Umthondo

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A umthondo (penises ubuningi noma penes /-n i z / ) kuyinto eyinhloko isitho sobulili ukuthi owesilisa izilwane zisebenzisa ukuba omunye nabesifazane (noma hermaphrodites ) ngesikhathi copulation.Izitho ezinjalo zenzeka ezilwaneni eziningi, ezinomgogodla nezingenamgogodla, kepha abesilisa abawuthwali umthondo kuzo zonke izinhlobo zezilwane, futhi kulezo zinhlobo lapho owesilisa ethwala khona okubizwa ngokuthi yipipi, imithondo ezinhlotsheni ezahlukahlukene ngempela i- homologous .

Igama elithi ipipi lisebenza ezithweni eziningi ezingenayo, kepha hhayi kubo bonke.Njengesibonelo, isitho esingena ngaphakathi se- cephalopoda esiningi yi- hectocotylus, ingalo ekhethekile, nezicabucabu zesilisa zisebenzisa izinyawo zazo.Ngisho ngaphakathi kweVertebrata kunezinhlobonhlobo ze-morphological ezinamagama athile, njenge- hemipenes .

Ezinhlotsheni eziningi zezilwane lapho kukhona isitho esingahle sichazwe njengepipi, asinomsebenzi omkhulu ngaphandle kokungenelela ngaphakathi, noma okungenani sidlulisela isidoda kowesifazane, kepha ezilwaneni ezincelisayo ezingamaphosta ipipi lithwala ingxenye ekude kwe- urethra, ekhipha womchamo womabili ngesikhathi sokuchama kanye nesidoda ngesikhathi sokuhlangana.

 

Ama-Vertebrates[hlela | Hlela umthombo]

UMallard mbumbulu-umthondo

Iningi lezinyoni zesilisa (isb., Amaqhude nama- turkeys ) zine- cloaca (nayo ikhona kowesifazane), kodwa hhayi ipipi. Phakathi kwezinhlobo zezinyoni ezinepipi kukhona ama-paleognathes ( tinamous and ratites ) ne- Anatidae (amadada, amahansi nama-swans).Umthondo wezinyoni uhlukile ngesakhiwo kusuka ekunciphiseni kwesilwane esincelisayo, ekubeni ukunwetshwa kwe-erectile kodonga lwe-cloacal nokwakhiwa yi- lymph, hhayi igazi.Imvamisa inezimpaphe eziyingxenye kanti kwezinye izinhlobo inezinhlobonhlobo zemicu kanye nemicu efana nebhulashi, nasesimweni esibucayi sigoba ngaphakathi kwe- cloaca.Idada echibini (elibizwa nangokuthi i-Argentine blue-bill) linomthondo omkhulu kunayo yonke maqondana nosayizi womzimba wawo wonke ama-vertebrate; ngenkathi imvamisa icishe ibe uhhafu wosayizi womzimba (20 cm), isifanekiso esinepipi 42.5 cm ubude bubhaliwe.

Abesifazane banezikulufu zokuvala ukhokho ezinamaphakethe amaningi angaboniyo enzelwe ukungena okunzima nokuvikela ukukhulelwa. Lokhu kwehlise amathuba okukhuleliswa ngabahlaseli abangadingeki bavuna abalingani abafanele.

Idada ledamu liyaziwa ngokuba nalo, maqondana nobude bomzimba, umthondo omude kunawo wonke ama-vertebrate ; ipenisi, evame ukugoqelwa esimweni se-flaccid, ingafinyelela cishe ebangeni elilinganayo nesilwane uqobo lapho imile ngokuphelele, kepha imvamisa cishe cishe isigamu sobude benyoni. [1] [2]Kucatshangwa ukuthi ubukhulu obumangalisayo bezitho zabo zomlomo ezinamathiphu anezinwele kungenzeka ukuthi zavela ngenxa yengcindezi yokuncintisana kulezi zinyoni ezinokuziphatha okubi kakhulu, kwasusa isidoda ekuhlanganisweni kwangaphambilini ngendlela yokuxubha ibhodlela.Idada ledamu linomthondo obunjwe ngesikebhe.

