Kwakhiwa Lapho isidoda is: kuphi futhi kanjani imfundo

Abesilisa akumele kube ngaphansi ukwazi kunabesifazane. Ngakho-ke, ezinye zazo zingabantu benesithakazelo emzimbeni yedivayisi siqu, futhi ikakhulukazi kwezitho zawo ezibalulekile kakhulu. Okugqamile kuleli cala kukhona odokotela, kanti bonke abanye nje enza izincwadi ukufunda okudingekayo. Imibuzo ezibaluleke kakhulu yilezi: Lapho kwakhiwa isidoda is? Wakwenza kanjani ibukeke? Zingaki izimpilo? Indlela yokuhamba? Ake sizame ukuyiphendula ngendlela ukuthi kucace kuwo wonke umuntu.

definition

Ngaphambi kokuba siphendule lo mbuzo, kubunjwa khona is isidoda, kumelwe lowo muntu baqonde ukuthi limelela. Isidoda - lokhu germ cells bezilwane nabantu. Ngokuvamile, la mangqamuzana ayakwazi ukuthuthela ngenkuthalo, okuyinto kubalulekile ukuze sifinyelele neqanda umquba.

Njengoba kuqhathaniswa insikazi germ cells, isidoda amaseli ezincane, emincanyana, futhi ngesikhathi esifanayo emzimbeni ukuvuthwa inani elikhulu (njengoba kuqhathaniswa iqanda, iyiphi umqhele amathathu zesifazane endocrine uhlelo).

Isakhiwo saleli cell lwegciwane lukhomba ukuthi zonke izilwane nesikhunta kwadingeka kukhokho oyedwa - ephilayo owumphumela. Ngokwesiko, iyiphi amaseli ubulili besilisa, ngisho izitshalo, ngokuthi isidoda, nakuba osebenzayo kubo futhi kwencazelo "isidoda" futhi anterozoidy.

Isidoda amaseli izilwane

Isimanga siwukuthi kodwa izilwane azihlukile kakhulu kusuka umuntu umbuzo isakhiwo kanye umsebenzi germ cells. Lapho akhiwa isidoda? Bawenza kanjani ukubheka? Ingabe kukhona ushintsho oluphawulekayo?

Jwayelekile isilwane isidoda has a ikhanda, i ingxenye Lesisemkhatsini kanye nomsila (noma umsila). Inhloko, ngokwesiko, kuyinto ikhenela, okuyinto ingxenye inani lezakhi zofuzo. Ngaphezu ulwazi zofuzo ekhanda babe enzyme ukwethulwa iqanda centriole. Lesisemkhatsini part entanyeni efanayo, kukhona mitochondrion ezinkulu, anikeza umzimba amandla futhi igcina msila yayo ukunyakaza.

Ukuxolela kusukela isampula Zimelela izinhlobo ngenhla ezithile zezinhlanzi aquarium kabani isidoda babe ezimbili flagella. Njengoba sihlobana ezinamagobolondo (bangase 'imisila "ezintathu noma ngaphezulu kusuka germ cells). Kodwa roundworms kwemvelo ekucasulayo amaseli motile - akukho cilia noma flagella emzimbeni wakhe. Ubulili amaseli kwalezi zilwane abe plastic cell udonga elikuvumela ukuzulazula usebenzisa prolegs. Ngo zintulo on isidoda fin samanje. Kodwa kunokwehluka hhayi kuphela imisila, kodwa futhi amakhanda. Uma umuntu bona ellipsopodobnye, kungcono amagundane kanye amagundane kungaba ozibongayo ifomu kryukopodobnoy.

Ubukhulu amaseli nekutala amadoda mancane kakhulu - kusuka amashumi emakhulwini micrometer. umehluko onjalo akuhlangene ne ubukhulu omdala.

Ukuvulwa kwesidoda

Ngaphambi ososayensi bezibuza umbuzo othi, "is isidoda ekhiqizwa kuphi?", Babengazi ukuthi ukuthi kukhona amaseli akhethekile ezihilelekile ukukhiqizwa zabantu nezilwane. Futhi ngokuvamile isakhiwo eziphilayo kwadingeka umqondo kancane kakhulu.

