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

54 related topics with Alpha

Overall

The internal anatomy of the human vulva, with the clitoral hood and labia minora indicated as lines. The clitoris extends from the visible portion to a point below the pubic bone.

Clitoris

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Female sex organ present in mammals, ostriches and a limited number of other animals.

Female sex organ present in mammals, ostriches and a limited number of other animals.

The internal anatomy of the human vulva, with the clitoral hood and labia minora indicated as lines. The clitoris extends from the visible portion to a point below the pubic bone.
Stages in the development of the clitoris
Created by Helen O'Connell using MRI, the first 3D image of a clitoris in an erect state with the adjacent organs of the uterus and urinary bladder
Clitoris; deep dissection
A partially exposed clitoral glans, which can't be fully exposed due to a mild case of adhesions to the clitoral hood
Structures of the vulva, including external and internal parts of the clitoris
The clitoral hood has a normal anatomical variation in size and appearance in different adult women: while it is completely covered by the labia majora in some women, standing with their legs closed, in others it is pronounced and clearly visible.
Clitoral hood (1) and clitoris (2). Labia are spread apart on the bottom image.
An enlarged clitoris due to clitoromegaly
De re anatomica
A Georg Ludwig Kobelt illustration of the anatomy of the clitoris
Girl protesting for clitoris-awareness at a women's rights rally in Paris, 2019
With a urogenital system in which the female urinates, mates and gives birth via an enlarged, erectile clitoris, female spotted hyenas are the only female mammals devoid of an external vaginal opening.
Male and female reproductive systems of the spotted hyena, from Schmotzer & Zimmerman, Anatomischer Anzeiger (1922). Abb. 1 (Fig. 1.) Male reproductive anatomy. Abb. 2 (Fig. 2.) Female reproductive anatomy. Principal abbreviations (from Schmotzer & Zimmerman) are: T, testis; Vd, vas deferens; BU, urethral bulb; Ur, urethra; R, rectum; P, penis; S, scrotum; O, ovary; FT, tuba Fallopii; RL, ligament uteri; Ut, uterus; CC, Corpus clitoris. Remaining abbreviations, in alphabetical order, are: AG, parotid analis; B, vesica urinaria; CG, parotid Cowperi; CP, Corpus penis; CS, corpus spongiosum; GC, glans; GP, glans penis; LA, levator ani muscle; Pr, prepuce; RC, musculus retractor clitoris; RP, Musculus retractor penis; UCG, Canalis urogenital.

Unlike the penis, the male homologue (equivalent) to the clitoris, it usually does not contain the distal portion (or opening) of the urethra and is therefore not used for urination.

Three columns of erectile tissue make up most of the volume of the penis.

Erection

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Three columns of erectile tissue make up most of the volume of the penis.
8 stages of erection
Various erection angle and shape of penises.
An erect horse penis

An erection (clinically: penile erection or penile tumescence) is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged.

The urethra transports urine from the bladder to the outside of the body. This image shows (a) a female urethra and (b) a male urethra.

Urethra

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Tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males.

Tube that connects the urinary bladder to the urinary meatus for the removal of urine from the body of both females and males.

The urethra transports urine from the bladder to the outside of the body. This image shows (a) a female urethra and (b) a male urethra.
The human male urethra laid open on its anterior (upper) surface
Micrograph of urethral cancer (urothelial cell carcinoma), a rare problem of the urethra.
Position of the urethra in males
Transverse section of the penis
Male urethral opening on glans penis
Female urethral opening within vulval vestibule
Muscles of the female perineum
Urethra. Deep dissection. Serial cross section.
Diagram which depicts the membranous urethra and the spongy urethra of a male

Its length differs between the sexes, because it passes through the penis in males.

Baculum of a dog's penis; the arrow shows the urethral sulcus.

Baculum

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Baculum of a dog's penis; the arrow shows the urethral sulcus.
A raccoon baculum
Walrus baculum, around 22 in long

The baculum (also penis bone, penile bone, or os penis, os genitale or os priapi ) is a bone found in the penis of many placental mammals.

A flaccid penis, with surrounding pubic hair removed to show anatomical detail

Human penis

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External male intromittent organ that additionally serves as the urinal duct.

External male intromittent organ that additionally serves as the urinal duct.

A flaccid penis, with surrounding pubic hair removed to show anatomical detail
Lateral cross section of the penis
Anatomical diagram of a human penis
Various sized penises
Stages in the development of the male external genitalia
A urinating puer mingens by Annibale Carracci, 1600, Palazzo Farnese
The development of a penile erection, also showing the foreskin gradually retracting over the glans. 
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See also: Commons image gallery''
A ventral view of a penis flaccid (left) and erect (middle); a dorsal view of a penis erect (right).
Hypospadias
Kanamara Matsuri festival in Japan
Papuan man wearing traditional penis sheath
A labelled dorsal view of a circumcised penis: (1) Shaft, (2) Circumcision scar, (3) Corona, (4) Glans, (5) Meatus.
Dissection showing the fascia of the penis as well as several surrounding structures
Image showing innervation and blood-supply of the human male external genitalia

The main parts are the root (radix); the body (corpus); and the epithelium of the penis including the shaft skin and the foreskin (prepuce) covering the glans penis.

