A report on Penis

Mallard pseudo-penis
Females have corkscrew vaginas with many blind pockets designed for difficult penetration and to prevent becoming pregnant. This reduced the likelihood of fertilization by unwanted aggressors in favor of fitter mates.
External male genitalia of a Labrador Retriever
Penises of minke whales on display at the Icelandic Phallological Museum
Genitorinary system of a raccoon (Procyon lotor)
Penis of a human, with pubic hair removed to show anatomical detail
The spine-covered penis of Callosobruchus analis, a bean weevil

Primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation.

- Penis
Mallard pseudo-penis

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Diagram of the female human reproductive tract and ovaries

Vagina

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Elastic, muscular part of the female genital tract.

Elastic, muscular part of the female genital tract.

Diagram of the female human reproductive tract and ovaries
Pelvic anatomy including organs of the female reproductive system
An illustration showing a cut-away portion of the vagina and upper female genital tract (only one ovary and fallopian tube shown). Circular folds (also called rugae) of vaginal mucosa can be seen.
Medium-power magnification micrograph of a H&E stained slide showing a portion of a vaginal wall. Stratified squamous epithelium and underling connective tissue can be seen. The deeper muscular layers are not shown. The black line points to a fold in the mucosa.
Folds of mucosa (or vaginal rugae) are shown in the front third of a vagina.
A disposable plastic bi-valved vaginal speculum used in gynecological examination
A normal cervix of an adult as seen through the vagina (per vaginam or PV) using a bivalved vaginal speculum. The blades of the speculum are above and below and stretched vaginal walls are seen on the left and right.
Pre-menopausal vaginal mucosa (left) versus menopausal vaginal mucosa (right)
An ultrasound showing the urinary bladder (1), uterus (2), and vagina (3)
The womb represents a powerful symbol as the yoni in Hinduism. Pictured is a stone yoni found in Cát Tiên sanctuary, Lam Dong, Vietnam.
A sheep gives birth by vagina.

The texture of the vaginal walls creates friction for the penis during sexual intercourse and stimulates it toward ejaculation, enabling fertilization.

Transverse section of the penis.

Corpus cavernosum penis

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Transverse section of the penis.
Structure of the penis
The deeper branches of the internal pudendal artery.
The penis in transverse section, showing the bloodvessels.
Male pelvic organs seen from right side.
Diagram of the arteries of the penis.
Cross section of penis.
Medical ultrasonography of a normal penis.

A corpus cavernosum penis (singular) (literally "cave-like body" of the penis, plural corpora cavernosa) is one of a pair of sponge-like regions of erectile tissue, which contain most of the blood in the penis during an erection.

Vulvas of different women (pubic hair removed in some cases)

Vulva

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The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs.

The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs.

Vulvas of different women (pubic hair removed in some cases)
Labeled image of a vulva, showing external and internal views
Vulva with visible parts of the clitoris and the parts lying under the skin
Muscles underlying the vulva and perineum
The length of the labia minora varies significantly between women: while the labia majora completely enclose the labia minora in some women (top row), in other women they protrude and are clearly visible in upright standing position (bottom row). Colloquially, these variations of the labia are also referred to as "innies" and "outies".
Genital tubercle of female at fourteen weeks
Development of genitals showing homologues from indifferent at A to both sexes - female on right
Development of genitals showing homologues from indifferent to both sexes
Non-aroused vulva on the left and a sexually aroused vulva on the right with enlarged and shiny labia minora from vaginal lubrication and vasocongestion
Water warts of molluscum contagiosum
Pubic hair with crab lice
The Labia pride movement resents the ideals of female cosmetic genital surgeries: The Muff March in London, 2011
Female genital piercings include the Nefertiti piercing central and the Christina piercing pictured on either side
Derived from traditional symbols, Hanabira scarification is intended to decorate the pubic area
A gynaecological examination being carried out in 1822
Japanese artist Megumi Igarashi with vulva portrayal
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Glans clitoris with small distance to the opening
Glans clitoris with medium distance to the opening
Lack of contact of the clitoral glans with the penis
Contact of the clitoral glans with the penis with small CUMD
Classification of the 200 women into CUMD categories
Selection of women studied and interviewed
Vulva handsign used as a yogic mudra
Attic red-figure lid. Three female organs and a winged phallus.
Yoni at Mahadev temple
Glans clitoris with medium distance to the opening

The clitoris is the homologue of the penis, and the clitoral hood is the female equivalent of the male foreskin, and may be partially or completely hidden within the pudendal cleft.

Penile sheath of a Great Dane

Penile sheath

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Penile sheath of a Great Dane
Penile sheath of a Chihuahua with Cryptorchidism

Almost all mammal penises have foreskins or prepuce, although in non-human cases the foreskin is usually a sheath (sometimes called the preputial sheath, praeputium or penile sheath ) into which the whole penis is retracted.

Penile spines

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Many mammalian species have developed keratinized penile spines along the glans and/or shaft, which may be involved in sexual selection.

