penis

陰茎 　 　

WordNet

1. the male organ of copulation (`member is a euphemism) (同)phallus, member
2. of or relating to the penis; "penile erection" (同)penial
3. a writing implement with a point from which ink flows
4. an enclosure for confining livestock
5. female swan

PrepTutorEJDIC

1. 陰茎,ペニス
2. 〈C〉(インクを用いる筆記具全体をさして)『ペン』;万年筆,ポールペン,フェルトペン;ペン先 / 〈U〉《the~》文筆,著述 / 〈C〉《単数形で》《文》文筆家 / 《気どって》…‘を'書く,著す(write)
3. 〈C〉(家畜などを入れる)『おり』 / 《集合的に》ありの中の動物 / 〈C〉(監禁・保護に使われる)囲い,幼児用遊びわく(playpen) / (囲い・ありなどに)…‘を'入れる,閉じ込める,監禁する《+『名』+[『up』]『in』+『名』》
4. 刑務所[penitentiaryの短縮形]

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/06/11 22:41:46」(JST)

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陰茎
ヒトの男性器の断面図
ラテン語	penis pene pen?
英語	Penis
器官	男性器
動脈	陰茎背動脈 陰茎深動脈 陰茎球動脈
静脈	浅陰茎静脈
神経	陰核背神経

陰茎（いんけい、英語:penis）は体内受精をする動物のオスにあって、身体から常時突出しているか、あるいは突出させることができる器官である。精子をメスの体内に直接送りこむ際に、これを雌の生殖器に挿入するのに用いられる性器（交接器）である。雄の生殖器、特に外性器のうちのひとつ。また、哺乳類では泌尿器を兼ね、睾丸の上部から突き出ている。

動物一般

体内受精する動物の多くが、精子を雌の体内に注入するため、雌の体内に差し入れることのできる管状の構造を発達させており、これが陰茎である。体内受精であっても、精包を受け渡すなど、交尾をしない型もあるので、体内受精する動物のすべてのオスが持っているわけではない。陰茎は、雄性生殖巣の出口に位置し、そこから突出するか、必要な場合に突き出すことができる。生殖巣の出口は肛門と共通であるか、あるいはそれに近い所にある例が多いため、陰茎もそこにある場合が多い（脊椎動物や昆虫類）が、例外もある。例えばミミズ類では体の前半、環帯より前の体節にあり、カタツムリなどでは体中央付近側面にある。

一つだけ持つ例も複数を持つ例もある。脊椎動物ではほ乳類や鳥類（あれば）やカメは一本、同じは虫類でもヘビやトカゲは一対である。無脊椎動物ではウズムシ類や昆虫は一本、ミミズ類は複数対を持つ。

陰茎を持つ動物では、雌にもそれに対応する構造が形成される例もあり、これを陰核と言う。

なお、線虫類では交尾の際に雌の体内に挿入する針状構造があるが、精子が内部を通り抜けるのではないので、陰茎とは言わず、「交尾針」と呼んでいる。

ヒトの陰茎

通常時のヒトの陰茎。1. 陰茎海綿体、2. 包皮、3. 陰茎亀頭、4. 外尿道口

ヒト陰茎の通常時（左）と勃起時（右）の変化。

哺乳類の陰茎には、尿道が中を通っているのが特徴である。尿道には、精子を含む精液と、尿との両方が流れる。したがって、陰茎は、性器であると同時に泌尿器の働きを持っている。尿道の途中には弁があり、尿と精液が交ざり合うことはない。陰茎は、性行為の際に海綿体が充血して勃起することで女性器（膣）に挿入可能な硬さを持つようになる。ヒトの陰茎には陰茎骨がない。

構造と機能

陰茎は、平時は左右の脚の間の前方に懸垂する柔軟な器官で、普段は排尿に用いられ、また性交時には勃起し、精液を射出する器官でもある。思春期に第二次性徴によって男性器の成長のTannerの第3段階より陰茎が長くやや太くなり（陰茎の増大から約1年後に陰毛が発生する）、第4段階で長く太くなり、亀頭が発達する。そして第5段階で成人型となる。形状・長さ・太さ・色合いなどには個人差がある。完全にまっすぐな陰茎はまれであり、大抵上下左右いずれかの方向に曲がっている。大きく曲がっていても性交に支障はまずないが、45°を超えるようだと支障を来たし手術で矯正することがある。ペイロニー病も参照。

海綿体

陰茎の内部には、左右1対の陰茎海綿体と、その下側を通るある尿道海綿体の、計3本の海綿体が通っている。 2本の陰茎海綿体は根部で左右に分かれ、陰茎脚を形成しており、尿道海綿体は中に尿道が通っている。 海綿体は、体内の会陰部から陰茎の先端まで続いており、陰茎の大半を構成している。陰茎の先端まで続いているのは尿道海綿体であり、根側では尿道球部を、亀頭を形作っている。海綿体は白膜と呼ばれる強靱な膜で包まれ、それを更に陰茎筋膜、浅陰茎筋膜が包み、その外が皮膚となっている。

海綿体の内部は、蛇行する静脈洞が密集してスポンジ状になっており、副交感神経を通じて、陰茎深動脈からの血流が調節されている。性的興奮やその他の生理現象により、静脈洞への血流が多くなり、海綿体は血液で満たされて膨張して硬くなる。また、それと同時に海綿体表層部の導出静脈が圧迫・閉塞され、海綿体からの血液の流出が阻害される。これにより、陰茎全体も膨張して硬く変化する。これを陰茎の勃起と呼ぶ。勃起時に最も硬くなるのは陰茎海綿体であり、精液通路（尿道径）の確保のため、尿道海綿体は比較的柔らかい。

