350px|Ilustrasion ti anatomia ti sistema a panagpaadu ti lalaki a tao.]]
[[File:Permanently retracted foreskin.jpg|thumb|220px|Buto]]
Ti buto ket maysa nga organo a reproduktibo a teknikal nga intromitente nga organo, ken para kadagiti plasental a mammal, ket agservi pay kas external nga organo ti panagisbo. Heneral a masarakan ti buto kadagiti mammal ken reptilia.▼
Ti buto ket maysa nga organo a reproduktibo a teknikal nga intromitente nga organo, ken para kadagiti plasental a mammal, ket
nga organo ti panagisbo.
a masarakan ti buto kadagiti mammal ken reptilia.
== Ti buto ti tao ==
[[File:Erection development animated.ogv|right|thumb|Ti buto ti laking buto iti tao ayon nga kasalsalan.]]
=== Estruktura ===
Buklen ti tallo a columna ti
tisiu ti buto ti tao: dua a corpora cavernosa ti agkaabay iti batog a dorsal ken maysa a corpus spongiosum ti adda iti baetanda iti batog a ventral.
Ti dakdakkel ken ugis-bombilia nga ungto ti corpus spongiosum ti mangbukel iti lukdit wenno lusngi wenno glanse ti buto, a mangsupsuportar iti supotlalat wenno prepusio, maysa a nalukay a kulpi ti kudil a kadagiti nataengan ket mabalin a malislis tapno a maexposar ti lusngi. Ti sirok ti buto a nakakabitan ti prepusio ket maawagan a freno wenno frenulo.
=== Pubertad ===
Iti iseserrek iti pubertad, mangrugi nga agdevelop dagiti bukelbukel ken dumakkelen dagiti mabagbagi. Mangrugi a dumakkel ti buto iti baet dagiti tawen kas kasapa ti 10 ken kas kaladaw ti 15. Usual nga agleppas ti idadakkel iti edad 18-21. Bayat ti proseso, agtubo dagiti urmot iti aglawlaw ti buto.
Sexual a Kaibatugan ===
Kaibatugan ti lusngi ti lalaki ti mutil ti manimani ti babai; kaibatugan ti corpora cavernosa ti bagi ti manimani; kaibatugan ti corpus spongiosum ti vestibular a bulbo iti baba ti labia minora; kaibatugan ti butillog wenno eskroto ti labia minora ken labia mayora; ken kaibatugan ti prepusio ti akkub ti manimani. Awan rafe dagiti babbai, ta idiay, saan a konektado dagiti dua a gudua.
=== Panagtangar ===
Ti panagtangar ket ti panagtangken ken panagngato ti buto a mapasamak iti panaguttog,a kas preparsyon no kayat ti lalaki ti umiyot, no pay mabalin a mapasamak daytoy kadagiti situasion a di-
sexual. Ti kangrunaan a fisiolohikal a mekanismo a mangigapu iti panagtangar ket ti autonomiko a dilasion dagiti arteria a mangitultulod iti dara iti buto. Palubusan daytoy ti ad-adu a dara a mangpunno kadagiti tallo a maraespongha a kamara iti buto nga agbanag iti panagatiddog ken panagtangken daytoy. Ti napnon nga erektil a tisiu itan ket agtalmeg ken mangpetpet kadagiti vena a mangiruar iti dara manipud iti buto. Ad-adu itan ti sumrek a dara ngem iti rumuar iti buto agingga a madanon ti equilibrio no sadino ket agpada ti kaadu ti dara a sumrek ken rumuar kadagiti dilatado nga arteria ken napetpetan a vena; magun-od kadaytoy nga equilibrio ti maysa a konstante a rukod ti panagtangar.
Fasilitaren ti panagtangar ti sexual a pannakinaig no pay saan a nasisita kadagiti dadduma pay a
sexual nga aktividad.
=== Panagparuar ===
Ti panagparuar ket ti panagipugso iti kapsit manipud iti buto, ken usual a kakuyog ti orgasmo. Maysa a serie dagiti
muscular a kontraksion ti mangiparuar iti semilia nga aglaon kadagiti gameto ti lalaki a maawagan iti selula nga esperme wenno spermatozoa manipud iti buto (mapan iti uki, no para iti intension ti panagpaadu babaen ti sexual a pannakinaig). Masansan a resulta daytoy ti sexual nga estimulasion, a mabalin a karaman ti estimulasion ti prostrata. Daytoy ket raro a gapu ti sakit a prostratiko. Mabalin pay a mapasamak ti panagparuar bayat ti panagturog (emision a nokturnal). Aneyakulasion ket ti kondision no sadino ket madi makapagparuar.
