Human penis
Encyclopedia
The human penis is an external sexual organ
of male
human
s. It is a reproductive, intromittent organ
that additionally serves as the urinal duct
.
The human penis is made up of three columns of tissue
: two corpora cavernosa
lie next to each other on the dorsal side and one corpus spongiosum
lies between them on the ventral side.
The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis
, which supports the foreskin
, or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenum
, or frenulum. The rounded base of the glans is called the corona
. The perineal raphe
is the noticeable line along the underside of the penis.
The urethra
, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus
, lies on the tip of the glans penis. It is a passage both for urine
and for the ejaculation
of semen
. Sperm
are produced in the testes and stored in the attached epididymis
. During ejaculation, sperm are propelled up the vas deferens
, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicle
s and the vas deferens turns into the ejaculatory duct
s, which join the urethra inside the prostate gland. The prostate as well as the bulbourethral gland
s add further secretions, and the semen is expelled through the penis.
The raphe
is the visible ridge between the lateral halves of the penis, found on the ventral or underside of the penis, running from the meatus (opening of the urethra) across the scrotum
to the perineum
(area between scrotum and anus
).
The human penis differs from those of most other mammals, as it has no baculum
, or erectile bone, and instead relies entirely on engorgement with blood to reach its erect state
. It cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass.
, the penis, scrotum
and testicles will begin to develop. During the process, pubic hair
grows above and around the penis. A large-scale study assessing penis size in thousands of 17–19 year old males found no difference in average penis size between 17 year olds and 19 year olds. From this, it can be concluded that penile growth is typically complete not later than age 17, and possibly earlier.
The glans
of the penis is homologous
to the clitoral glans
; the corpora cavernosa are homologous to the body of the clitoris; the corpus spongiosum is homologous to the vestibular bulbs
beneath the labia minora; the scrotum, homologous to the labia minora
and labia majora
; and the foreskin, homologous to the clitoral hood
. The raphe does not exist in females, because there, the two halves are not connected.
An erection is the stiffening and rising of the penis, which occurs during sexual arousal
, though it can also happen in non-sexual situations. The primary physiological mechanism that brings about erection is the autonomic dilation
of arteries supplying blood
to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.
Erection facilitates sexual intercourse
though it is not essential for various other sexual activities.
that holds it in position.
The following table shows how common various erection angles are for a standing male, out of a sample of 1,564 males aged 20 through 69. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common.
from the penis, and is usually accompanied by orgasm
. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis. It is usually the result of sexual stimulation
, which may include prostate
stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep
(known as a nocturnal emission
or wet dream). Anejaculation is the condition of being unable to ejaculate.
Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system
, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerve
s S2–4 via the pudendal nerve
. A refractory period succeeds the ejaculation, and sexual stimulation precedes it.
or decorated by other body art
. Other than circumcision, genital alterations are almost universally elective and usually for the purpose of aesthetics or increased sensitivity. Piercings of the penis include the Prince Albert
, the apadravya, the ampallang, the dydoe, and the frenum piercing
. Foreskin restoration
or stretching is a further form of body modification
, as well as implants
under the shaft of the penis.
Male to female transsexuals who undergo sex reassignment surgery
, have their penis surgically modified into a neovagina
. Female to male transsexuals may have a phalloplasty
.
Other practices that alter the penis are also performed, although they are rare in Western societies without a diagnosed medical condition. Apart from a penectomy
, perhaps the most radical of these is subincision
, in which the urethra is split along the underside of the penis. Subincision originated among Australian Aborigines, although it is now done by some in the U.S. and Europe.
Penis removal
is another form of alteration done to the penis.
: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. For infant circumcision, modern devices such as the Gomco clamp
, Plastibell
, and Mogen clamp are available.
With all modern devices the same basic procedure is followed. First, the amount of foreskin to be removed is estimated. The foreskin is then opened via the preputial orifice to reveal the glans
underneath and ensured that it is normal. The inner lining of the foreskin (preputial epithelium) is then separated from its attachment to the glans. The device is then placed (this sometimes requires a dorsal slit) and remains there until blood flow has stopped. Finally, part, or all, of the foreskin is then removed.
Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from masturbation
or intercourse after the operation to allow the wound to heal. In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions. After hospital circumcision, the foreskin may be used in biomedical research, consumer skin-care products, skin grafts, or β-interferon
-based drugs. In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals. According to Jewish law
, after a Brit milah
, the foreskin should be buried.
There is controversy surrounding circumcision. Advocates of circumcision argue, for example, that it provides important health advantages that outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period. Opponents of circumcision argue, for example, that the practice has been and is still defended through the use of various myths; that it interferes with normal sexual function; that it is extremely painful; and that when performed on infants and children, it violates the individual's human rights
.
The American Medical Association
stated in 1999: "Virtually all current policy statements from specialty societies and medical organizations do not recommend routine neonatal circumcision, and support the provision of accurate and unbiased information to parents to inform their choice."
The World Health Organization (WHO; 2007), the Joint United Nations Programme on HIV/AIDS
(UNAIDS; 2007), and the Centers for Disease Control and Prevention
(CDC; 2008) state that evidence indicates male circumcision significantly reduces the risk of HIV
acquisition by men during penile-vaginal sex, but also state that circumcision only provides partial protection and should not replace other interventions to prevent transmission of HIV. In addition, some doctors have expressed concern over the policy and the data that supports it.
