Apho yenzala abunjwe: indlela nalapho imfundo

Akayi kuvalwa, ukuze ungabi ngaphantsi ukwazi kuneentombi. Ngoko ke, ezinye zazo abanomdla kakhulu emzimbeni isixhobo kaThixo, kwaye ingakumbi amalungu ayo ibalulekileyo. Bold kulo mzekelo kukho oogqirha, kwaye abanye wenza nje uncwadi yokufunda efunekayo. Le mibuzo ibalulekileyo zezi: Apho isidoda yakheke? Njani ukufana? Zingaphi ubomi? ihamba njani? Masizame ukuyiphendula ngendlela yokuba kucacile ukuba wonke.

definition

Ngaphambi kokuba siphendule lo mbuzo, ezikhandelwa apho isidoda, umntu umele aqonde ukuba umele. Isidoda - le intsholongwane iiseli kwezilwanyana nabantu. Ngokuqhelekileyo, ezi seli bayakwazi ukuya ngamandla, nto leyo kubalulekile ukuze kufikelelwe iqanda ndigalele umgquba.

Njengoko kuthelekiswa iiseli yintsholongwane nemazi, iiseli inqubo ezincinane, nimble, kwaye ngexesha elinye emzimbeni ekhulisa inani elikhulu (ngokuchasiweyo iqanda, nguwuphi na isithsaba amathathu inkqubo yonyango obhinqileyo).

Ubume kule seli intsholongwane lubonisa ukuba zonke izilwanyana kunye fungi waba kumntu omnye - i kokuphilayo kweseli enye. Ngokwemveli, naziphi na iiseli zesini eyindoda, nkqu izityalo, ekuthiwa isidoda, nangona esebenzayo kubo kunye nenkcazo "sperm" kunye anterozoidy.

amadlozi izilwanyana

Isimanga, kodwa hayi izilwanyana ezahlukeneyo kakhulu ukusuka umntu umbuzo ngesakhiwo umsebenzi kweeseli lwegciwane. Apho isidoda kwakheka? zikhangeleka njani na? Ingaba kukho naluphi na utshintsho isisiseko?

Normal isidoda isilwanyana intloko, isahlulo eliphakathi kunye nomsila (okanye yomsila). Intloko, ngokwemveli, na kernel, leyo kwesiqingatha senani zofuzo. Ukongeza iinkcukacha yemfuza intloko babe enzayim ukulungiselela ukuqaliswa kwe iqanda kunye centriole. Inxalenye esiPhakathi limi entanyeni enye, kukho mitochondrion enkulu, enika amandla kwaye ugcina intshukumo yayo yomsila.

Ukuxolelwa kwisampula zimelwe iintlobo ngentla ezithile zeentlanzi akwariyam amadlozi kabani na misila ezimbini. Njengoko inxulumene intlanzi (ukuze babe "nemisila" ezintathu okanye ngaphezulu iiseli intsholongwane). Kodwa ziintshulube kwemvelo ucatshukiswe iiseli motile - akukho isiliya okanye misila emzimbeni wakhe. iiseli Sex yezi zilwanyana kuba iseli udonga yeplastiki ekuvumela ukuba indlela ngokusebenzisa prolegs. Xa leenewt on isidoda fin ngoku. Kodwa akukho kwahluka hayi kuphela imisila, kodwa kwiintloko. Ukuba umntu ellipsopodobnye, ukuba iimpuku kunye neempuku nga ifomu kryukopodobnoy ndiqhayise.

Imilinganiselo okuzala ebantwini ezincinane kakhulu - ukusuka amashumi amakhulu micrometers. umahluko enjalo akunanto yakwenza kubungakanani abadala.

Ukuvulwa madlozi

Ngaphambi kokuba izazinzulu baye bazibuza lo mbuzo: "Liphi na sperm wavelisa phi?", Wayengazi ukuba kukho iiseli ezikhethekileyo ababandakanyekayo lokwanda abantu kunye nezilwanyana. Kwaye ngokubanzi ubume eziphilayo wayengazi kakhulu.