亀頭

亀頭（きとう）とは、陰茎の先端部分のくびれ（亀頭冠）から先の太さが違う部分をいう。尿道海綿体が陰茎の先端で太くなっており、皮膚のすぐ内側にまで存在している。亀頭部の皮膚はそれ以外よりも薄く、尿道海綿体に癒合している。亀頭の皮膚、皮下には、感覚受容器が発達しており、性行為の際の摩擦に特に敏感である。亀頭は前述通り、男性器の成長のTannerの第4段階より発育する。

亀頭の形状にも意味があり、前後運動の際、膣内に残された（他人 = ほかのオスや自身の）古い精液を掻き出す働きを持つ。ゴードン・ギャラップ博士による人工性器とコーンスターチを使った実験では、くびれのないものの35%に対し、くびれたものでは90%以上を排出している。。

包皮

詳細は「陰茎包皮」を参照

亀頭以外の陰茎の皮膚は、陰茎内部の組織と癒合しておらず、容易に前後に移動することができる。これにより性交の際の前後運動を円滑に行うことができる。この皮膚を「包皮（ほうひ）」と呼ぶ。 包皮には体毛は見られず、また亀頭の近辺の包皮には皮脂腺が多く、これが恥垢となる。 小児の場合、亀頭は包皮に覆われているのが生理的に普通である。成長後も覆われたままで亀頭が露出しないものを「包茎（ほうけい）」と呼ぶ。

動物（哺乳類）の多くでは、亀頭部分を保護する目的から、包茎ないし表皮の下に埋もれている事が常態で、勃起時にのみ突出する。シロナガスクジラの陰茎は最大で約2mの長さを持つが、これは通常の遊泳時にはS字型に表皮下に収納されており、外部に露出していない。

尿道

尿道海綿体を通る尿道は、亀頭の下側を通り、陰茎の先端に達し、そこで体外とつながる（外尿道口）。尿道は骨盤内部で膀胱に接続されている。膀胱にたまっている尿は、尿道を通り、陰茎の先端から体外へ排泄される。

一方、精子の通り道は、精管の端の射精管が尿道に、膀胱を出たばかりの場所で接続されており、ここで尿道に合流する。この部位の尿道は、前立腺の中を貫通している。前立腺は、もうひとつの分泌腺である精嚢と同様、精液の成分のほとんどを分泌する腺で、尿道を通る際に分泌液が精子と混ぜ合わされ、受精に適したpHと粘度になった後、体外に射出される。

尿の排泄は、膀胱の壁の筋の収縮によって起こる。精液の射出は、射精管、前立腺の壁の筋の収縮によって起こる。いずれも、これらを下腹部に力を入れて我慢する際には、陰茎よりも上流（内部）に相当する部位（尿生殖隔膜部）の尿道にある尿道括約筋を収縮させることで行われる。

勃起時には尿道が狭くなり尿の排泄が、不可能ではないにせよ困難となる。しかし射精時には尿道括約筋の働きにより尿の排泄が不可能となるばかりでなく、尿意も感じなくなり、尿道は精液の専用通路に切り替わる。性交時に膣内に尿が漏れることがないのは、このような理由によるものである。

陰茎のサイズ

詳細は「ヒトの陰茎のサイズ」を参照

ヒトの陰茎の大きさは個人によって様々である。乳幼児の頃は2 - 3cm程、引き伸ばした大きさ（≒勃起時）は約4cm程度。思春期開始時には4cm弱、引き伸ばした大きさ（≒勃起時）は6cm程度で思春期を経て急速に発達し、 成人では、平常時8cm、勃起時は報告によるが9.5cm、12.7cmなどとされている。17歳くらいまでに成長が止まると考えられている。

陰茎の病症

勃起不全

詳細は「勃起不全」を参照

ドイツ語でインポテンツ（Impotenz;略してインポ）。近年ではED (Erectile Dysfunction) とも呼ばれる。陰茎の勃起は、副交感神経に依存しており、末梢神経障害、心因性、脊髄損傷などで十分な勃起が起きなくなることがある。この勃起機能の低下を「勃起不全」という。ストレスなどで一時的に陥ることもあり、また糖尿病など特定の病気によってや、年齢を重ねるに従い勃起不全となる率も高くなる（バイアグラを参照）。勃起不全は40〜70歳の男性における有病率は50％で，加齢により上昇する。。

包茎（真性包茎）

詳細は「包茎」、「割礼」、および「包茎手術」を参照

包皮を反転させて亀頭を露出させることが不可能な場合を、「包茎（ほうけい）」あるいは「真性包茎（しんせいほうけい）」と呼ぶ。包皮の一部が亀頭に癒着していることや、亀頭先端を覆う包皮が狭い（包皮輪狭窄が起こっている）ために亀頭を通過させられないことが原因で起こる。罹患率は0.6 - 3.7%、または15歳の男性で8.6%などと言われている。

包皮輪狭窄が起こっている包茎には、平常時には包皮を反転させられる場合があるが、その結果、包皮の狭い部分が陰茎を絞扼し、亀頭が鬱血し、包皮を亀頭に被せられなくなることがある。このような症状を、「嵌頓（かんとん）」ないしは「嵌頓包茎（かんとんほうけい）」と呼ぶ場合もある。この場合、鬱血している部分が壊死する恐れがあるため、速やかに医療機関で処置を受ける必要がある。

平常時に亀頭が包皮に覆われているものの、勃起時に自然と亀頭が露出する、または手で容易に包皮を剥いたり亀頭に被せたりすることができる場合は、「仮性包茎（かせいほうけい）」と呼ばれる。治療対象となるのは病理学上の真性包茎が診療対象である。したがって診療上は包茎といった場合は真性包茎のみをさし、公的医療保険の対象となる。割礼を行わない成人男性の大半はこのような通常時包皮をかぶった状態であるとされており、通常、勃起や性交や射精に支障はない。