, China
. A man at 44 sustained an injury after an accident and his penis was severed; urination
became difficult as his urethra was partly blocked. A recently brain-dead man, aged 23, was selected for the transplant. Despite atrophy
of blood vessels and nerves, the arteries, veins, nerves and the corpora spongiosa were successfully matched. But, on 19 September (after two weeks), the surgery was reversed because of a severe psychological problem (rejection) by the recipient and his wife.
In 2009 researchers Chen, Eberli, Yoo and Atala have produced bioengineered
penises and implanted them on rabbits. The animals were able to obtain erection
and copulate, with 10 of 12 rabbits achieving ejaculation
. This study shows that in the future it could be possible to produce artificial penises for replacement surgeries or phalloplasties
.
While results vary across studies, the consensus is that the average erect
human penis is approximately 12.9–15 cm (5.1–5.9 in) in length with 95% of adult males falling within the interval (10.7 cm, 19.1 cm) or (4.23 in, 7.53 in). The typical girth or circumference
is approximately 12.3 cm (4.84 in) when fully erect. The average
penis size is slightly larger than the median
size (i.e., most penises are below average in size).
A research project, summarizing dozens of published studies conducted by physicians of different nationalities, shows that, worldwide, erect-penis size averages vary between 9.6 and 16 cm (3.8 and 6.3 in). It has been suggested that this difference is caused not only by genetics
but also by environmental factors such as culture
, diet
, chemical/pollution exposure, etc. Endocrine disruption resulting from chemical exposure has been linked to genital deformation in both sexes (among many other problems).
Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
The longest officially documented human penis was found by Doctor Robert Latou Dickinson
. It was 34.3 cm (13.5 in) long and 15.9 cm (6.26 in) around.
Sex organ
A sex organ, or primary sexual characteristic, as narrowly defined, is any of the anatomical parts of the body which are involved in sexual reproduction and constitute the reproductive system in a complex organism; flowers are the reproductive organs of flowering plants, cones are the reproductive...
of male
Male
Male refers to the biological sex of an organism, or part of an organism, which produces small mobile gametes, called spermatozoa. Each spermatozoon can fuse with a larger female gamete or ovum, in the process of fertilization...
human
Human
Humans are the only living species in the Homo genus...
s. It is a reproductive, intromittent organ
Intromittent organ
An intromittent organ is a general term for an external organ of a male organism that is specialized to deliver sperm during copulation. Intromittent organs are found most often in terrestrial species, as most aquatic species fertilize their eggs externally, although there are...
that additionally serves as the urinal duct
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...
.
Parts
- Root of the penis (radix): It is the attached part, consisting of the bulb of penisBulb of penisJust before each crus of the penis meets its fellow it presents a slight enlargement, named by Kobelt the bulb of the corpus spongiosum penis.It is homologous to the vestibular bulbs in females....
in the middle and the crus of penisCrus of penisFor their anterior three-fourths the corpora cavernosa penis lie in intimate apposition with one another, but behind they diverge in the form of two tapering processes, known as the crura, which are firmly connected to the ischial rami....
, one on either side of the bulb. It lies within the superficial perineal pouch. - Body of the penis (corpus): It has two surfaces: dorsal (posterosuperior in the erect penis), and ventral or urethral (facing downwards and backwards in the flaccid penis). The ventral surface is marked by a grove in a lateral direction.
Structure
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
: two corpora cavernosa
Corpus cavernosum penis
The corpus cavernosum penis is one of a pair of sponge-like regions of erectile tissue which contain most of the blood in the penis during penile erection...
lie next to each other on the dorsal side and one corpus spongiosum
Corpus spongiosum
Corpus spongiosum is the mass of spongy tissue surrounding the male urethra within the penis...
lies between them on the ventral side.
The enlarged and bulbous-shaped end of the corpus spongiosum forms the glans penis
Glans penis
The glans penis is the sensitive bulbous structure at the distal end of the penis. The glans penis is anatomically homologous to the clitoral glans of the female...
, which supports the foreskin
Foreskin
In male human anatomy, the foreskin is a generally retractable double-layered fold of skin and mucous membrane that covers the glans penis and protects the urinary meatus when the penis is not erect...
, or prepuce, a loose fold of skin that in adults can retract to expose the glans. The area on the underside of the penis, where the foreskin is attached, is called the frenum
Frenulum of prepuce of penis
The word frenulum on its own is often used for the frenulum of prepuce of penis, which is an elastic band of tissue under the glans penis that connects to the prepuce, or foreskin to the vernal mucosa, and helps contract the prepuce over the glans. This is sometimes colloquially known as the "banjo...
, or frenulum. The rounded base of the glans is called the corona
Corona of glans penis
The corona of glans penis refers to the circumference of the base of the glans penis in human males which forms a rounded projecting border, overhanging a deep retroglandular sulcus, behind which is the neck of the penis....
. The perineal raphe
Perineal raphe
The perineal raphe is a visible line or ridge of tissue on the human body that extends from the anus through the perineum.In men, this raphe continues through the midline of the scrotum and upwards through the posterior midline aspect of the penis...
is the noticeable line along the underside of the penis.
Urethra
In anatomy, the urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids out of the body. In males, the urethra travels through the penis, and carries semen as well as urine...
, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus
External urethral orifice (male)
The external urethral orifice is the external opening or meatus of the urethra, normally placed at the tip of glans penis; it presents as a vertical slit, possibly bounded on either side by two small labia-like projections, In some cases the slit may be more rounded. This occurs naturally in some...