Revolution kwezesayensi ezenzeka esikhathini Maphakathi nekhulu lesikhombisa, lapho Antoine umDashi Leeuwenhoek yasungulwa microscope, wambuka izinto ezahlukene: impova, amacembe kanye amacembe of izitshalo, kwabantu nezilwane isikhumba nokuningi. Ngo 1677, ke beza germ cells. Wachaza iqanda nesidoda, okuyinto amchaza ngokuthi "isilwane isidoda."

Njenganoma yimuphi usosayensi, Leeuwenhoek kuqala zonke ukulinga ngokwakhe, kanjalo isidoda bokuqala ziye zachazwa, futhi kuphela ngemva kokuba nezinye izilwane. Umqondo wokuthi ngempela ngalezi "zilwane" zinengxenye ukukhulelwa, isinyathelo masinyane ikhanda Antoine sika, lapho yena uqobo engazange behluleka ukwazisa umphakathi British ngokwesayensi.

Kodwa lo mbono sinqatshiwe, futhi kubhekwe eminyakeni eyikhulu izimuncagazi isidoda emzimbeni womuntu, futhi akukho lutho okumelwe zalisa. Kuphela ekuqaleni kwekhulu nesishiyagalolunye, le Spallanzani Italian kwafakazela iqiniso lo mbono.

isakhiwo

Uma ungenalo acabangele ubude lo msila, isidoda yiseli encane kunazo zonke emzimbeni womuntu, cishe ngo-55 micrometer. Lezi Ubukhulu ezincane uyivumele ukuhambisa ngokushesha ngaphakathi komgodi kwesibeletho futhi ufinyelele iqanda.

Ukuze ibe kwetinhlavu isidoda, ebhekene uchungechunge kugucuka:
- nucleus iba ayazika ngu ukufingqa zofuzo;
- cytoplasm lihlukaniswa ehlukile "droplet cytoplasmic";
- kukhona kuphela labo organelles ezibalulekile iseli.

1. Inhloko iseli isidoda has ukuma i lesiyingi, a isicaba singatsheki. Ngezinye izikhathi kungaba ngilugweda ohlangothini olulodwa, bese sikwazi ukukhuluma ifomu ivame ukuba spoon. Esikhathini ikhanda yilezi:
   - core kokuba iqoqo haploid lezakhi zofuzo. Kuyadingeka ukuthi ngemva kokuhlangana lamaseli ezimbili ubulili isamba ukwaziswa kwezakhi zofuzo zazilingana ukuthi kwamaseli ukuphathwa kwabathintwayo, noma i-fetus ngeke basinde noma uyoba sengozini. Ngenxa "ukusikwa" enamandla chromatin ke alisebenzi futhi ayikwazi synthesize RNA.
   - acrosome - is evolutionarily Ushintshe Golgi apharathasi, kubalulekile ukuqinisekisa ukuthi inhloko yawo isidoda babekwazi ungene iqanda.
   - centrosome - organelle, olusekela le "cell skeleton" futhi inikeza ukuhamba umsila.
2. Phakathi ingxenye noma entanyeni - is olugcwele phakathi ikhanda nomsila. Kuyinto mitochondria, okuyinto ukukhiqiza amandla ngoba ukuhamba lo msila.
3. Tail noma umsila - ingxenye mncane ezithathekayo of isidoda. Enza ukujikeleza reciprocating ezinyakazayo, okuvumela iseli ukufinyelela umgomo.

umsebenzi

Indlela futhi spermatozoa indawo kumiswa ihlobene eduze nemisebenzi yayo. Futhi kubaluleke kakhulu kuzo - ukuthi Ukungena ku neqanda kokukhulelwa. Ukuze enze lo msebenzi, nemvelo uye walungiselela ukuhamba, mass futhi amakhemikhali "ukukhanga" kwesidoda.