包茎治療

詳細は「 包茎手術」を参照

包茎治療は包茎の治療には外用コルチコステロイドと緩やかな伸長が有効であるが、包皮の環状切除が必要となることもある。

包皮の環状切除は、勃起時に余る分の包皮を外科的に切除してしまい、亀頭を覆うことができないようにする包皮切除手術（包茎手術）である。成人型男性器（男性器の成長のTannerの第5段階）に達しても包皮が反転できるようにならず勃起時に陰茎に痛みを感じる場合、あるいは嵌頓状態になって戻らない場合には、外科的治療の対象となり、健康保険の適用対象となる。

その一方で、勃起の妨げとはならない場合や、成人型男性器に達する前（男性器の成長のTannerの第1-4段階の間）の治療や、単なるアンカット（俗に言う仮性包茎）の場合は、美容外科（美容整形）と同様に自由治療となり、健康保険は適用されない。

また、民間療法としては、思春期以降、アンカット（仮性包茎）ペニスを気にした男性が、故意に包皮を剥いたまま生活することで、いつしか常に包皮が反転した状態でとどまるようになることがあるとの俗説から、通信販売（インターネット上のサービスを含む）などでこのための器具・物品が販売されている様子も見られる。。

割礼は地域によって慣習的に行われているが、その意味においては根拠に基づいた医療にはよらず、もっぱら宗教などに基づく風習的な面が強く、『スポック博士の育児書』では住んでいる地域で周囲が慣習的に行っている場合にのみ、将来的な子供間の被差別（いわゆるいじめ）などを回避する意味合いから施術を勧めている程度である。特に発展途上国では不衛生な状態での包皮切除により重大な結果を招くことが多くあり、長年問題視されている。

アメリカでは新生児に対する包皮切除手術が盛んに行われていた時期があったものの、ヨーロッパとは違い、包皮の重要性を説く一部の学説を契機に、新生児への割礼を行わない例も見受けられる。また、新生児期に包皮を切除された者の中には、包皮を取り戻したいという意思を持つ者もいるため、包皮再生手術も行われている。詳しくは割礼を参照のこと。また新生児に対する包皮切除手術の結果として、将来的な陰茎の変形などのケースも多数あり、こういった手術を問題視する傾向もある。

尿路感染症

男性は、女性に比べて陰茎のぶんだけ尿道が長く（一般的に男性は十数 cmで、女性は4 cm前後である）、また肛門から外尿道口が離れているため、女性に比較して尿路感染症にかかりにくい。しかし、高齢になると、男性も前立腺肥大のため膀胱に尿が貯留する傾向となるため尿路感染症にかかりやすくなる。

陰茎折症（陰茎骨折）

詳細は「 陰茎折症」を参照

勃起状態の陰茎に無理な力が加わると、海綿体を包んでいる白膜（陰茎海綿体薄膜）などが断裂する事があり、これを陰茎折症と言う。

陰茎の文化

詳細は「ファルス (性)」を参照

陰茎の俗称

幼児語における俗称として「ちんちん（おちんちん）」「ちんぼこ（ぼこちん）」「ちんこ」「ちんぽ」「ぽこちん（ちんぽこ）」がある（カタカナ書きする事もある）。おちんちんの項を参照。その一方で成人男子の陰茎を指す隠語としては「マラ（摩羅）」「竿（肉竿）」「肉棒」「ソーセージ」などがある。

民俗学関係では、女性器の外陰部を「女陰」と呼ぶのに対して、男性器の陰茎を「男根」「陽根」と呼んでいる。また、大きな膣口の女陰を「巨陰」と呼ぶのに対して、大きな男根を「巨根」と呼んでいる。

各地の男根信仰

神事

金山神社かなまら祭

日本の一部の神社では、五穀豊穣・子宝の神として、陰茎（ペニス）をご神体としているところがある。特に有名なのが、愛知県小牧市にある田縣神社（たがたじんじゃ）で、毎年3月15日に行われる「豊年祭」では、木でできた巨大な陰茎「大男茎型（おおおわせがた）」を神輿に乗せて練り歩くもので、当日は外国人も含め、多くの観客が訪れる。

静岡県賀茂郡東伊豆町稲取の「どんつく神社」には、木製の巨大な陰茎を載せた神輿が鎮座している。この神社の名前自体が、陰茎で「どん」と「突く（つく）」ということに由来するものである。毎年6月第1火 - 水曜日の2日間にかけて、「どんつく祭」が開催され、前述の神輿が温泉街を練り歩く。

福岡県田川郡添田町の深倉峡には奇岩「男魂岩」があり対岸の「女岩」との間がしめ縄で結ばれている。11月には「男魂祭」が開かれる。

他に男根信仰で有名な神社には、栃木県日光市と群馬県利根郡片品村の境にある金精神社、和歌山県西牟婁郡白浜町の歓喜神社、山口県長門市俵山の麻羅観音などがある。

パプアニューギニアでは主食であるヤムイモを人間の男と女に見立て、これで擬似的にセックスを表現する風習が存在している。

抽象的シンボルとして

ペニスは古来世界中で子孫繁栄やエネルギーのシンボルとしてさまざまな形で表現されてきた。

• 神戸市西区裸石神社

• 太陽公園

ヒト以外の陰茎

アイスランドペニス博物館に展示されているシロナガスクジラの陰茎

• 有袋類の多くは二股に分かれた陰茎を持っている。
• イルカは陰茎で物を掴めるという都市伝説があるが、それはある程度事実を反映しており、クジラやイルカは陰茎の先を性交を楽にするためにある程度曲げることができる。
• 哺乳類の最小の陰茎はヨーロッパトガリネズミの5mm、最大はシロナガスクジラで2mを越える（勃起時のサイズは交尾時にしか観察できないため測定は困難）。
• 鳥類で陰茎を持つのはダチョウ目、シギダチョウ目とカモ科である。これらの陰茎は哺乳類と構造が異なり、総排泄孔壁のリンパ液での勃起による。鳥類の中でもアフリカオタテガモは体長の半分近くになる、体の大きさに対し全脊椎動物中最長の陰茎を持つ。
• 爬虫類の有鱗目は2つの対になった半陰茎を持つ。
• 魚類の交尾鰭や交接器は鰭が変化して生じた。
• 昆虫の雄のペニスの相同器官は把握器 (aedeagus) と呼ばれる。

