyob rau hauv tus txheej txheem ntawm reabsorption, nkag mus rau hauv cov ntshav nrog lwm yam tshuaj.
Proximal Reabsorption
Nyob rau hauv lub zeem muag nephron, uas nyob rau hauv lub raum cortex, reabsorption tshwm sim rau qabzib, sodium, dej, amino acids, vitamins thiab protein.
Cov tubule ze ze yog tsim los ntawm cov hlwb epithelial uas muaj cov apical membrane thiab txhuam ciam teb, thiabNws raug coj mus rau lub lumen ntawm lub raum tubules. Hauv qab daus daim nyias nyias ua folds uas tsim lub basal labyrinth, thiab los ntawm lawv cov zis thawj nkag mus rau peritubular capillaries. Cov hlwb sib txuas ua ke nruj thiab tsim ib qho chaw uas khiav thoob plaws hauv qhov chaw intercellular ntawm lub tubule, thiab nws yog hu ua basolateral labyrinth.
Sodium yog reabsorbed nyob rau hauv ib tug complex peb-kauj ruam txheej txheem thiab yog ib tug cab kuj rau lwm yam tshuaj.
Reabsorption ntawm ions, qabzib thiab amino acids nyob rau hauv lub tubule proximal
Cov kauj ruam tseem ceeb hauv sodium reabsorption:
- Kev hla dhau ntawm daim nyias nyias. Qhov no yog theem ntawm kev thauj mus los ntawm sodium, los ntawm Na-channels thiab Na-carriers. Sodium ions nkag mus rau hauv lub cell los ntawm membrane hydrophilic proteins uas tsim Na-channels.
- nkag lossis nkag los ntawm daim nyias nyias yog txuam nrog kev sib pauv ntawm Na + rau hydrogen, piv txwv li, lossis nrog nws nkag los ua cov khoom nqa ntawm qabzib, ib qho amino acid.
- Kev hla hauv qab daim nyias nyias. Qhov no yog theem ntawm kev thauj mus los ntawm Na +, los ntawm Na + / K + twj nrog kev pab los ntawm enzyme ATP, uas, thaum tawg, tso tawm lub zog. Sodium, raug reabsorbed nyob rau hauv lub raum tubules, yog tas li rov qab mus rau cov txheej txheem metabolic thiab nws cov concentration nyob rau hauv lub hlwb ntawm cov tubule proximal yog tsawg.
Reabsorption ntawm qabzib dhau los ntawm kev thauj mus los theem nrab thiab nws cov khoom noj tau yooj yim los ntawm kev xa mus los ntawm Na-pump, thiab nws rov qab mus rau cov txheej txheem metabolic hauv lub cev. Cov piam thaj ntau ntxiv tsis yog tag nrho reabsorbed hauv lub raum thiab tawm nrogtso zis kawg.
Reabsorption ntawm amino acids pib zoo ib yam li qabzib, tab sis lub koom haum complex ntawm amino acids yuav tsum muaj kev koom tes ntawm tshwj xeeb transporters rau txhua amino acid tsawg tshaj li 5-7 ntxiv.
Reabsorption nyob rau hauv lub voj ntawm Henle
Lub voj ntawm Henle hla dhau lub medulla ntawm lub raum, thiab cov txheej txheem ntawm reabsorption hauv qhov nce thiab nqis ntawm nws txawv rau dej thiab ions.
Cov lim dej, nkag mus rau hauv qhov nqis los ntawm lub voj, nqis los ntawm nws, tso dej vim qhov sib txawv ntawm qhov sib txawv thiab yog saturated nrog sodium thiab chlorine ions. Hauv qhov no, dej yog reabsorbed, thiab nws yog impermeable rau ions. Qhov nce toj yog impermeable rau dej thiab thaum hla dhau nws, thawj cov zis yog diluted, thaum nyob rau hauv ib tug nqis los nws yog concentrated.
Distal Reabsorption
Qhov no ntawm nephron nyob rau hauv lub cortex ntawm lub raum. Nws txoj haujlwm yog kom rov nqus dej uas tau sau hauv thawj cov zis thiab rov nqus cov sodium ions. Distal reabsorption yog dilution ntawm thawj cov zis thiab tsim cov zis kawg los ntawm cov filtrate.
Nkag mus rau hauv lub tubule distal, thawj cov zis ntawm 15% tom qab reabsorption hauv lub raum tubules yog 1% ntawm tag nrho cov ntim. Tom qab ntawd muab tso rau hauv lub ducts, nws dilutes, thiab cov zis zaum kawg yog tsim.
Neurohumoral kev cai ntawm reabsorption
Reabsorption nyob rau hauv lub raum yog tswj los ntawm lub sympathetic paj hlwb thiab thyroid, hypothalamic-pituitary thiab androgens.
Reabsorption ntawm sodium, dej, qabzibnce nrog excitation ntawm sympathetic thiab vagus qab haus huv.
Distal tubules thiab sau cov ducts reabsorb dej hauv lub raum raws li kev cuam tshuam ntawm antidiuretic hormone los yog vasopressin, uas nce ntau nrog cov dej hauv lub cev, thiab tseem ua rau cov phab ntsa ntawm cov tubules nce ntxiv.
Aldosterone tsub kom reabsorption ntawm calcium, chloride thiab dej, zoo li atriopeptide, uas yog tsim nyob rau hauv txoj cai atrium. Inhibition ntawm sodium reabsorption nyob rau hauv proximal nephron tshwm sim thaum parathyrin nkag.
Ua kom muaj sodium reabsorption los ntawm cov tshuaj hormones:
- YVasopressin.
- YGlucogan.
- YCalcitonin.
- Aldosterone.
Kev txwv tsis pub sodium reabsorption tshwm sim thaum lub sijhawm tsim cov tshuaj hormones:
- YProstaglandin thiab prostaglandin E.
- Atriopeptide.
Lub paj hlwb cortex tswj cov kev tso tawm lossis inhibition ntawm cov zis.
Tubular reabsorption ntawm dej yog ua los ntawm ntau cov tshuaj hormones lub luag haujlwm rau permeability ntawm daim nyias nyias ntawm lub distal nephron, kev tswj ntawm nws txoj kev thauj mus los ntawm tubules, thiab ntau ntxiv.
Reabsorption nqi
Kev siv tswv yim ntawm kev paub txog kev paub txog dab tsi reabsorption yog - qhov no hauv cov tshuaj tau ua kom tau txais cov ntaub ntawv pov thawj ntawm kev ua haujlwm ntawm excretory system ntawm lub cev thiab saib rau hauv nws cov txheej txheem sab hauv. Kev tsim cov zis mus los ntawm cov txheej txheem nyuaj heev thiab kev cuam tshuam ntawm ib puag ncig, caj ces txawv txav ntawm nws. Thiab lawv tsis mus unnoticed thaum muaj teeb meem.tawm tsam lawv cov keeb kwm yav dhau. Hauv ib lo lus, kev noj qab haus huv tseem ceeb heev. Ua raws li nws thiab tag nrho cov txheej txheem tshwm sim hauv lub cev.