Ama- emus wesilisa nowesifazane ayafana ngokubukeka, [3] yize isitho sowesilisa singabonakala lapho sizithuma. [4]

I-tinamou yesilisa inepipi elibunjiwe ngokhokho, elifana nelama-ratites kanye ne- hemipenis yezinye izilwane ezihuquzelayo.Abesifazane banesitho esincane sobudoda ku-cloaca esiba sikhulu ngesikhathi sokuzala. [5]

Izilwane ezincelisayo[hlela | Hlela umthombo]

Izitho zobulili zesilisa zangaphandle zeLabrador Retriever

Njenganoma iyiphi enye imfanelo yomzimba, ubude nobubanzi bomthondo bungahluka kakhulu phakathi kwezilwane ezincelisayo zezinhlobo ezahlukene.Ezilwaneni eziningi ezincelisayo, usayizi wepenisi oyiflaccid mncane kunosayizi omile .

Ithambo elibizwa ngokuthi i- baculum noma i- os penis likhona ezilwaneni eziningi ezincelisayo kepha alikho kubantu, ezinkomeni nasemahhashini .

Ezilwaneni ezincelisayo umthondo uhlukaniswe izingxenye ezintathu:

  • Izimpande (i- crura ): lezi ziqala emngceleni we- caudal we-pelvic ischial arch .
  • Umzimba : ingxenye yesitho sowesilisa esukela ezimpandeni.
  • Glans : ukuphela kwamahhala komthondo.
Abantu[hlela | Hlela umthombo]

 

Umthondo womuntu, kususwe izinwele zasesidlangalaleni ukukhombisa imininingwane yokwakheka

I umthondo womuntu kuyinto lesitho sobulili somuntu sangaphandle besilisa abantu.Kuyisitho sokuzala, esingenakuqhamuka futhi esisebenza njengomsele wokuchama . Izingxenye eziyinhloko ziyimpande yepenisi (i-radix): Yingxenye enamathiselwe, equkethe isibani sepenisi phakathi nendawo ne- crus yepipi, eyodwa ngapha nangapha kwe-bulb; umzimba womthondo (corpus); kanti i- epithelium yomthondo iqukethe isikhumba s shaft, ijwabu, nomucu ongaphambi kokungaphakathi ngaphakathi kwejwabu bese umboza umthondo we-glans.

Umthondo womuntu wakhiwe ngamakholomu amathathu ezicubu : ama- corpora cavernosa amabili alala eceleni komunye ohlangothini lwenqolobane kanti enye ye- corpus spongiosum ilele phakathi kwabo ohlangothini lwe-ventral .I urethra, okuyinto ingxenye lokugcina ngomgudu womchamo, unqamula lo spongiosum Corpus, futhi wokuvula yayo, eyaziwa ngokuthi i- meatus /m i eɪ t ə s /, amanga ku ichopho glans umthondo. Kuyindima yomchamo kanye nokuchama kwesidoda .

Kwabesilisa, ukukhishwa komchamo emzimbeni kwenziwa ngepipi.I- urethra idonsa isinye nge- prostate gland lapho ihlanganiswa khona ne- ejaculatory duct, bese iqhubekela phambili epenis.

  1. McCracken, Kevin G. (2000). "The 20-cm Spiny Penis of the Argentine Lake Duck (Oxyura vittata)". The Auk 117 (3): 820–825. doi:10.2307/4089612. JSTOR 4089612. http://www.bio.miami.edu/mccracken/reprints/auk-117-820.pdf. 
  2. McCracken, Kevin G. (2001). "Sexual selection: Are ducks impressed by drakes' display?". Nature 413 (6852). doi:10.1038/35093160. http://www.bio.miami.edu/mccracken/reprints/nature-413-128.pdf. 
  3. Eastman, p. 23.
  4. Coddington and Cockburn, p. 366.
  5. "Tinamiformes". Tinamiformes. I: Ostrich to Ducks.