備考

アイスランドには「アイスランドペニス博物館」という規模こそ小さいが、世界でも類を見ない陰茎のみをテーマにした博物館がある。同館の標本・陰茎の剥製コレクションは、アイスランドの陸海に住むほとんどの哺乳類を網羅し、なかでも23種の鯨の陰茎を並べて示すという世界でも珍しい展示物がある。2011年1月初旬に死亡した男性のペニスが標本化され、ホモ・サピエンスのペニスが博物館の所蔵品に加わることになった。

出典

参考文献

• 国学院大学日本文化研究所　『日本の食とこころ - そのルーツと行方』　慶友社、2003年5月。ISBN 4874492339。

関連項目・文献

• 女性器
• フォアダイス
• 巨根
• ペニスバンド - 女性用の陰茎の代替物。
• おちんちん - 陰茎（男性外性器）の幼児語。
• 朝立ち (生理現象) - 寝起きに見られる陰茎の勃起現象。
• 陽物崇拝 - 古代においては、陰茎は繁栄の象徴と見なされることが多くあった。ファルス (性)を参照。
• 生殖器崇拝
• 金精神 - 陰茎の形をした御神体を祀った日本の神
• 割礼 - 幼少時に包皮を切除する儀式。アメリカなどの国やユダヤ教徒・イスラム教徒が衛生上、または宗教上の理由で行っている。
• 去勢
• 包茎手術商法 - 包茎手術に高額な金銭を請求するトラブル
• penis envy
• マルク・ボナール, ミシェル・シューマン, 藤田真利子 (訳) 『ペニスの文化史』 （作品社、2001年） ISBN 4878934263
• デビッド・フリードマン, 井上広美 (訳) 『ペニスの歴史 ― 男の神話の物語』 （原書房、2004年） ISBN 4562038527
• ペニス増大 - 陰茎の大きさを増大させる手法。

wiki en

[Wiki en表示]

This article is about penises of animals in general. For the human organ, see human penis.

"Penile" redirects here. For the community in Kentucky, see Penile, Louisville.

Penis of an Asian elephant.

A penis (plural penises or penes) is the primary sexual organ that male and hermaphrodite animals use to inseminate sexually receptive mates (usually females and hermaphrodites respectively) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do not bear a penis in every animal species, and in those species in which the male does bear a so-called penis, the penes in the various species are not necessarily homologous. For example, the penis of a mammal is at most analogous to the penis of a male insect or barnacle.

The term penis applies to many reproductive intromittent organs, but not to all; for example the intromittent organ of most cephalopoda is the hectocotylus, a specialised arm, and male spiders use their pedipalps. Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes.

In most species of animals in which there is an organ that might reasonably be described as a penis, it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the penis bears the distal part of the urethra, which discharges both urine during urination and semen during copulation as the occasion requires.

In different animals

See also category: Animal penises

Vertebrates

Birds

See also: Intromittent organ § Birds and Bird anatomy § Urogenital and Endocrine systems

Mallard pseudo-penis

Most male birds (e.g., roosters and turkeys) have a cloaca (also present on the female), but not a penis. Among bird species with a penis are paleognathes (tinamous and ratites), Anatidae (ducks, geese and swans), and a very few other species (including flamingoes and chickens). A bird penis is different in structure from mammal penises, being an erectile expansion of the cloacal wall and being erected by lymph, not blood. It is usually partially feathered and in some species features spines and brush-like filaments, and in flaccid state curls up inside the cloaca. The Argentine Blue-bill has the largest penis in relation to body size of all vertebrates; while usually about half the body size (20 cm), a specimen with a penis 42.5 cm long is documented.

While most male birds have no external genitalia, male waterfowl (Anatidae) have a phallus. Most birds mate with the males balancing on top of the females and touching cloacas in a “cloacal kiss”; this makes forceful insemination very difficult. The phallus that male waterfowl have evolved everts out of their bodies (in a clockwise coil) and aids in inseminating females without their cooperation. The male waterfowl evolution of a phallus to forcefully copulate with females has led to counteradaptations in females in the form of vaginal structures called dead end sacs and clockwise coils. These structures make it harder for males to achieve intromission. The clockwise coils are significant because the male phallus everts out of their body in a counter-clockwise spiral; therefore, a clockwise vaginal structure would impede forceful copulation. Studies have shown that the longer a male’s phallus is, the more elaborate the vaginal structures were.

The Lake Duck is notable for possessing, in relation to body length, the longest penis of all vertebrates; the penis, which is typically coiled up in flaccid state, can reach about the same length as the animal himself when fully erect, but more commonly is about half the bird's length. It is theorized that the remarkable size of their spiny penises with bristled tips may have evolved in response to competitive pressure in these highly promiscuous birds, removing sperm from previous matings in the manner of a bottle brush.

Male and female emus are similar in appearance, although the male's penis can become visible when it defecates.