Revolution zesayensi kwenzeka phakathi kwinkulungwane elinesixhenxe, xa Antoine umDatshi Leeuwenhoek wasungula neemicroscope wajonga kuye izinto ezahlukeneyo: umungu, amagqabi kunye ezinamagqabi zezityalo, isikhumba abantu kunye nezilwanyana kunye nangaphezulu. Ngowe-1677, it up weza lwegciwane iiseli. Wachaza iqanda kunye amadlozi, apho uchazwa ngokuba "isilwanyana ZakwaLizwi Zehlabathi."

Njengaye nawuphi Scientist, Leeuwenhoek kuqala ukubeka onke amalinge phezu ngokwakhe, ngokunjalo yobudoda sokuqala sele ichaziwe, yaye kuphela emva kokuba ezinye izilwanyana. Ingcamango yokuba le "zilwanyana" aqukiweyo ukukhulelwa, ngokukhawuleza kufika entlokweni Antoine, nto leyo zange ajike ukwazisa uluntu lwezenzululwazi yaseBritani.

Kodwa enqaba lo mbono, yaye iminyaka elikhulu kucingwe izinambuzane amadlozi emzimbeni womntu, okanye bengenanto umgquba. Kuphela benkulungwane yeshumi elinesithoba, i-Italian Spallanzani kwaba yinyaniso le ngcamango.

isakhiwo

Ukuba ngaba uthathe ingqalelo ubude yomsila, isidoda seli incinane emzimbeni womntu, malunga 55 micrometers. Le milinganiselo ezincinane ukuvumela ukuba ukuhamba ngokukhawuleza em- isibeleko nokufikelela eqandeni.

Ukuze ibe ngaphantsi nkqu ukuyilwa madlozi, ukuba bangenele uthotho zinguquko:
- isiqalo uba zamahlathi ngakumbi amafu impahla yofuzo;
- kukho icytoplasm wahlukene ibe "kwamathana cytoplasmic" ezahlukeneyo;
- kukho kuphela ezo organelles ukuba zibalulekile kwi iseli.

1. Intloko iseli isidoda imilo an ellipse, a atshabalalisa yokuxazulula. Ngamanye amaxesha kuba phakathi kwelinye icala, uze ke sithethe ifomu kuyaphela naan. Xa zibaliwe:
   - okuyiyo kokuba iseti haploid zofuzo. Kuyimfuneko ukuba emva ngokudibana iiseli ezimbini sex imali iyonke ulwazi yemfuza wayelingana ukuba iiseli somatic, okanye umbungu abayi kusinda okanye uzakuba sengozini. Ngenxa "ucutheko 'olomeleleyo chromatin luyeke kwaye akakwazi nokulungelelanisa RNA.
   - acrosome - ke evolutionarily modified izixhobo Golgi, kubalulekile ukuqinisekisa ukuba intloko yobudoda babekwazi ungene eqandeni.
   - centrosome - organelle, nto leyo exhasa i "iseli skeleton" kwaye inika intshukumo nomsila.
2. Indawo ephakathi okanye entanyeni - into ukuvala phakathi intloko nomsila. Yeyona mitochondria, ekuthi kwezo nto kuphume amandla ngenxa intshukumo yomsila.
3. Ngomsila okanye umsila - inxalenye obhityileyo ezihambisekayo ye yobudoda. Wenza Buyisela motion rotation, esivumela iseli ukufikelela usukelo.

umsebenzi

Le ndlela kunye spermatozoa ndawo Ukwakheka ngokusondeleyo ezinxulumene nemisebenzi yayo. Kwaye ke kubaluleke gqitha kubo - loo nto ukungena kwi iqanda isichumiso. Ukuze wenze lo msebenzi, indalo ulungiselele ukushukumiseka, ubunzima kunye yamachiza "nomtsalane" madlozi.