, lies on the tip of the glans penis. It is a passage both for urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
and for the ejaculation
Ejaculation
Ejaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...
of semen
Semen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
. Sperm
Spermatozoon
A spermatozoon is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote...
are produced in the testes and stored in the attached epididymis
Epididymis
The epididymis is part of the male reproductive system and is present in all male amniotes. It is a narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens. A similar, but probably non-homologous, structure is found in cartilaginous...
. During ejaculation, sperm are propelled up the vas deferens
Vas deferens
The vas deferens , also called ductus deferens, , is part of the male anatomy of many vertebrates; they transport sperm from the epididymis in anticipation of ejaculation....
, two ducts that pass over and behind the bladder. Fluids are added by the seminal vesicle
Seminal vesicle
The seminal vesicles or vesicular glands are a pair of simple tubular glands posteroinferior to the urinary bladder of male mammals...
s and the vas deferens turns into the ejaculatory duct
Ejaculatory duct
-Anatomy:The ejaculatory ducts are paired structures in male anatomy. Each ejaculatory duct is formed by the union of the vas deferens with the duct of the seminal vesicle. They pass through the prostate, and open into the urethra at the Colliculus seminalis...
s, which join the urethra inside the prostate gland. The prostate as well as the bulbourethral gland
Bulbourethral gland
A bulbourethral gland, also called a Cowper's gland for anatomist William Cowper, is one of two small exocrine glands present in the reproductive system of human males...
s add further secretions, and the semen is expelled through the penis.
The raphe
Perineal raphe
The perineal raphe is a visible line or ridge of tissue on the human body that extends from the anus through the perineum.In men, this raphe continues through the midline of the scrotum and upwards through the posterior midline aspect of the penis...
is the visible ridge between the lateral halves of the penis, found on the ventral or underside of the penis, running from the meatus (opening of the urethra) across the scrotum
Scrotum
In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...
to the perineum
Perineum
In human anatomy, the perineum is a region of the body including the perineal body and surrounding structures...
(area between scrotum and anus
Anus
The anus is an opening at the opposite end of an animal's digestive tract from the mouth. Its function is to control the expulsion of feces, unwanted semi-solid matter produced during digestion, which, depending on the type of animal, may be one or more of: matter which the animal cannot digest,...
).
The human penis differs from those of most other mammals, as it has no baculum
Baculum
The baculum is a bone found in the penis of most mammals. It is absent in humans, but present in other primates, such as the gorilla and chimpanzee.The bone aids in sexual intercourse.-Purpose:...
, or erectile bone, and instead relies entirely on engorgement with blood to reach its erect state
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
. It cannot be withdrawn into the groin, and it is larger than average in the animal kingdom in proportion to body mass.
Penile growth and puberty
On entering pubertyPuberty
Puberty is the process of physical changes by which a child's body matures into an adult body capable of reproduction, as initiated by hormonal signals from the brain to the gonads; the ovaries in a girl, the testes in a boy...
, the penis, scrotum
Scrotum
In some male mammals the scrotum is a dual-chambered protuberance of skin and muscle containing the testicles and divided by a septum. It is an extension of the perineum, and is located between the penis and anus. In humans and some other mammals, the base of the scrotum becomes covered with curly...
and testicles will begin to develop. During the process, pubic hair
Pubic hair
Pubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region....
grows above and around the penis. A large-scale study assessing penis size in thousands of 17–19 year old males found no difference in average penis size between 17 year olds and 19 year olds. From this, it can be concluded that penile growth is typically complete not later than age 17, and possibly earlier.
Sexual homology
In short, this is a known list of sex organs that evolve from the same tissue in females and males.The glans
Glans penis
The glans penis is the sensitive bulbous structure at the distal end of the penis. The glans penis is anatomically homologous to the clitoral glans of the female...
of the penis is homologous
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
to the clitoral glans
Clitoral glans
The clitoral glans is an external portion of the clitoris.- Anatomy :It is covered by the clitoral hood, which is also external and attached to the labia minora...
; the corpora cavernosa are homologous to the body of the clitoris; the corpus spongiosum is homologous to the vestibular bulbs
Vestibular bulbs
The vestibular bulbs, also known as the clitoral bulbs, are aggregations of erectile tissue that are an internal part of the clitoris. They can also be found throughout the vestibule: next to the clitoral body, clitoral crura, urethra, urethral sponge, and vagina.They are to the left and right of...
beneath the labia minora; the scrotum, homologous to the labia minora
Labia minora
The labia minora , also known as the inner labia, inner lips, or nymphae, are two flaps of skin on either side of the human vaginal opening, situated between the labia majora...
and labia majora
Labia majora
The labia majora are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum and form the lateral boundaries of the pudendal cleft, which contains the labia minora, interlabial sulci, clitoral hood, clitoral glans, frenulum clitoridis, the...
; and the foreskin, homologous to the clitoral hood
Clitoral hood
In female human anatomy, the clitoral hood, , is a fold of skin that surrounds and protects the clitoral glans. It develops as part of the labia minora and is homologous with the foreskin in male genitals.-Variation:This is a protective hood of skin that covers the clitoral glans...
. The raphe does not exist in females, because there, the two halves are not connected.
Erection
Sexual arousal
Sexual arousal, or sexual excitement, is the arousal of sexual desire, during or in anticipation of sexual activity. Things that precipitate human sexual arousal are called erotic stimuli, or colloquially known as turn-ons. There are many potential stimuli, both physical or mental, which can cause...