The male tinamou has a corkscrew shaped penis, similar to those of the ratites and to the hemipenis of some reptiles. Females have a small phallic organ in the cloaca which becomes larger during the breeding season.

Mammals

Further information: Sexual reproduction in male mammals

As with any other bodily attribute, the length and girth of the penis can be highly variable between mammals of different species. In many mammals, the size of a flaccid penis is smaller than its erect size. In the realm of absolute size, the smallest vertebrate penis belongs to the common shrew (5 mm or 0.2 inches).

A bone called the baculum or os penis is present in most mammals but absent in humans, cattle and horses.

In mammals the penis is divided into three parts:

• Roots (crura): these begin at the caudal border of the pelvic ischial arch.
• Body: the part of the penis extending from the roots.
• Glans: the free end of the penis.

The internal structures of the penis consist mainly of cavernous, erectile tissue, which is a collection of blood sinusoids separated by sheets of connective tissue (trabeculae). Some mammals have a lot of erectile tissue relative to connective tissue, for example horses. Because of this a horse's penis can enlarge more than a bull's penis. The urethra is on the ventral side of the body of the penis. As a general rule, a mammal's penis is proportional to its body size, but this varies greatly between species – even between closely related ones. For example, an adult gorilla's erect penis is about 4 cm (1.5 in) in length; an adult chimpanzee, significantly smaller (in body size) than a gorilla, has a penis size about double that of the gorilla. In comparison, the human penis is larger than that of any other primate, both in proportion to body size and in absolute terms.

Hoofed mammals

When mating, the tip of a male pronghorn's penis is often the first part to touch the female pronghorn. The pronghorn's penis is about 5 inches long, and is shaped like an ice pick. The front of a pronghorn's glans penis is relatively flat, while the back is relatively thick. The male pronghorn usually ejaculates immediately after intromission.

The penis of a dromedary camel is covered by a triangular penile sheath opening backwards, and is about 60 cm (24 in) long. The camelmen often aid the male to enter his penis into the female's vulva, though the male is considered able to do it on his own. Copulation time ranges from 7–35 minutes, averaging 11–15 minutes.

Bulls have a fibro-elastic penis. Given the small amount of erectile tissue, there is little enlargement after erection. The penis is quite rigid when non-erect, and becomes even more rigid during erection. Protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure.

Bulls, rams and boars have an S-shaped penis with a sigmoid flexure which straightens out during erection. A boar's penis, which rotates rhythmically during copulation, is about 18 inches long, and ejaculates about a pint of semen. Stallions have a vascular penis. When non-erect, it is quite flaccid and contained within the prepuce (foreskin, or sheath).

Tapirs have exceptionally long penises relative to their body size. The glans of the Malayan tapir resembles a mushroom, and is similar to the glans of the horse.

Deer

Main article: Deer penis

A stag's penis forms an S-shaped curve when it is not erect, and is retracted into its sheath by the retractor penis muscle. Some deer species spray urine on their bodies by urinating from an erect penis. One type of scent-marking behavior in elk is known as "thrash-urination, which typically involves palpitation of the erect penis. A male elk's urethra points upward so that urine is sprayed almost at a right angle to the penis. A sambar stag will mark himself by spraying urine directly in the face with a highly mobile penis, which is often erect during its rutting activities. Red deer stags often have erect penises during combat.

Carnivorans

See also: Carnivora § Reproductive system

All members of Carnivora (except hyenas) have a baculum. Canine penises have a structure at the base called the bulbus glandis.

During copulation, the spotted hyena inserts his penis through the female's pseudo-penis instead of directly through the vagina, which is blocked by the false scrotum and testes. Once the female retracts her clitoris, the male enters the female by sliding beneath her, an operation facilitated by the penis' upward angle. The pseudo-penis closely resembles the male hyena's penis, but can be distinguished from the males' genitalia by its greater thickness and more rounded glans. In male spotted hyenas, as well as females, the base of the glans is covered with penile spines.

Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Male lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.

The male fossa has an unusually long penis and baculum (penis bone), reaching to between his front legs when erect, with an average thickness of 20 mm (0.79 in). The glans extends about halfway down the shaft and is spiny except at the tip. In comparison, the glans of felids is short and spiny, while that of viverrids is smooth and long. Fossa mating includes a copulatory tie, which may be enforced by the male's spiny penis. This unusually lengthy mating is due to the physical nature of the male's erect penis, which has backwards-pointing spines along most of its length. The male fossa has scent glands near the penis, with the penile glands emitting a strong odor.

The beech marten's penis is larger than the pine marten's, with the bacula of young beech martens often outsizing those of old pine martens.

Raccoons have penis bones which bend at a 90 degree angle at the tip. The extrusibility of a raccoon's penis can be used to distinguish mature males from immature males.

Male walruses possess large penis bones, up to 63 cm (25 in) in length, the largest of any land mammal, both in absolute size and relative to body size.

The adult male American mink's penis is 2.2 in (5.6 cm) long, and is covered by a sheath. The baculum is well-developed, being triangular in cross section and curved at the tip.

Cetaceans

Penises of minke whales on display at the Icelandic Phallological Museum

Cetaceans have fibroelastic penises, similar to those of Artiodactyla. The tip of the cetacean penis, which tapers toward the end, is called the pars intrapraeputialis or terminal cone. The blue whale has the largest penis of any organism on the planet, typically measuring 8–10 feet. Accurate measurements of the blue whale are difficult to take because the whale's erect length can only be observed during mating. The penis on a right whale can be up to 2.7 m (8.9 ft) – the testes, at up to 2 m (6.6 ft) in length, 78 cm (2.56 ft) in diameter, and weighing up to 525 lb (238 kg), are also by far the largest of any animal on Earth. Dolphins' reproductive organs are located on the underside of the body. Male dolphins have two slits, one concealing the penis and one further behind for the anus. On at least one occasion, a dolphin was known to tow bathers through the water by hooking his large penis around them. Between male bottlenose dolphins, homosexual behaviour includes rubbing of genitals against each other, which sometimes leads to the males swimming belly to belly, inserting the penis in the other's genital slit and sometimes anus.