Ti panagparuar ket addaan iti dua a paset: emision ken ti mismo a panagparuar. Ti paset nga emision ti
eyakulatorio a reflexo ken kontrolado ti simpatetiko a sistema ti nervios, anta ti paset ti panagparuar ken kontrilado ti nadorian wenno espinal a reflexo iti level dagiti nadorian a nervios nga S2-4 babaen ti pudendal a nervios. Sarunoen ti periodo a refraktorio ti panagparuar, ken pasakbayan met daytoy sexual nga estimulasion.
=== Kugit ===
Ti kagagangayan a
forma ti alterasion iti mabagbagi ket ti kugit wenno sirkumsision: ti pannakaikkat iti parte wenno ti sibubukel a prepusio para kadagiti nadumaduma a kultural, relihioso, ken nararraro, medikal a rason.
=== Rukod ===
No pay sabasabali dagiti resulta dagiti panagadal, ti konsenso ket ti
regular a rukod ti nakatangar a buto ti tao ket 5.1-5.9 pulgada a kaatiddog nga addaan iti 95% nga interval ti konfidensa ti 4.23-7.53 pulgada. Ti tipikal a kabuntog ti agarup 4.84 pulgada no todon ti panagtangar.
==The human penis==
The human penis differs from those of some other mammals. It has no [[baculum]], or '''erectile bone'''; instead it relies entirely on engorgement with blood to reach its erect state. It cannot be withdrawn into the groin, and is larger than average in proportion to body mass.
The human penis is made up of three columns of erectile [[biological tissue|tissue]]:
* the two [[corpora cavernosa]] (singular: ''corpus cavernosum'') and
* one [[corpus spongiosum]]
The corpus spongiosum lies on the underside (known also as the [[anatomical position|ventral side]]) of the penis; the two corpora cavernosa lie next to each other on the upper side ([[anatomical position|dorsal side]]).
The end of the corpus spongiosum is enlarged and cone-shaped and forms the [[glans penis]]. The glans 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 [[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 both a passage for [[urine]] and for the [[ejaculation]] of [[semen]]. Sperm is 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 under side of the penis, running from the meatus (opening of the urethra) across the scrotum to the [[perineum]] (area between scrotum and anus).
=== Relation to female genitals ===
The [[Glans penis|glans]] of the penis is [[homologous]] to the [[clitoris|clitoral glans]], the corpora cavernosa are homologous to the body of the [[clitoris]], the corpus spongiosum is homologous to the [[vestibular bulb]]s beneath the labia minora, and the scrotum is homologous to the [[labia minora]], [[labia majora]] and [[clitoral hood]]. The raphe does not exist in females, because there the two halves are not connected.
=== Erection ===
[[Erection]] is the stiffening and rising of the penis which occurs in the [[sexual arousal|sexually aroused]] male, 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 the penis than leaves until an equilibrium is reached (equal volume of blood flowing into the dilated arteries and out of the constricted veins). A constant erectile size is achieved at equilibrium.
Inability to attain a satisfactory erection is known medically as [[erectile dysfunction]], or ED in short. A drug against this condition, ''[[sildenafil]] citrate'' (marketed as [[Viagra]]®) works by [[vasodilation]].
Erection facilitates [[sexual intercourse]] though it is not essential for some other [[sexual activities]]. 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, depending on the tension of the suspensory ligament that holds it in position. Stiffness of erectile angle also varies.
''See main article [[Human penis size]]''
As a general rule, an [[animal]]'s penis is proportional to its body size, but this varies greatly between [[species]] — even between closely related species. For example, an adult [[gorilla]]'s erect penis is about 1.5 [[inch|inches]] (4 [[cm]]) in length; an adult [[chimpanzee]], significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. The chimpanzee has the second largest penis size among the [[hominidae|great apes]]: in comparison, the [[human]] penis is by far the largest of all the [[primate]]s, both proportional to body size and in absolute terms; one study has found that the average human penis is 5 inches (12.7 cm)in length when fully engorged with blood during arousal.