, though it can also happen in non-sexual situations. The primary physiological mechanism that brings about erection is the autonomic dilation
Vasodilation
Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
of arteries supplying blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
to the penis, which allows more blood to fill the three spongy erectile tissue chambers in the penis, causing it to lengthen and stiffen. The now-engorged erectile tissue presses against and constricts the veins that carry blood away from the penis. More blood enters than leaves the penis until an equilibrium is reached where an equal volume of blood flows into the dilated arteries and out of the constricted veins; a constant erectile size is achieved at this equilibrium.
Erection facilitates sexual intercourse
Sexual intercourse
Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...
though it is not essential for various other sexual activities.
Erection angle
Although many erect penises point upwards (see illustration), it is common and normal for the erect penis to point nearly vertically upwards or nearly vertically downwards or even horizontally straight forward, all depending on the tension of the suspensory ligamentSuspensory ligament of the penis
In males, the suspensory ligament of the penis is attached to the pubic symphysis, which holds the penis close to the pubic bone and supports it when erect....
that holds it in position.
The following table shows how common various erection angles are for a standing male, out of a sample of 1,564 males aged 20 through 69. In the table, zero degrees is pointing straight up against the abdomen, 90 degrees is horizontal and pointing straight forward, while 180 degrees would be pointing straight down to the feet. An upward pointing angle is most common.
| angle (º) from vertically upwards |
Percent of males |
|---|---|
| 0–30 | 5 |
| 30–60 | 30 |
| 60–85 | 31 |
| 85–95 | 10 |
| 95–120 | 20 |
| 120–180 | 5 |
Ejaculation
Ejaculation is the ejecting of semenSemen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
from the penis, and is usually accompanied by orgasm
Orgasm
Orgasm is the peak of the plateau phase of the sexual response cycle, characterized by an intense sensation of pleasure...
. A series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis. It is usually the result of sexual stimulation
Sexual stimulation
Sexual stimulation is any stimulus that leads to, enhances and maintains sexual arousal, and may lead to ejaculation and/or orgasm...
, which may include prostate
Prostate
The prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
stimulation. Rarely, it is due to prostatic disease. Ejaculation may occur spontaneously during sleep
Sleep
Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...
(known as a nocturnal emission
Nocturnal emission
A nocturnal emission involves either ejaculation during sleep for a male, or lubrication of the vagina for a female. It is also called a wet dream, and is sometimes considered a type of spontaneous orgasm....
or wet dream). Anejaculation is the condition of being unable to ejaculate.
Ejaculation has two phases: emission and ejaculation proper. The emission phase of the ejaculatory reflex is under control of the sympathetic nervous system
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
, while the ejaculatory phase is under control of a spinal reflex at the level of the spinal nerve
Spinal nerve
The term spinal nerve generally refers to a mixed spinal nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body...
s S2–4 via the pudendal nerve
Pudendal nerve
The pudendal nerve is a sensory and somatic nerve in the pelvic region which is a large branch of the sacral plexus that innervates the external genitalia of both sexes, as well as sphincters for the bladder and the rectum...
. A refractory period succeeds the ejaculation, and sexual stimulation precedes it.
Normal variations
- Pearly penile papulesHirsuties papillaris genitalisHirsuties coronae glandis are small saliences on the ridge of the glans of the male genital organs. It is a harmless anatomical variation. They are found significantly more often on uncircumcised men, and on younger men...
are raised bumps of somewhat paler color around the base (sulcus) of the glans which typically develop in men aged 20 to 40, and around 10% of all men are affected. They may be mistaken for warts, but are not harmful or infectious and require no treatment. - Fordyce's spotFordyce's spotFordyce's spots are small, painless, raised, pale, red or white spots or bumps 1 to 3 mm in diameter that may appear on the scrotum, shaft of the penis or on the labia, as well as the inner surface and vermilion border of the lips of the face. They are common in men and women of all ages....
s are small, raised, yellowish-white spots 1–2 mm in diameter that may appear on the penis, which again are common and not infectious. - Sebaceous prominences are raised bumps similar to Fordyce's spots on the shaft of the penis, located at the sebaceous glandSebaceous glandThe sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...
s and are normal. - PhimosisPhimosisPhimosis , from the Greek phimos ), is a condition where, in men, the foreskin cannot be fully retracted over the glans penis...
is an inability to retract the foreskin fully, is harmless in infancy and pre-pubescence, occurring in about 8% of boys at age 10. According to the British Medical Association, treatment (topical steroid cream and/or manual stretching) does not need to be considered until age 19. - Curvature: few penises are completely straight, with curves commonly seen in all directions (up, down, left, right). Sometimes the curve is very prominent but it rarely inhibits sexual intercourseSexual intercourseSexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...
. Curvature as great as 30° is considered normal and medical treatment is rarely considered unless the angle exceeds 45°. Changes to the curvature of a penis may be caused by Peyronie's diseasePeyronie's diseasePeyronie's Disease Peyronie's Disease Peyronie's Disease (also known as "Induratio penis plastica", or more recently Chronic Inflammation of the Tunica Albuginea (CITA), is a connective tissue disorder involving the growth of fibrous plaques in the soft tissue of the penis affecting up to 10% of men...
.