Bats

Males of Racey's pipistrelle bat have a long, straight penis with a notch between the shaft and the narrow, egg-shaped glans penis. Near the top, the penis is haired, but the base is almost naked. In the baculum (penis bone), the shaft is long and narrow and slightly curved. The length of the penis and baculum distinguish P. raceyi from all comparably sized African and Malagasy vespertilionids. P. endoi, P. paterculus, and P. abramus have more similar bacula, but that of P. abramus is more curved, the shaft and the tip are more robust in P. paterculus, and the proximal (near) end is more robust in P. endoi. In males, penis length is 9.6 to 11.8 mm (0.38 to 0.46 in) and baculum length is 8.8 to 10.0 mm (0.35 to 0.39 in).

Copulation by male greater short-nosed fruit bats is dorsoventral and the females lick the shaft or the base of the male's penis, but not the glans which has already penetrated the vagina. While the females do this, the penis is not withdrawn and research has shown a positive relationship between length of the time that the penis is licked and the duration of copulation. Post copulation genital grooming has also been observed.

Rodents

The glans penis of the marsh rice rat is long and robust, averaging 7.3 mm (0.29 in) long and 4.6 mm (0.18 in) broad, and the baculum (penis bone) is 6.6 mm (0.26 in) long. As is characteristic of Sigmodontinae, the marsh rice rat has a complex penis, with the distal (far) end of the baculum ending in three digits. The central digit is notably larger than those at the sides. The outer surface of the penis is mostly covered by small spines, but there is a broad band of nonspinous tissue. The papilla (nipple-like projection) on the dorsal (upper) side of the penis is covered with small spines, a character the marsh rice rat shares only with Oligoryzomys and Oryzomys couesi among oryzomyines examined. On the urethral process, located in the crater at the end of the penis, a fleshy process (the subapical lobule) is present; it is absent in all other oryzomyines with studied penes except O. couesi and Holochilus brasiliensis. The baculum is deeper than it is wide.

In Transandinomys talamancae, the outer surface of the penis is mostly covered by small spines, but there is a broad band of nonspinous tissue.

Some features of the accessory glands in the male genital region vary among oryzomyines. In Transandinomys talamancae, a single pair of preputial glands is present at the penis. As is usual for sigmodontines, there are two pairs of ventral prostate glands and a single pair of anterior and dorsal prostate glands. Part of the end of the vesicular gland is irregularly folded, not smooth as in most oryzomyines.

In Pseudorhyzomys, the baculum (penis bone) displays large protuberances at the sides. In the cartilaginous part of the baculum, the central digit is smaller than those at the sides.

In Drymoreomys, there are three digits at the tip of the penis, of which the central one is the largest. The two lateral digits are not supported by mounds of the baculum (penis bone). There is only one spine on the papilla (nipple-like projection) on the upper side of the penis. On the urethral process, located in the crater at the end of the penis, a fleshy process at the side, the lateral lobule, is present. The preputial glands (glands in front of the genitals) are large. The lack of lateral bacular mounds, presence of a lateral lobule, and size of the preputial glands are all unique traits among the oryzomyines.

In Thomasomys ucucha the glans penis is rounded, short, and small and is superficially divided into left and right halves by a trough at the top and a ridge at the bottom. Most of the glans is covered with spines, except for an area near the tip.

The glans penis of a male cape ground squirrel is large with a prominent baculum.

Unlike the penises of other squirrel species, a red squirrel's penis is long, thin, and narrow, without a prominent baculum.

Winkelmann's mouse can easily be distinguished from its close relatives by the shape of its penis, which has a partially corrugated glans.

The foreskin of a capybara is attached to the anus in an unusual way, forming an anogenital invagination.

Primates

It has been postulated that the shape of the human penis may have been selected by sperm competition. The shape could have favored displacement of seminal fluids implanted within the female reproductive tract by rival males: the thrusting action which occurs during sexual intercourse can mechanically remove seminal fluid out of the cervix area from a previous mating.

Male galago species possess very distinctive penile morphology that can be used to classify species. In O. crassicaudatus, the penis is on average 20 mm in length and increases in width towards the distal tip. The baculum clearly protrudes from the end. The glans and shaft are covered in single keratinized spines that point towards the body.

The northern greater galago penis is on average 18 mm in length and width of shaft is even from body to bottom of tip. The baculum is clearly visible at the tip. The glans terminates with a characteristic set of curves which does not occur in any other species. The surface is spined with doubled headed or even tridentate spines pointing towards the body. They are less densely packed than in Otolemur crassicaudatus.

The penile morphology of some types of prosimians has provided information about their taxonomy. The penis of the ring-tailed lemur is nearly cylindrical in shape and is covered in small spines, as well as having two pairs of larger spines on both sides. Males have a relatively small baculum (penis bone) compared to their size. The scrotum, penis, and prepuce are usually coated with a foul-smelling secretion.

The adult male of each vervet monkey species has a pale blue scrotum and a red penis, and male proboscis monkeys have a red penis with a black scrotum.

Male baboons and squirrel monkeys sometimes gesture with an erect penis as both a warning of impeding danger and a threat to predators. Genital display among male squirrel monkeys is an important social signal in relation to group hierarchy; it is derived from sexual behavior but is used for social communication. It involves the animal spreading his thighs and having an erect penis.