eziphilayo indoda nenkazana eyenzelwe lokwanda ngohlobo lwazo, ngoko ke ehambelanayo emzimbeni, iikhemikhali kunye zemfuza. Indoda esukuba izeka ukunyamekela impilo yakhe, Akukho imikhwa emibi, ngexesha ukwenza zonke ugonyo (ingakumbi uqilikwane), iiseli zawo ntsholongwane iya kuba ukulungele ukwenza umsebenzi wayo nangaliphi na ixesha.

motion

isidoda uluhlu babantu kubangelwa, phakathi kwezinye izinto, kunye nokusekwa misila, nto leyo inceda iiseli ukuhamba. Ngexesha ukuhanjiswa gamete esijikeleziswa ngeenxa axis yayo ngesantya ka 0.1 eemilimitha ngomzuzu. Kuyinto iisentimitha ngaphezu amathathu ngeyure. Kufuneka yokuzunguleza umgama-20 cm. Ndaweni ithile emva kweeyure ezingengaphi emva neentlobano zesini, isidoda zifike tubes, kwaye (ukuba kukho iqanda) kokukhulelwa kwenzeka.

Ngaphakathi isidoda komzimba inkunzi phantse abangeni, bengengabo iyasebenza kwaye basonge bafudukela ecaleni imibhobho spermatic, kunye ulwelo ZakwaLizwi ngenxa kwiintshukumo peristaltic of isiliya kunye imibhobho.

Siphila madlozi yobomi

Izazinzulu kunye physiologists baye bazama ukujongana nomba apho isidoda akhiwa futhi kutheni zihlaziywa rhoqo? Ndafumanisa ukuba yonke inkqubo ekukhuleni gametes kuthatha ngaphezu kweenyanga ezimbini, kodwa ufumana inani elikhulu. Ngenxa yoko, amadoda akukho yokunqongophala genetic material.

Ugqitho lwe yenzala igcinwe kuphela inyanga, ngoxa kufuneka iimeko ekunene:
- lobushushu ngaphezu kweqondo 32 Celsius;
- nokungabikho kwezifo arhabaxa.

Kodwa ngaphandle komzimba inkunzi, iiseli ukugcina ukuhamba yawo ukuya ngemini. Ngaphakathi isibeleko, eli xesha kuthi uyinikwe iintsuku ezintathu.

Yintoni spermatogenesis?

Spermatogenesis - Ukwakheka madlozi, leyo eyenzeka phantsi ummiselo elibukhali inkqubo yonyango lomzimba.

Yonke lento iqala ngo iiseli ukhokho, emva iyantlukwano eziliqela athathe emilise sperm abadala. Kuxhomekeka kuhlobo zenkqubo nokwanda sperm ungahluka. Ngokomzekelo, xa chordates ngexesha osandul wabeka iiseli ezikhethekileyo abeza kweli gonads kunye nefomu primordia lidike iiseli, nto leyo koko babe spermatozoa.

Spermatogenesis yabantu

Indlela ngokwenza yobudoda umntu ayahlukanga kuleyo kwezinye ekuyo. Le nkqubo iqala xa ufikisa (ubudala-12) yaye ubonakalisa phantse ukuya kwiminyaka engama-80.

Ngokutsho kwenye incwadi, umjikelo amadlozi nokwanda ihlala iintsuku 64, kwelinye - iintsuku 75. Kodwa utshintsho epithelium tubular (nto leyo zeendawana ukuba iiseli okuzala) ayikho ngaphantsi kwe kanye ngeentsuku ezili-16.

yonke le nkqubo ithabatha indawo tubules kwalula seminiferous wetyhalarha. Kwigumbi elingaphantsi inwebu of tubules amalungiselelo spermatogonia kunye spermatocytes yomyalelo lokuqala nolo lukwizinga lesibini, ngoko umahluko kwiseli oqolileyo. iiseli yokuqala ukhokho iphumele imijikelo eziliqela sisahlula mitosis, kwaye xa ngokwaneleyo, ushintshele meiosis. Ngenxa yeli candelo lokugqibela uvelisa spermatocytes ezimbini intombi, waza ke omnye spermatids ezimbini. Nganye kwezi seli ingxenye inani zofuzo kwaye umgquba iqanda.