Disorders
- ParaphimosisParaphimosisParaphimosis is an uncommon medical condition where the foreskin becomes trapped behind the glans penis, and cannot be reduced...
is an inability to move the foreskin forward, over the glans. It can result from fluid trapped in a foreskin left retracted, perhaps following a medical procedure, or accumulation of fluid in the foreskin because of frictionFrictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of friction:...
during vigorous sexual activity. - In Peyronie's diseasePeyronie's diseasePeyronie's Disease Peyronie's Disease Peyronie's Disease (also known as "Induratio penis plastica", or more recently Chronic Inflammation of the Tunica Albuginea (CITA), is a connective tissue disorder involving the growth of fibrous plaques in the soft tissue of the penis affecting up to 10% of men...
, anomalous scar tissue grows in the soft tissue of the penis, causing curvature. Severe cases can benefit from surgical correction. - A thrombosisThrombosisThrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
can occur during periods of frequent and prolonged sexual activity, especially fellatioFellatioFellatio is an act of oral stimulation of a male's penis by a sexual partner. It involves the stimulation of the penis by the use of the mouth, tongue, or throat. The person who performs fellatio can be referred to as the giving partner, and the other person is the receiving partner...
. It is usually harmless and self-corrects within a few weeks. - Infection with the herpes virus can occur after sexual contact with an infected carrier; this may lead to the development of herpes sores.
- Pudendal nerve entrapmentPudendal nerve entrapmentPudendal nerve entrapment , also known as Alcock canal syndrome, is an uncommon source of chronic pain, in which the pudendal nerve is entrapped or compressed. Pain is positional and is worsened by sitting...
is a condition characterized by pain on sitting and loss of penile (or clitoral) sensation and orgasm. Occasionally there is a total loss of sensation and orgasm. The pudendal nervePudendal nerveThe pudendal nerve is a sensory and somatic nerve in the pelvic region which is a large branch of the sacral plexus that innervates the external genitalia of both sexes, as well as sphincters for the bladder and the rectum...
can be damaged by narrow, hard bicycle seats and accidents. - Penile fracturePenile fractureA penile fracture is an injury caused by the rupture of the tunica albuginea, which envelops the corpus cavernosum penis. It is most often caused by a blunt trauma to an erect penis.-Presentation:...
can occur if the erect penis is bent excessively. A popping or cracking sound and pain is normally associated with this event. Emergency medical assistance should be obtained. Prompt medical attention lowers likelihood of permanent penile curvature. - In diabetes, peripheral neuropathyPeripheral neuropathyPeripheral neuropathy is the term for damage to nerves of the peripheral nervous system, which may be caused either by diseases of or trauma to the nerve or the side-effects of systemic illness....
can cause tingling in the penile skin and possibly reduced or completely absent sensation. The reduced sensations can lead to injuries for either partner and their absence can make it impossible to have sexual pleasure through stimulation of the penis. Since the problems are caused by permanent nerve damage, preventive treatment through good control of the diabetes is the primary treatment. Some limited recovery may be possible through improved diabetes control. - Erectile dysfunctionErectile dysfunctionErectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
is the inability to develop and maintain an erection sufficiently firm for satisfactory sexual performance. Diabetes is a leading cause, as is natural aging. A variety of treatments exist, including drugs, such as sildenafilSildenafilSildenafil citrate, sold as Viagra, Revatio and under various other trade names, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension . It was originally developed by British scientists and then brought to market by the US-based pharmaceutical company Pfizer...
citrate (marketed as Viagra), which works by vasodilationVasodilationVasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
. - PriapismPriapismPriapism is a potentially harmful and painful medical condition in which the erect penis or clitoris does not return to its flaccid state, despite the absence of both physical and psychological stimulation, within four hours. There are two types of priapism: low-flow and high-flow. Low-flow...
is a painful and potentially harmful medical condition in which the erect penis does not return to its flaccid state. The causative mechanisms are poorly understood but involve complex neurological and vascular factors. Potential complications include ischaemia, thrombosis, and impotence. In serious cases the condition may result in gangreneGangreneGangrene is a serious and potentially life-threatening condition that arises when a considerable mass of body tissue dies . This may occur after an injury or infection, or in people suffering from any chronic health problem affecting blood circulation. The primary cause of gangrene is reduced blood...
, which may necessitate amputationAmputationAmputation is the removal of a body extremity by trauma, prolonged constriction, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for...
. The condition has been associated with a variety of drugs including prostaglandinProstaglandinA prostaglandin is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring....
but not sildenafilSildenafilSildenafil citrate, sold as Viagra, Revatio and under various other trade names, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension . It was originally developed by British scientists and then brought to market by the US-based pharmaceutical company Pfizer...
(Viagra). - LymphangiosclerosisLymphangiosclerosisLymphangiosclerosis is a hardened lymph vessel, although it can feel like a hardened, almost calcified or fibrous, vein. It tends to not share the common blue tint with a vein however. It can be felt as a hardened lump or "Vein" even when the penis is flaccid, and is even more prominent during an...
is a hardened lymph vesselLymph vesselIn anatomy, lymph vessels are thin walled, valved structures that carry lymph. As part of the lymphatic system, lymph vessels are complementary to the cardiovascular system. Lymph vessels are lined by endothelial cells, and deep to that have a thin layer of smooth muscles, and adventitia that bind...
, although it can feel like a hardened, almost calcified or fibrous, vein. It tends not to share the common blue tint with a vein however. It can be felt as a hardened lump or "vein" even when the penis is flaccid, and is even more prominent during an erection. It is considered a benignBenignA benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
physical condition. It is fairly common and can follow a particularly vigorous sexual activity for men, and tends to go away if given rest and more gentle care, for example by use of lubricants. - Carcinoma of the penisCarcinoma of the penisPenile cancer is a malignant growth found on the skin or in the tissues of the penis. A Squamous cell carcinoma usually originating in the glans or foreskin is by far the most common type, occurring in 9 out of 10 cases. Penis cancer tends to develop in men over the age of sixty. Penile cancer is...
is rare with a reported rate of 1 person in 100,000 in developed countries. Circumcision is said to protect against this disease but this notion remains controversial.