As with any other bodily attribute, the length and girth of the penis is highly variable between individuals of the same species. In many animals, especially [[mammal]]s, the size of a flaccid penis is much smaller than its size when erect. In humans and some other species, flaccid vs. erect penis size varies greatly between individuals, such that penis size when flaccid is not a reliable predictor of size when erect.
Except for extreme cases at either end of the size spectrum, penis size does not correspond strongly to reproductive ability in almost any species.
Depending on temperature, a flaccid (not erect) penis of average size can withdraw almost completely within the body. During erection the penis will return to its normal (erect) size.
* [[Hirsuties papillaris genitalis|Pearly penile papules]] are raised bumps of somewhat paler colour around the base of the glans and are normal. See [[sidebar]] picture and picture at article.
* [[Fordyce's spots]] are small, raised, yellowish-white spots 1-2mm in diameter that may appear on the penis, as well as the inner surface and [[vermilion border]] of the lips of the face, and are normal.
* ''Sebaceous prominences'' are raised bumps similar to Fordyce's spots on the shaft of the penis, located at the [[sebaceous gland]]s and are normal.
* [[Phimosis]], an inability to retract the foreskin fully, is harmless in infants and pre-pubescent males, occurring in about 8 percent of boys at age 10.
===Disorders affecting the penis===
[[Oedema]] (swelling) of the foreskin can result from sexual activity, including [[masturbation]]. It appears worrying but so long as the foreskin is in its normal position and blood flow is present it's harmless. See ''paraphimosis'' for situations where the foreskin can't be moved to its normal position or the swelling persists. If the condition recurrs regularly, medical advice should be obtained, since it can be a symptom of conditions such as chronic heart disease. (''[http://www.links.net/vita/corp/catdick/ description of a case resulting from sexual activity, with pictures]'')
''Pathological Phimosis''--where a non-retracting foreskin is accompanied by pain or physiological distress, or affects physical hygiene, requires treatment which can be surgical or non-surgical depending on the seriousness of the condition. See [[Phimosis]] for more details.
[[Paraphimosis]] is an inability to move the foreskin forward over the glans. It can result from fluid trapped in a foreskin which is left retracted, perhaps following a medical procedure, or accumulation of fluid in the foreskin because of friction during vigorous sexual activity. Applying pressure to compress the glans, then moving the foreskin to its normal position is the initial procedure to follow, perhaps with the assistance of a lubricant. Placing the penis in normal granulated sugar can reduce the swelling via osmosis. If the condition persists for more than several hours or there's a sign of lack of blood flow, a hard glans with no erection or an inability to urinate, it should be treated as a medical emergency.
In [[Peyronie's disease]], anomalous scar tissue grows in the soft tissue of the penis, causing curvature. Severe cases can benefit from surgical correction.
A [[thrombosis]] can occur during periods of frequent and prolonged sexual activity, especially [[fellatio]]. It is usually harmless and self-corrects within a few weeks.
[[Pudendal nerve entrapment]] 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 nerve]] can be damaged by narrow hard cycle seats and accidents.
[[Penile fracture]] can occur if the erect penis is bent excessively. A pop 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.[http://www.blackwell-synergy.com/links/doi/10.1046/j.1464-410X.1996.86420.x/abs/]
In [[diabetes]], [[peripheral neuropathy]] 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 dysfunction]], formerly known as ''impotence'', is the inability to have and maintain an erection sufficiently firm for satisfactory sexual performance. A wide variety of generally effective treatments are available. Diabetes is a leading cause, as is normal aging.
[[Priapism]] 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 gangrene, which may necessitate amputation.
====Developmental disorders of the penis====
[[Hypospadias]] is a [[developmental disorder]] where the [[meatus]] is positioned wrongly at birth. Hypospadias can also occur [[iatrogenic]]ally by the downward pressure of an indwelling urethral catheter.[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9554017] It is usually corrected by surgery.
A [[micropenis]] is a very small penis caused by developmental problems.
== Image ti Buto ==
File:Superficial dorsal vein of the penis (erect).png|Buto (bangon)
File:Superficial dorsal vein of the penis (flaccid).png|Buto (flaccid)