Ovogenesis - yinqubo kumiswa amaqanda. Spermatogenesis futhi oogenesis

Noma yimuphi ukuphindaphindeka noma ukukhiqizwa kabusha wenzalo ezweni - lokhu ingenye umsebenzi obaluleke kunayo yonke imiphefumulo ephilayo ehambahambayo, eplanethini yethu. Izinhlayiya eziyisisekelo zofuzo lidluliselwa abazali enzalweni, okwenza kube Adalberto isikhathi eside ukuba ziphazamise uhlanga lwakhe. Namuhla sikhuluma kabanzi mayelana nokuzala womuntu. Cabanga njengezinto ezifana spermatogenesis futhi oogenesis. Lapho inqubo zizalela luqala nini? Yiqiniso, nge Ukungena kwamaseli besilisa ku zesifazane. abazange Nivelaphi? Sinesithakazelo inqubo gametogenesis. Ovogenesis - kuyinqubo ezilandelanayo lemfundo kwamaseli zesifazane zokuzala. Spermatogenesis - ukwakheka wesilisa ocansini cell. Sizokwenza ukubhekana namuhla, yini ukufana, nomahluko kilelihlelo.

iqanda

Sishilo kakade ukuthi ovogenesis - yinqubo kabusha amaseli zesifazane yenzalo, ubizwa ngokuthi "iqanda." Sinikeza ukukhuluma kancane ngalokho kungenxa nalokho umsebenzi wenziwa. Ukuhlola kafushane isakhiwo iqanda.

Njengoba kushiwo ngaphambili, iqanda - yeseli ubulili, okuyinto has simise oyindilinga. Kufanele aqukethe wonke umsoco ezidingekayo, ngoba umsebenzi wayo oyinhloko Ukuqinisekisa ukuthuthukiswa i umzimba kusuka ngesikhathi sokukhulelwa. Njenganoma iyiphi enye cell, iqanda maphakathi iqukethe i-nucleus. Emhlabeni core neqoqo haploid wama-chromosomes kuyinto cytoplasm. Y kuyinto iqanda isendlalelo engenhla zokuzivikela - umqhele akhishwa imisebe yalo. Leli gama, lesi igobolondo kwakubangelwa yokuthi liqukethe inqwaba villi encane.

Eduze kwakheka core is ngenxa meiosis komunye umzimba encane, kuba kumiswa amancane kakhulu Usayizi cell. Kuzo zonke, intombazane kuzalwa isitoko kukhona ayisigidi amaqanda. Kodwa ngokuhamba kwesikhathi, abaningi babo bayafa. Kuze okwamanje zokuthomba, kunezinguqulo ezingaba ngu-300 eziyinkulungwane kuphela, kanye nge-ovulation amayelana 400 babo. Yini isibe okunye? Bamane afe, futhi anginaso isikhathi ukuze uvuthwe.

Siphakamisa ukuxoxa inqubo ebizwa ngokuthi "oogenesis". Lona nokuvuthwa we gametes besifazane kakhulu. Asiqale manje.

ovogenesis

Ovogenesis - Ukwakheka kwezitho gametes zesifazane. Ngokushesha kufanele licaciswe ukuthi ezincelisayo, uqala esesesiswini ezweni, okungukuthi e utero. Ngaphambi kokuthi enumerate futhi agcwele zonke izigaba oogenesis, ukukhomba injongo eyinhloko yale nqubo. Ngakho, umsebenzi:

• Kuyi-nucleus iqanda kufanele abunjwe isethi haploid wama-chromosomes;
• ukwaneliseka zygote ebukhoneni izakhamzimba.

Can ngokushesha uqaphele ukuthi inqubo ovogenesis akuyona okuningi ezahlukene kusukela spermatogenesis, uzophawula kuwo.

Ngakho ovogenesis esiteji yilezi ezilandelayo:

• nokubeletha;
• ukukhula;
• nokuvuthwa.

Isigaba sokuqala senzeka esibelethweni. Le ntombazane has kakade inombolo enkulu primordial germ cells, okuyinto kulesigaba yilezi: umklamo noma imibungu. Lezi amaqanda esizayo kakhulu ngenkuthalo sokuhlukanisa, ngakho kukhona ukunqwabelana oogonia. Zinqwabelanisa ungqimba cortical. It oogonia buthelela zonke izakhamzimba ezidingekayo, okuyilezi:

• amaprotheni;
• amafutha;
• glucose.

Uyini umehluko phakathi oogonia kusukela germ cells? Ziyakwazi emikhulu ngosayizi. yokufana kwawo itholakala lokuthi ukuthi zofuzo ezifanayo.