Developmental disorders
- HypospadiasHypospadiasHypospadias is a birth defect of the urethra in the male that involves an abnormally placed urinary meatus...
is a developmental disorderDevelopmental disorderDevelopmental disorders occur at some stage in a child's development, often retarding the development. These may include,psychological or physical disorders. The disorder is an impairment in the normal development of motor or cognitive skills that are developed before age 18 in which they are...
where the meatusUrinary meatusThe urinary meatus is an orifice of the urethra. It is the point at which urine and, in males, semen exits the urethra. The meatus features varying degrees of sensitivity to the touch among males and females....
is positioned wrongly at birth. Hypospadias can also occur iatrogenically by the downward pressure of an indwelling urethral catheter. It is usually corrected by surgery. The Intersex Society of North AmericaIntersex Society of North AmericaThe Intersex Society of North America was a non-profit advocacy group founded in 1993 by Cheryl Chase to represent the interest of intersex people. Their objective was to end shame, secrecy, and unwanted genital surgeries...
classifies hypospadias as an intersex condition. They believe in halting all medically unnecessary surgeries, including many of those done on people with hypospadias. - A micropenisMicropenisMicropenis is an unusually small penis. A common criterion is a dorsal erect penile length of at least 2.5 standard deviations smaller than the mean human penis size. The condition is usually recognized shortly after birth...
is a very small penis caused by developmental or congenital problems. - DiphalliaDiphalliaDiphallia, penile duplication , diphallic terata, or diphallasparatus, is a medical condition in which a male infant is born with two penises. This is an extremely rare disorder with only approximately 100 cases of diphallia recorded since the first, reported by Johannes Jacob Wecker in 1609...
, or penile duplication (PD), is the condition of having two penises. However, this disorder is extremely rare.
Alleged and observed psychological disorders
- Penis panicPenis panicKoro is a culture-specific syndrome from Southeast Asia in which the patient has an overpowering belief that his penis is shrinking and will shortly disappear. Also known as shrinking penis, the syndrome is listed in the Diagnostic and Statistical Manual of Mental Disorders...
(koro in MalaysianMalay languageMalay is a major language of the Austronesian family. It is the official language of Malaysia , Indonesia , Brunei and Singapore...
/IndonesianIndonesian languageIndonesian is the official language of Indonesia. Indonesian is a normative form of the Riau Islands dialect of Malay, an Austronesian language which has been used as a lingua franca in the Indonesian archipelago for centuries....
)—delusion of shrinkage of the penis and retraction into the body. This appears to be culturally conditioned and largely limited to Ghana, Sudan, China, Japan, Southeast Asia, and West Africa. - In April 2008, KinshasaKinshasaKinshasa is the capital and largest city of the Democratic Republic of the Congo. The city is located on the Congo River....
, Democratic Republic of Congo, West Africa's 'Police arrested 14 suspected victims (of penis snatching) and sorcerers accused of using black magic or witchcraft to steal (make disappear) or shrink men's penises to extort cash for cure, amid a wave of panic. Arrests were made in an effort to avoid bloodshed seen in Ghana a decade before, when 12 penis snatchers were beaten to death by mobs. - Penis envyPenis envyPenis envy in Freudian psychoanalysis refers to the theorized reaction of a girl during her psychosexual development to the realization that she does not have a penis....
the contested Freudian belief of a woman envying men for having a penis.
Altering the genitalia
The penis is sometimes piercedBody piercing
Body piercing, a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn. The word piercing can refer to the act or practice of body piercing, or to an opening in the body created by this act or practice...
or decorated by other body art
Body art
Body art is art made on, with, or consisting of, the human body. The most common forms of body art are tattoos and body piercings, but other types include scarification, branding, scalpelling, shaping , full body tattoo and body painting.More extreme body art can involve things such as mutilation...
. Other than circumcision, genital alterations are almost universally elective and usually for the purpose of aesthetics or increased sensitivity. Piercings of the penis include the Prince Albert
Prince Albert piercing
For other uses of "Prince Albert", see Prince Albert The Prince Albert is one of the more common male genital piercings...
, the apadravya, the ampallang, the dydoe, and the frenum piercing
Frenum piercing
A frenulum piercing is a type of body piercing located on the underside of the shaft of the penis. A series of parallel frenulum piercings is known as a frenum ladder. A frenum ladder may be extended to include lorum piercings, hafada piercings and guiche piercings.-Placement:Frenum piercings are...
. Foreskin restoration
Foreskin restoration
Foreskin restoration is the process of expanding the residual skin on the penis, via surgical or non-surgical methods. It can be performed for several reasons, among them being a desire to create the appearance of a natural foreskin covering the glans penis, or to increase sexual sensitivity of...
or stretching is a further form of body modification
Body modification
Body modification is the deliberate altering of the human body for any non-medical reason, such as aesthetics, sexual enhancement, a rite of passage, religious reasons, to display group membership or affiliation, to create body art, shock value, or self expression...
, as well as implants
Implant (body modification)
In body modification, an implant is a device placed under the human skin for decorative purposes. Such implants may be subdermal or transdermal...
under the shaft of the penis.
