Spermatogenesis: kuyini nokuthi zenzeka kanjani izigaba eziyinhloko

-Delile

• Izigaba eziyinhloko ze-spermatogenesis
• 1. Isigaba sokuhluma
• 2. Isigaba sokukhula
• 3. Isigaba sokuvuthwa
• 4. Isigaba sokwehlukanisa
• Ilawulwa kanjani i-spermatogenesis

I-Spermatogenesis ihambelana nenqubo yokwakha isidoda, okuyizakhiwo zesilisa ezibhekele ukukhulelwa kweqanda. Le nqubo imvamisa iqala eminyakeni yobudala eyi-13, iqhutshwe impilo yonke yendoda futhi inciphe ekugugeni.

I-Spermatogenesis inqubo elawulwa kakhulu ngamahomoni, njenge-testosterone, i-luteinizing hormone (LH) ne-follicle stimulating hormone (FSH). Le nqubo yenzeka nsuku zonke, ikhiqiza izinkulungwane zesidoda nsuku zonke, ezigcinwa ku-epididymis ngemuva kokukhiqizwa kwayo kumasende.

Izigaba eziyinhloko ze-spermatogenesis

I-Spermatogenesis inqubo eyinkimbinkimbi ehlala phakathi kwezinsuku ezingama-60 nezingama-80 futhi ingahlukaniswa ngokwezinyathelo ezimbalwa:

1. Isigaba sokuhluma

Isigaba sokuhluma yisigaba sokuqala se-spermatogenesis futhi senzeka lapho amangqamuzana egciwane esikhathi sombungu aya emasendeni, lapho ahlala engasebenzi futhi engavuthiwe, futhi abizwa ngokuthi ama-spermatogonias.

Lapho umfana efinyelela ebusheni, isidoda, ngaphansi kwethonya lamahomoni namaseli we-Sertoli, angaphakathi kwamasende, athuthuka kakhulu ngokuhlukaniswa kwamaseli (mitosis) futhi akhiphe ama-spermatocyte ayinhloko.

2. Isigaba sokukhula

Ama-spermatocyte ayinhloko akhiwa esigabeni sokuhluma akhula ngosayizi futhi aqhubeke nenqubo ye-meiosis, ukuze izinto zazo zofuzo ziphindwe kabili, zaziwe njengama-spermatocyte wesibili.

3. Isigaba sokuvuthwa

Ngemuva kokwakhiwa kwe-spermatocyte yesibili, inqubo yokuvuthwa yenzeka ukukhulisa isidoda ngokuhlukaniswa kwe-meiotic.

4. Isigaba sokwehlukanisa

Ihambisana nesikhathi sokuguqulwa kwesidoda sibe isidoda, esihlala cishe izinsuku ezingama-21. Ngesikhathi sesigaba sokuhlukanisa, esingabizwa nangokuthi i-spermiogenesis, kwakhiwa izakhiwo ezimbili ezibalulekile:

• I-Acrosome: kuyisakhiwo esikhona ekhanda lesidoda esiqukethe ama-enzyme amaningana futhi avumela isidoda ukuba singene eqandeni lowesifazane;
• Isishayo: isakhiwo esivumela ukuhamba kwesidoda.

Yize ine-flagellum, isidoda esakhiwe asinayo i-motility kuze kube yilapho seqa i-epididymis, sithola amandla we-motility namandla okukhulelwa phakathi kwamahora ayi-18 nama-24.

Ilawulwa kanjani i-spermatogenesis

I-Spermatogenesis ilawulwa ngamahomoni amaningana angagcini ngokuthanda ukuthuthukiswa kwezitho zobulili zesilisa, kepha futhi nokukhiqizwa kwesidoda. Enye yamahomoni amakhulu yi-testosterone, eyi-hormone ekhiqizwa amaseli eLeydig, angamaseli akhona kuma-testis.

Ngaphezu kwe-testosterone, i-luteinizing hormone (LH) ne-follicle stimulating hormone (FSH) nayo ibaluleke kakhulu ekukhiqizeni isidoda, njengoba ivuselela amaseli eLeydig ukuthi akhiqize amangqamuzana e-testosterone ne-Sertoli, ukuze kube nokuguqulwa kwesidoda ku-spermatozoa.

Qonda ukuthi ukulawulwa kwamahomoni kohlelo lokuzala lwabesilisa kusebenza kanjani.