Humans

Main article: Human penis

Penis of a male human

The human penis is an external sex organ of male humans. It is a reproductive, intromittent organ that additionally serves as the urinal duct. The main parts are the root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the crus of penis, one on either side of the bulb; the body of the penis (corpus); and the epithelium of the penis consists of the shaft skin, the foreskin, and the preputial mucosa on the inside of the foreskin and covering the glans penis.

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 urethra, which is the last part of the urinary tract, traverses the corpus spongiosum, and its opening, known as the meatus /miːˈeɪtəs/, lies on the tip of the glans penis. It is a passage both for urine and for the ejaculation of semen.

In males, the expulsion of urine from the body is done through the penis. The urethra drains the bladder through the prostate gland where it is joined by the ejaculatory duct, and then onward to the penis.

An erection is the stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations. Ejaculation is the ejecting of semen 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.

The most common form of genital alteration is circumcision: removal of part or all of the foreskin for various cultural, religious, and more rarely medical reasons. There is controversy surrounding circumcision.

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 10.7–19.1 cm (4.2–7.5 in). Neither patient age nor size of the flaccid penis accurately predicted erectile length.

Other mammals

The penis of the bush hyrax is complex and distinct from that of the other hyrax genera. It has a short, thin appendage within a cup-like glans penis and measures greater than 6 cm when erect. Additionally, it has been observed that the bush hyrax also has a greater distance between the anus and preputial opening in comparison to other hyraxes.

An adult elephant has the largest penis of any land animal. An elephant's penis can reach a length of 100 cm (39 in) and a diameter of 16 cm (6 in) at the base. It is S-shaped when fully erect and has a Y-shaped orifice. During musth, a male elephant may urinate with his penis still in the sheath, which causes the urine to spray on the hind legs. An elephant's penis is very mobile, being able to move independently of the male's pelvis, and the penis curves forward and upward prior to mounting another elephant.

In giant anteaters, the (retracted) penis and testes are located internally between the rectum and urinary bladder.

When the male armadillo Chaetophractus villosus is sexually aroused, species determination is easier. Its penis can be as long as 35 mm, and usually remains completely withdrawn inside a skin receptacle. Scientists conducting studies on the C. villosus penis muscles revealed this species' very long penis exhibits variability. During its waking hours, it remains hidden beneath a skin receptacle, until it becomes erect and it projects outside in a rostral direction. During its slow wave sleep phase, penile protrusion makes some very complex movements. The penis during this phase is not erect, but remains outside of its receptacle. During paradoxical sleep, no erections occur, and the penile muscles share the characteristics of the rest of the body.

Most marsupials, except for the two largest species of kangaroos, have a bifurcated penis, separated into two columns, so that the penis has two ends corresponding to the females' two vaginas.

Male echidnas have a four-headed penis. During mating, the heads on one side "shut down" and do not grow in size; the other two are used to release semen into the female's two-branched reproductive tract. The heads used are swapped each time the mammal copulates. When not in use, the penis is retracted inside a preputial sac in the cloaca. The male echidna's penis is 7 centimeters long when erect, and its shaft is covered with penile spines. The male short-beaked echidna has a highly unusual penis with four knobs on the tip, which is nearly a quarter of his body length when erect. Each side of the bilaterally symmetrical, rosette-like, four-headed penis [similar to that of reptiles and 7 centimetres (2.8 in) in length] is used alternately, with the other half being shut down between ejaculations.

Other vertebrates

See also: Intromittent organ § Vertebrata

Male turtles and crocodiles have a penis, while male specimens of the reptile order Squamata have two paired organs called hemipenes. Tuataras must use their cloacae for reproduction.

In some fishes, the gonopodium, andropodium, and claspers are intromittent organs (to introduce sperm into the female) developed from modified fins.

Invertebrates

Main article: Intromittent organ § Invertebrates

Arthropods

The spine-covered penis of Callosobruchus analis, a Bean weevil.

The record for the largest penis to body size ratio is held by the barnacle. The barnacle's penis can grow to up to forty times its own body length. This enables them to reach the nearest female.

A number of invertebrate species have independently evolved the mating technique of traumatic insemination where the penis penetrates the female's abdomen and deposits sperm in the wound it produces. This has been most fully studied in bed bugs.

Insects

In male insects, the structure analogous to a penis is known as aedeagus. The male copulatory organ of various lower invertebrate animals is often called the cirrus.

The lesser water boatman's mating call, generated by rubbing the penis against the abdomen, is the loudest sound, relative to body size, in the animal kingdom.

In 2010, entomologist Charles Linehard described Neotrogla, a new genus of barkflies. Species of this genus have sex-reversed genitalia. Females have penis-like organs called gynosomes that are inserted into vagina-like openings of males during mating. In 2014, a detailed study of the insects reprodutive habits led by Kazunori Yoshizawae confirmed that the organ functions similar to a penis – for example, it swells during sexual intercourse – and is used to extract sperm from the male.

Mollusks

The penis in most male Coleoid cephalopods is a long and muscular end of the gonoduct used to transfer spermatophores to a modified arm called a hectocotylus. That, in turn, is used to transfer the spermatophores to the female. In species where the hectocotylus is missing, the penis is long and able to extend beyond the mantle cavity and transfers the spermatophores directly to the female. Deep water squid have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessile barnacles Penis elongation in Onykia ingens may result in a penis that is as long as the mantle, head and arms combined. Giant squid of the genus Architeuthis are unusual in that they possess both a large penis and modified arm tips, although it is uncertain whether the latter are used for spermatophore transfer.