Male to female transsexuals who undergo sex reassignment surgery
Sex reassignment surgery
Sex reassignment surgery is a term for the surgical procedures by which a person's physical appearance and function of their existing sexual characteristics are altered to resemble...
, have their penis surgically modified into a neovagina
Vaginoplasty
thumb|right|300px|Vaginoplasty: the pre-operative aspect , and the post-operative aspect of a [[Labiaplasty|labial reduction]].Vaginoplasty is a reconstructive plastic surgery procedure for correcting the defects and deformities of the vaginal canal and its mucous membrane, and of vulvo-vaginal...
. Female to male transsexuals may have a phalloplasty
Phalloplasty
Phalloplasty refers to the construction of a penis or, sometimes, artificial modification of the penis by surgery, often for cosmetic purposes. It is also occasionally used to refer to penis enlargement....
.
Other practices that alter the penis are also performed, although they are rare in Western societies without a diagnosed medical condition. Apart from a penectomy
Penectomy
Penectomy is the surgical removal of the penis for medical or personal reasons.- Medical Reasons for Penectomy :Cancer, for example, sometimes necessitates removal of part or of the penis. The amount of the penis removed depends on the severity of the cancer. Some men have only the tip of their...
, perhaps the most radical of these is subincision
Subincision
Penile subincision is a form of body modification consisting of a urethrotomy, in which the underside of the penis is incised and the urethra slit open lengthwise, from the urethral opening toward the base...
, in which the urethra is split along the underside of the penis. Subincision originated among Australian Aborigines, although it is now done by some in the U.S. and Europe.
Penis removal
Penis removal
In ancient civilizations, removal of the human penis was sometimes used as a means of demonstrating superiority: armies were sometimes known to sever the penises of their enemies to count the dead, as well as for trophies...
is another form of alteration done to the penis.
Circumcision
The most common form of genital alteration is circumcisionCircumcision
Male circumcision is the surgical removal of some or all of the foreskin from the penis. The word "circumcision" comes from Latin and ....
: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. For infant circumcision, modern devices such as the Gomco clamp
Gomco clamp
A Gomco clamp, otherwise known as a Yellen clamp, is a specialized clamp for performing circumcisions. It was invented by Hiram S. Yellen and Aaron Goldstein in 1934-1935. Gomco stands for the GOldstein Medical COmpany, the original manufacturer of the clamp...
, Plastibell
Plastibell
The Plastibell Circumcision Device is a clear plastic ring with a deep groove running circumferentially designed for circumcising infant males. The Plastibell is placed onto the head of the penis during a 10 minute surgical procedure, and the device will fall off within 3 to 7 days...
, and Mogen clamp are available.
With all modern devices the same basic procedure is followed. First, the amount of foreskin to be removed is estimated. The foreskin is then opened via the preputial orifice to reveal the glans
Glans penis
The glans penis is the sensitive bulbous structure at the distal end of the penis. The glans penis is anatomically homologous to the clitoral glans of the female...
underneath and ensured that it is normal. The inner lining of the foreskin (preputial epithelium) is then separated from its attachment to the glans. The device is then placed (this sometimes requires a dorsal slit) and remains there until blood flow has stopped. Finally, part, or all, of the foreskin is then removed.
Adult circumcisions are often performed without clamps and require 4 to 6 weeks of abstinence from masturbation
Masturbation
Masturbation refers to sexual stimulation of a person's own genitals, usually to the point of orgasm. The stimulation can be performed manually, by use of objects or tools, or by some combination of these methods. Masturbation is a common form of autoeroticism...
or intercourse after the operation to allow the wound to heal. In some African countries, male circumcision is often performed by non-medical personnel under unsterile conditions. After hospital circumcision, the foreskin may be used in biomedical research, consumer skin-care products, skin grafts, or β-interferon
Interferon
Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...
-based drugs. In parts of Africa, the foreskin may be dipped in brandy and eaten by the patient, eaten by the circumciser, or fed to animals. According to Jewish law
Halakha
Halakha — also transliterated Halocho , or Halacha — is the collective body of Jewish law, including biblical law and later talmudic and rabbinic law, as well as customs and traditions.Judaism classically draws no distinction in its laws between religious and ostensibly non-religious life; Jewish...
, after a Brit milah
Brit milah
The brit milah is a Jewish religious circumcision ceremony performed on 8-day old male infants by a mohel. The brit milah is followed by a celebratory meal .-Biblical references:...
, the foreskin should be buried.
There is controversy surrounding circumcision. Advocates of circumcision argue, for example, that it provides important health advantages that outweigh the risks, has no substantial effects on sexual function, has a low complication rate when carried out by an experienced physician, and is best performed during the neonatal period. Opponents of circumcision argue, for example, that the practice has been and is still defended through the use of various myths; that it interferes with normal sexual function; that it is extremely painful; and that when performed on infants and children, it violates the individual's human rights
Human rights
Human rights are "commonly understood as inalienable fundamental rights to which a person is inherently entitled simply because she or he is a human being." Human rights are thus conceived as universal and egalitarian . These rights may exist as natural rights or as legal rights, in both national...
.
The American Medical Association
American Medical Association
The American Medical Association , founded in 1847 and incorporated in 1897, is the largest association of medical doctors and medical students in the United States.-Scope and operations:...
stated in 1999: "Virtually all current policy statements from specialty societies and medical organizations do not recommend routine neonatal circumcision, and support the provision of accurate and unbiased information to parents to inform their choice."