Khulumela kafushane esigabeni sesibili, sizobona ukuthi kwenzekani futhi ukuzalwa intombazane. Manje kusukela oogonia kwakhiwa oocytes ye-oda kuqala. Usayizi kwalesi sigaba kakhulu ziyancipha, kodwa oocytes ngokushesha ukuthola isisindo sabo. Ngaphezu kwalokho egg esizayo has a ukulondolozwa eside ngesimo oocytes prophase. Manje kukhona abangaba yizigidi ezimbili, futhi ngeke athuthukiswe 400 kuphela oocytes.

Isigaba sokugcina kwenzeka ngemva semali isikhathi (mayelana 11-12 iminyaka, futhi ngezinye izikhathi ezingaphezu). Kulesi sigaba, ngokungazelelwe iqala ukuthuthukiswa wayo ingenye oocytes balondolozwa. Umphumela kuyofika nyangazonke.

isidoda

Safunda ukuthi oogenesis kwakhiwa besifazane ocansini cell esibizwa esibelethweni. Manje ukuya spermatogenesis futhi germ cells besilisa. Ngakho, njengoba liqhubeka isintu esidinga yebhangqa iqanda, elikwaziyo umquba. Isidoda - lena ingxenye eyodwa ezidingekayo.

Esikhathini wesilisa, isidoda kungaba izigidi eziningi, njengoba kuqhathaniswa iqanda emzimbeni yabesifazane. Zakha:

• kusukela ekhanda;
• intamo;
• phakathi;
• umsila filamentous.

Lapho isidoda ukufinyelela iqanda, umsila, kwesokudla ukuhambisa, siqedwa. Khona-ke owesifazane germ cells okuhambisa kuphela inhloko isidoda, kusukela athwala izinhlayiya eziyisisekelo zofuzo. It is ukuthi igobolondo amaqanda sinamandla ngempela okwaziwayo, ngakho inhloko yabangamashumi acrosome isidoda lapho. Iqukethe into ekhethekile, okuyinto yakwazi ukuncibilikisa ulwelwesi. Usayizi iseli zomuntu zokuzala kuyinto amamilimitha angu-0.05 kuphela, ngakho ukuze ngisibone, udinga ngesibonakhulu esinamandla.

spermatogenesis

Spermatogenesis futhi oogenesis - kungcono izinqubo kuhle efanayo. Izinyathelo zokuqala yilezi ezilandelayo:

• nokubeletha;
• ukukhula;
• nokuvuthwa;
• kumiswa.

In the isinyathelo ukukhiqizwa kabusha Kumiswa kwenkulungwane spermatogonia sokuhlukanisa ngamunye izikhathi ezingaba yishumi. Phakathi division bona zikwazi ukuthola izakhi.

Phakathi ukukhula yini ukwandisa ngobukhulu kakhulu. Kuyinto ushintsho isigaba sokukhula kwenzeka spermatogonia spermatocytes oda kuqala.

Ngo isinyathelo 2 ukuqoqwa nokuvuthwa kwenzeka:

• meiosis (ngenxa esinalo spermatocytes oda 2nd);
• mitosis (kwakhiwa spermatids).

Phakathi kumiswa spermatids mbeni izinqubo cell, futhi isidoda kwakhiwa. Lapho beqeda kumiswa zabo, ukuhamba inzuzo.

ukufana

Kufanele ngokushesha kuqashelwe lokuqala ukufana oogenesis futhi spermatogenesis - kokubili izinqubo ezidingekayo ukuze ukwakheka, ukukhula kanye nokuvuthwa we gametes, noma iduna noma insikazi. Nakuba enqubeni kukhona izinto eziningi ezifanayo, kodwa umuntu angakwazi ukuhlonza umehluko othize.

Esinye isici ovamile uwukuthi izigaba kucishe yenqubo (e spermatogenesis ngesinye isikhathi ngaphezulu). Izinyathelo jikelele:

• nokubeletha;
• ukukhula;
• nokuvuthwa.

Izici lezi izigaba, sixoxe ngokuningiliziwe ngenhla. Thina uqhubekele umehluko.

umehluko

Ake uqale nge yokuthi sinawo Imiphumela ezahlukene oogenesis futhi spermatogenesis, oogenesis oluhambisana nesimo esinjalo, njengoba kumiswa insikazi amaseli enzalo kanye spermatogenesis - besilisa. Njengoba uke waphawula kakade, kule nqubo ye kumiswa spermatozoa ngesinye isikhathi ezingaphezu kuka ukwakheka iqanda. Eyokuqala nazo ukwakheka esiteji, kuyilapho oogenesis kule isinyathelo ayidingeki.

inqubo ovogenesis iqala amantombazane esibelethweni, futhi spermatogenesis iqala labafana batholile engu-12 ubudala. Lona omunye umehluko.

Umehluko lokugcina isibalo esikhulu germ cells wesilisa njengoba kuqhathaniswa abesifazane. Lokhu kungachazwa kanje: iqanda zuza one kuphela isidoda iseli abangaba yizigidi ezingu-200.