Many mammalian species have developed keratinized penile spines along the glans and/or shaft, which may be involved in sexual selection.

Upon withdrawal of a cat's penis, the spines rake the walls of the female's vagina, which may serve as a trigger for ovulation.

An everted hemipenis of a North American rattlesnake (Crotalus adamanteus).

Hemipenis

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One of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards).

One of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards).

An everted hemipenis of a North American rattlesnake (Crotalus adamanteus).
Common House Geckos, mating, ventral view with hemipenis inserted in the cloaca
Hemipenes on the western diamondback rattlesnake (Crotalus atrox)

Squamate hemipenes also develop from a different cell origin, originating from the same embryonic cells that produce the limbs, whereas mammalian penises arise from the embryonic cells that develop the tail.

Diagrams to illustrate the changes in the cloaca in mammals during development. A, early embryonic stage, showing the cloaca receiving the urinary bladder, the rectum, and the Wolffian duct, as in non-therian vertebrates. B, later stage, showing the beginning of the fold which divides the cloaca into a ventral urogenital sinus which receives the urinary bladder, Wolffian ducts, and ureters, and into a dorsal part which receives the rectum. C, further progress of the fold, dividing the cloaca into urogenital sinus and rectum; the ureter has separated from the Wolffian duct and is shifting anteriorly. D, completion of the fold, showing complete separation of the cloaca into ventral urogenital sinus and dorsal rectum.

Cloaca

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Posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals.

Posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals.

Diagrams to illustrate the changes in the cloaca in mammals during development. A, early embryonic stage, showing the cloaca receiving the urinary bladder, the rectum, and the Wolffian duct, as in non-therian vertebrates. B, later stage, showing the beginning of the fold which divides the cloaca into a ventral urogenital sinus which receives the urinary bladder, Wolffian ducts, and ureters, and into a dorsal part which receives the rectum. C, further progress of the fold, dividing the cloaca into urogenital sinus and rectum; the ureter has separated from the Wolffian duct and is shifting anteriorly. D, completion of the fold, showing complete separation of the cloaca into ventral urogenital sinus and dorsal rectum.
Cloaca of a female bird
Cloaca of a male bird
A roseate spoonbill excreting urine in flight
Cloacal opening in an Australian brushtail possum
Some aquatic turtle species can breathe underwater using a process known as cloacal respiration. In this process the turtles pump water into their cloacal orifice (labeled 1) by contracting muscles in their inguinal pocket. The water then travels to the cloacal bursae (labeled 2), which are a pair of internal pouch-like structures. The cloacal bursae are lined with long fimbriae (labeled 3), which is the site of gas exchange.
Cloaca of a Red-tailed hawk

For some birds, such as ostriches, cassowaries, kiwi, geese, and some species of swans and ducks, the males do not use the cloaca for reproduction, but have a phallus.

Anatidae

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The Anatidae are the biological family of water birds that includes ducks, geese, and swans.

The Anatidae are the biological family of water birds that includes ducks, geese, and swans.

Landing mallard drake
Anatidae: Eurasian teal (Anas crecca), gadwall (Anas strepera), northern pintail (Anas acuta), mallard (Anas platyrhynchos), greater scaup (Aythya marila), long-tailed duck (Clangula hyemalis), northern shoveler (Anas clypeata), garganey (Anas querquedula), Eurasian wigeon (Anas penelope), ferruginous duck (Aythya nyroca), common goldeneye (Bucephala clangula), common merganser (Mergus merganser), smew (Mergellus albellus), tufted duck (Aythya fuligula), red-breasted merganser (Mergus serrator), common pochard (Aythya ferina). Post of Belarus, 1996.
A male mallard duck
Maned duck is the only living member of the genus Chenonetta
Black swan (Cygnus atratus) skeleton on display at the Museum of Osteology.

Anatidae is a large proportion of the 3% of bird species to possess a penis, though they vary significantly in size, shape, and surface elaboration.

Georges Cuvier's original illustration of an octopus hectocotylus, which he named Hectocotyle octopodis

Hectocotylus

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One of the arms of male cephalopods that is specialized to store and transfer spermatophores to the female.

One of the arms of male cephalopods that is specialized to store and transfer spermatophores to the female.

Georges Cuvier's original illustration of an octopus hectocotylus, which he named Hectocotyle octopodis

Depending on the species, the male may use it merely as a conduit to the female, analogously to a penis in other animals, or he may wrench it off and present it to the female.

Cross section showing the two corpora cavernosa near the top surface of the penis, and the corpus spongiosum surrounding the urethra near the bottom surface.

Erectile tissue

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Tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood.

Tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood.

Cross section showing the two corpora cavernosa near the top surface of the penis, and the corpus spongiosum surrounding the urethra near the bottom surface.

Erectile tissue exists in places such as the corpora cavernosa of the penis, and in the clitoris or in the bulbs of vestibule.