The World Health Organization (WHO; 2007), the Joint United Nations Programme on HIV/AIDS
Joint United Nations Programme on HIV/AIDS
The Joint United Nations Programme on HIV and AIDS, or UNAIDS, is the main advocate for accelerated, comprehensive and coordinated global action on the HIV epidemic....
(UNAIDS; 2007), and the Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
(CDC; 2008) state that evidence indicates male circumcision significantly reduces the risk of HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
acquisition by men during penile-vaginal sex, but also state that circumcision only provides partial protection and should not replace other interventions to prevent transmission of HIV. In addition, some doctors have expressed concern over the policy and the data that supports it.
Surgical replacement
The first successful penis allotransplant surgery was done in September 2005 in a military hospital in GuangzhouGuangzhou
Guangzhou , known historically as Canton or Kwangchow, is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about north-northwest of Hong Kong, Guangzhou is a key national transportation hub and trading port...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. A man at 44 sustained an injury after an accident and his penis was severed; urination
Urination
Urination, also known as micturition, voiding, peeing, weeing, pissing, and more rarely, emiction, is the ejection of urine from the urinary bladder through the urethra to the outside of the body. In healthy humans the process of urination is under voluntary control...
became difficult as his urethra was partly blocked. A recently brain-dead man, aged 23, was selected for the transplant. Despite atrophy
Atrophy
Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations , poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply to the target organ, disuse or lack of exercise or disease intrinsic to the tissue itself...
of blood vessels and nerves, the arteries, veins, nerves and the corpora spongiosa were successfully matched. But, on 19 September (after two weeks), the surgery was reversed because of a severe psychological problem (rejection) by the recipient and his wife.
In 2009 researchers Chen, Eberli, Yoo and Atala have produced bioengineered
Biological engineering
Biological engineering, biotechnological engineering or bioengineering is the application of concepts and methods of biology to solve problems in life sciences, using engineering's own analytical and synthetic methodologies and also its traditional...
penises and implanted them on rabbits. The animals were able to obtain erection
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
and copulate, with 10 of 12 rabbits achieving ejaculation
Ejaculation
Ejaculation is the ejecting of semen from the male reproductory tract, and is usually accompanied by orgasm. It is usually the final stage and natural objective of male sexual stimulation, and an essential component of natural conception. In rare cases ejaculation occurs because of prostatic disease...
. This study shows that in the future it could be possible to produce artificial penises for replacement surgeries or phalloplasties
Phalloplasty
Phalloplasty refers to the construction of a penis or, sometimes, artificial modification of the penis by surgery, often for cosmetic purposes. It is also occasionally used to refer to penis enlargement....
.
Size
While results vary across studies, the consensus is that the average erect
Erection
Penile erection is a physiological phenomenon where the penis becomes enlarged and firm. Penile erection is the result of a complex interaction of psychological, neural, vascular and endocrine factors, and is usually, though not exclusively, associated with sexual arousal...
human penis is approximately 12.9–15 cm (5.1–5.9 in) in length with 95% of adult males falling within the interval (10.7 cm, 19.1 cm) or (4.23 in, 7.53 in). The typical girth or circumference
Circumference
The circumference is the distance around a closed curve. Circumference is a special perimeter.-Circumference of a circle:The circumference of a circle is the length around it....
is approximately 12.3 cm (4.84 in) when fully erect. The average
Arithmetic mean
In mathematics and statistics, the arithmetic mean, often referred to as simply the mean or average when the context is clear, is a method to derive the central tendency of a sample space...
penis size is slightly larger than the median
Median
In probability theory and statistics, a median is described as the numerical value separating the higher half of a sample, a population, or a probability distribution, from the lower half. The median of a finite list of numbers can be found by arranging all the observations from lowest value to...
size (i.e., most penises are below average in size).
A research project, summarizing dozens of published studies conducted by physicians of different nationalities, shows that, worldwide, erect-penis size averages vary between 9.6 and 16 cm (3.8 and 6.3 in). It has been suggested that this difference is caused not only by genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
but also by environmental factors such as culture
Culture
Culture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
, diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
, chemical/pollution exposure, etc. Endocrine disruption resulting from chemical exposure has been linked to genital deformation in both sexes (among many other problems).
Circumcised men are on average 8 millimeters shorter in terms of erect length compared to their intact counterparts.
The longest officially documented human penis was found by Doctor Robert Latou Dickinson
Robert Latou Dickinson
Robert Latou Dickinson was an American obstetrician and gynecologist, surgeon, maternal health educator, artist, sculptor and medical illustrator, and research scientist.-Life:...
. It was 34.3 cm (13.5 in) long and 15.9 cm (6.26 in) around.
Cultural aspects
- Aesthetic, e.g., Body modificationBody modificationBody modification is the deliberate altering of the human body for any non-medical reason, such as aesthetics, sexual enhancement, a rite of passage, religious reasons, to display group membership or affiliation, to create body art, shock value, or self expression...
- In humor, considered indecent or completely tabooTabooA taboo is a strong social prohibition relating to any area of human activity or social custom that is sacred and or forbidden based on moral judgment, religious beliefs and or scientific consensus. Breaking the taboo is usually considered objectionable or abhorrent by society...
in various cultures - Religious veneration, see St. Priapus ChurchSt. Priapus ChurchSt. Priapus Church is a North American religion founded in the 1980s that centres on the worship of the phallus.St. Priapus Church was founded in Montreal, Quebec, by D. F. Cassidy and has found a following mainly among homosexual men in Canada and the United States...