"Ilizwe kufuneka likwazi amaqhawe alo!" - esi siqendu singasetyenziselwa ukubiza ulwazi oluthe xaxa malunga ne "bait", leyo, ngokwembono eninzi, ithatha inxaxheba kwinkqubo yokuchumisa nokuzalwa kobomi obutsha. Emva koko, bona, i-spermatozoa, ngamaqhawe ngokwenene. Umkhosi wabo we-multimillion ulungele ukufa ukuze uhlangane nenjongo yesojoni elinye kuphela - intlanganiso efanelekileyo kunye neqanda ...
I-Spermatozoon yincinci yegciwane lesigqirha lesigqirha (i-gamete) eselunxwemeni esakhiwe kwiitules ezixubileyo zentlanzi kunye nobude obude be-50-60 microns, umsebenzi oyintloko wokuba uvelise izinto eziphathekayo zofuzo kwiqanda ngokulwa nephepha lomzimba wesini. Ukuzaliseka kwale mishini kunokwenzeka kuphela ngenxa yesakhiwo esithile esiyinkimbinkimbi yesityalo.
Njengoko kuboniswa ngumzobo wesakhiwo se-spermatozoon kwisalathisi esingezantsi, nangona umahluko ovela kwezinye iiseli zomzimba, isakhiwo se-spermatozoon sabantu sichaphazeleka kwaye sibandakanya izakhiwo zeselula njengentloko, intamo, umzimba kunye nomsila (flagellum).
Intloko yesininzi yesilisa, iqukethe i-nucleus encinci ye-haploid ene-23 yama-chromosomes, apho emva kokudibanisa neqanda, ukwakha i-zygote, iba ngumzimba we-diploid kunye nama-chromosomes omama kunye noyise emva kokuthelekiswa namanye amaseli.
Ngaphantsi kwekhondom ye-plasma phambi kwentloko, ihlanganisa isiqingatha se-nucleus ngendlela ye "cap", i-acrosome yesidoda ifakwa. Iqulethe i-enzyme ye-acrozine, leyo, ekudibanisaneni neqanda, iyakwazi ukuyidiliza igobolondo yayo kwaye ivumele ukuba isidoda singene ngaphandle kobunzima. Kwaye ngokuchumisa kweqanda, kuphela intloko kunye nenucleus yesisu evela kwisixhobo sokuzalwa esihlala kuyo, zonke izitho zeselfowuni zihlala ngaphandle.
Icandelo eliphakathi le spermatozoon limelelwe entanyeni nasemzimbeni, emva kwayo imsila - ilungu lokuhamba kwendoda ye-gamete. I-mitochondria ye-Spirit yecandelo eliphakathi lifaka i-cytoskeleton ye-flagellum evela kwi-microtubules kwaye ixanduva lwamandla afanelekileyo ukuba inyuke inyoka. Isantya sokunyakaza kwesidoda sifikelela kuma-microns ama-50 ngesibini okanye ukuya kwi-1.5 cm ngomzuzu. Olunye uhlobo lwamafutha kulolu hlobo luyi-fructose, equlethwe kwisidoda.
Iintlobo ze-spermatozoa kunye nesondo lomntwana ongakazalwa
Kukho iintlobo ezimbini zesidoda esichaphazela ngesondo lomntwana: i-spermatozoa ene-X-chromosome-gynospermia, xa idibanisa neqanda, intombazana izalwa, kunye ne-spermatozoa ene-Y-chromosome - androspermia, ejongene nokuzalwa kwenkwenkwana. Kuye kwabonakaliswa ngokwesayensi ukuba sele sele ikhulelwe ingqalelo ukuba inokukwazi ukucacisa ngezinga eliphezulu lokulala ngesondo elizayo lomntwana. Ngako-ke, ngaphezulu kweselula, kodwa ube nexesha elifutshane lempilo ye-androspermia ngeli xesha le-ovulation ngokukhawuleza kunendlela ye-X-spermatozoa i-ovum, eyenza ukuba umkwenkwe umfana ufumaneke. Ngaloo ndlela, ukukhulelwa kwentombazana kuya kwenzeka xa kunesiphelo sokungena kwintsholongwane yomjikelezo wokuya esikhathini, ekubeni i-gynospermia encinci ye-mobile inexesha elide lokuphila.
Inqanaba lokukhula kwentsuku ye-spermatozoa ifinyelela ukuba bachitha ii-2.5 kwiinyanga kunye nehafu yesenyanga kwiintetho.