eziphilayo Iduna nensikazi senzelwe kabusha zazo siqu, ngakho niyafanelana ngokwenyama, namanye amakhemikhali futhi zofuzo. Uma umuntu ethatha ukunakekelwa kwempilo yakhe, ayinakho imikhuba emibi, ngesikhathi ukwenza wonke imigomo (ikakhulukazi mumps), ama-germ cells yayo uzolunga ukwenza umsebenzi walo nganoma yisiphi isikhathi.

ezinyakazayo

isidoda kwetinhlavu amadoda kungenxa, phakathi kokunye, lapho kumiswa flagella, esiza amaseli ukuhambisa. Phakathi ukunyakaza gamete ijikeleziswa emhlabeni axis awo ngesivinini 0.1 amamilimitha angu ngomzuzwana. Kungaphezu amathathu amasentimitha ngehora. Badinga ukumboza ibanga 20 cm. Somewhere kwamahora ambalwa ngemuva kokuya ocansini, isidoda ukufinyelela amashubhu fallopian, futhi (uma kukhona amaqanda) kokukhulelwa kwenzeka.

Ngaphakathi lesidoda umzimba owesilisa cishe asibahambeli, awayona asebenzayo futhi zibukele wathutha eduze Amapayipi spermatic, kanye uketshezi kwesidoda ngenxa ukunyakaza peristaltic ka cilia futhi mapayipi.

Isikhathi sokuphila isidoda

Ososayensi kanye physiologists iye yazama ukubhekana nalo mbuzo lapho isidoda akhiwa futhi kungani ishintsha njalo? Kwavela ukuthi yonke inqubo nokuvuthwa of gametes kuthatha izinyanga ezingaphezu kuka ezimbili, kodwa ukuthola inani elikhulu. Ngenxa yalokho, amadoda kufanele Ziyintilibathwa zofuzo.

I ukusebenza isidoda lugcinwa kuphela ngenyanga, kanti zidinga izimo kwesokudla:
- izinga lokushisa ngenhla degrees 32 Celsius;
- ukungabi khona izifo ukuvuvukala.

Kodwa ngaphandle komzimba wesilisa, amaseli ukugcina ukuhamba kwabo kuze kube ngosuku. Ngaphakathi esibelethweni, kulokhu kungase kudluliselwe nakulabo izinsuku ezintathu.

Kuyini spermatogenesis?

Spermatogenesis - Ukwakheka kwezitho isidoda, okuyinto eyenzeka ngaphansi isiqondiso baqaphe wesistimu endocrine zomzimba.

Konke kuqala nge sikakhokho emangqamuzaneni okuthiwa ngemva kokuhlukana eziningana athathe isimo i isidoda omdala. Kuye kwatholakala izinhlobo ezingu-isidoda nokuvuthwa inqubo zingahluka. Ngokwesibonelo, e chordates ngesikhathi embryonic wabeka amaseli akhethekile ukuthi uthuthele ku-gonads futhi ifomu umklamo pool amaseli, kamuva abe spermatozoa.

Spermatogenesis human

Indlela tekwakha isidoda indoda akahlukile ukuthi ezinye ezilwaneni ezinomgogodla. Inqubo iqala ngesikhathi ukuthomba (engu-12) futhi usinika cishe iminyaka engaba ngu-80.

Ngokusho kwenye incwadi, isidoda nokuvuthwa umjikelezo ihlala izinsuku 64, ngakolunye - ukuze izinsuku 75. Kodwa ushintsho epithelium ijabulise (okuyinto substrate for the amaseli enzalo) akuyona ngaphansi kokukodwa ezinsukwini 16.

Yonke inqubo ithatha indawo convoluted tubules seminiferous we testis. Ngo ulwelwesi engaphansi tubules ahlelwe spermatogonia futhi spermatocytes ye-oda lokuqala nelesibili, lapho ke ukuhlukanisa esitokisini ovuthiwe. sikakhokho amaseli, uhambe kuqala yonke imijikelezo eziningana mitosis division, futhi uma they are ngokwanele, ukushintshela ku meiosis. Ngenxa yalokhu division zokugcina ukhiqiza spermatocytes ezimbili indodakazi, bese omunye spermatids ezimbili. Ngayinye yalezi amaseli has nengxenye inani lezakhi zofuzo futhi kungaba zalisa iqanda.