The sex organs of a green algae Chara are the male antheridia (red) and female archegonia (brown).

Sex organ

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Any part of an animal or plant that is involved in sexual reproduction.

Any part of an animal or plant that is involved in sexual reproduction.

The sex organs of a green algae Chara are the male antheridia (red) and female archegonia (brown).
The female genitalia of Lepidoptera

The Latin term genitalia, sometimes anglicized as genitals, is used to describe the externally visible sex organs: in male mammals, the penis and scrotum; and in female mammals, the vulva and its organs.

Human glans penis (dorsal view)

Glans penis

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Bulbous structure at the distal end of the human penis that is the most sensitive erogenous zone and primary anatomical source of male sexual pleasure.

Bulbous structure at the distal end of the human penis that is the most sensitive erogenous zone and primary anatomical source of male sexual pleasure.

Human glans penis (dorsal view)
The male anatomy showing the location of the glans penis
Internal anatomy of human glans penis: 1. Fascia penis 2. Corpus cavernosum 3. Coronal sulcus 4. Corona of glans 5. Foreskin 6. Glans penis 7. Meatus of the urethra 8. Navicular fossa of male urethra 9. Tunica albuginea of penis 10. Corpus spongiosum 11. Urethra

In comparison, the glans of felids is short and spiny, while that of viverrids is smooth and long.

A stallion

Stallion

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Male horse that has not been gelded .

Male horse that has not been gelded .

A stallion
Mustang stallion (right) with part of his band of mares and foals
Stallion exhibiting the flehmen response
Genitourinary system of a stallion
A stallion's secondary characteristics include heavier muscling for a given breed than is seen in mares or geldings, often with considerable development along the crest of the neck, as shown in this image.
Even well-trained stallions require firm and consistent handling by experienced individuals.
Aggressive and even violent behavior between stallions not habitually living together or in the presence of mares adds to the challenges in stallion management.
Provided with sufficient space and food with no distractions from mares in estrus, even stallions previously used for breeding may coexist peacefully. Not all individuals are suited for this kind of arrangement, however.
Stallions are capable of achieving a high level of discipline and training.

the penis, within the "penile sheath". Stallions have a vascular penis. When non-erect, it is quite flaccid and contained within the sheath. The retractor penis muscle is relatively underdeveloped. Erection and protrusion take place gradually, by the increasing tumescence of the erectile vascular tissue in the corpus cavernosum penis. When not erect, the penis is housed within the prepuce, 50 cm long and 2.5 to 6 cm in diameter with the distal end 15 to 20 cm. The retractor muscle contracts to retract the penis into the sheath and relaxes to allow the penis to extend from the sheath. When erect, the penis doubles in length and thickness and the glans increases by 3 to 4 times. The urethra opens within the urethral fossa, a small pouch at the distal end of the glans. A structure called the urethral process projects beyond the glans.

Manneken Pis depicts a urinating boy (puer mingens).

Urination

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Release of urine from the urinary bladder through the urethra to the outside of the body.

Release of urine from the urinary bladder through the urethra to the outside of the body.

Manneken Pis depicts a urinating boy (puer mingens).
The interior of the bladder
Male dog using urine to mark a spot with his scent.
Urinating woman
Urinating man
Painting showing the physician Constantine the African accepting urine samples for diagnosis
Location of external urethral orifice in adult human male
Location of the bladder and urethra in adult human female (sagittal section)
Woodcut of a puer mingens, from the Hypnerotomachia Poliphili, 1499
Public toilet outside the Philadelphia City Hall
Indecency, 1799 by Cruikshank
Woman Urinating, etching, Rembrandt van Rijn, 1631
A man uses a urinal while urinating in a standing position.
Body position taken by a woman for urination into many female urinals: floating half squat or "skier position".
Urination in Greek antique art: Hetaera urinating into a skyphos
A horse urinating while in formation with the Queens Guards
A maned wolf urinating on a tree to mark his territory
A cheetah marking a tree with urine
Jeanneke Pis

In placental mammals, urine is drained through the urinary meatus, a urethral opening in the male penis or female vulval vestibule.

Ejaculation example

Ejaculation

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Discharge of semen from the male reproductory tract as a result of an orgasm.

Discharge of semen from the male reproductory tract as a result of an orgasm.

Ejaculation example
Diagram of the male pelvic and reproductive organs

A usual precursor to ejaculation is the sexual arousal of the male, leading to the erection of the penis, though not every arousal nor erection leads to ejaculation.