Etymology

The word "penis" is taken from the Latin word for "tail." Some derive that from Indo-European *pesnis, and the Greek word πέος = "penis" from Indo-European *pesos. Prior to the adoption of the Latin word in English the penis was referred to as a "yard". The Oxford English Dictionary cites an example of the word yard used in this sense from 1379, and notes that in his Physical Dictionary of 1684, Steven Blankaart defined the word penis as "the Yard, made up of two nervous Bodies, the Channel, Nut, Skin, and Fore-skin, etc."

As with nearly any aspect of the body involved in sexual or excretory functions, the penis is the subject of many slang words and euphemisms for it, a particularly common and enduring one being "cock". See WikiSaurus:penis for a list of alternative words for penis.

The Latin word "phallus" (from Greek φαλλος) is sometimes used to describe the penis, although "phallus" originally was used to describe representations, pictorial or carved, of the penis.

Pizzle, an archaic English word for penis, of Low German or Dutch origin, is now used to denote the penis of a non-human animal.

The adjectival form of the word penis is penile. This adjective is commonly used in describing various accessory structures of male copulatory organs found in many kinds of invertebrate animals.

Human use of animal penises

Main article: Pizzle

Pizzles are represented in heraldry, where the adjective pizzled (or vilené) indicates that part of an animate charge's anatomy, especially if coloured differently.

See also

• Buried penis
• Castration anxiety
• Diphallia
• Dildo
• Erogenous zone
• Koteka

• Micropenis
• Penis enlargement
• Penis envy
• Penis removal
• Phallic architecture

• Preputioplasty
• Pubic hair
• Stamen
• Stunt cock
• Testicle

References

Notes

Bibliography

Horses

• Walker, Donald F.; Vaughan, John T. (1 June 1980). Bovine and equine urogenital surgery. Lea & Febiger. ISBN 978-0-8121-0284-0. Retrieved 23 July 2013. 
• "The Stallion: Breeding Soundness Examination & Reproductive Anatomy". University of Wisconsin-Madison. Archived from the original on 2007-07-16. Retrieved 7 July 2007. 
• Munroe, Graham; Weese, Scott (15 March 2011). Equine Clinical Medicine, Surgery and Reproduction. Manson Publishing. ISBN 978-1-84076-608-0. Retrieved 18 February 2014. 
• Budras, Klaus Dieter; Sack (1 March 2012). Anatomy of the Horse. Manson Publishing. ISBN 978-3-8426-8368-6. Retrieved 1 July 2013. 
• England, Gary (15 April 2008). Fertility and Obstetrics in the Horse. John Wiley & Sons. ISBN 978-0-470-75041-4. Retrieved 18 February 2014. 
• Equine Research (2004). Horse Conformation: Structure, Soundness, and Performance. Lyons Press. ISBN 978-1-59228-487-0. Retrieved 23 July 2013. 
• Evans, James Warren (15 February 1990). The Horse. W. H. Freeman. ISBN 978-0-7167-1811-6. Retrieved 23 July 2013. 
• Hayes, M. Horace; Rossdale, Peter D. (March 1988). Veterinary Notes for Horse Owners: An Illustrated Manual of Horse Medicine and Surgery. Simon & Schuster. ISBN 978-0-671-76561-3. Retrieved 1 July 2013. 
• McBane, Susan (2001). Modern Horse Breeding: A Guide for Owners. Globe Pequot Press. ISBN 978-1-58574-389-6. Retrieved 18 February 2014. 

Marsupials

• Parker, Rick (13 January 2012). Equine Science (4 ed.). Cengage Learning. ISBN 1-111-13877-X. Retrieved 18 February 2014. 
• Flannery, Tim (2008). Chasing Kangaroos: A Continent, a Scientist, and a Search for the World's Most Extraordinary Creature. Grove/Atlantic, Incorporated. pp. 60–. ISBN 9780802143716. Retrieved 5 May 2013. 
• Hunsaker, Don II (2 December 2012). The Biology of Marsupials. Elsevier Science. ISBN 978-0-323-14620-3. Retrieved 18 February 2014. 
• Jones, Menna E.; Dickman, Chris R.; Archer, Mike; Archer, Michael (2003). Predators With Pouches: The Biology of Carnivorous Marsupials. Csiro Publishing. ISBN 9780643066342. Retrieved 5 May 2013. 
• King, Anna (2001). "Discoveries about Marsupial Reproduction". Iowa State University Biology Dept. Retrieved 2012-11-22. 
• Stonehouse, Bernard; Gilmore, Desmond (1977). The Biology of marsupials. University Park Press. ISBN 978-0-8391-0852-8. Retrieved 25 July 2013. 
• Tyndale-Biscoe, C. Hugh (2005). Life of Marsupials. Csiro Publishing. ISBN 978-0-643-06257-3. Retrieved 18 February 2014. 

Other animals

• Austin, Colin Russell; Short, Roger Valentine (21 March 1985). Reproduction in Mammals: Volume 4, Reproductive Fitness. Cambridge University Press. ISBN 978-0-521-31984-3. Retrieved 22 July 2013. 
• Bassert, Joanna M.; McCurnin, Dennis M. (1 April 2013). McCurnin's Clinical Textbook for Veterinary Technicians. Elsevier Health Sciences. ISBN 1-4557-2884-5. Retrieved 18 February 2014. 
• Beck, Benjamin B.; Wemmer, Christen M. (1983). The Biology and management of an extinct species: Père David's deer. Noyes Publications. ISBN 978-0-8155-0938-7. Retrieved 5 July 2013. 
• Burns, Eugene (1953). The sex life of wild animals: a North American study. Rinehart. Retrieved 23 July 2013. 
• Carnaby, Trevor (22 January 2007). Beat About the Bush: Mammals. Jacana Media. ISBN 978-1-77009-240-2. Retrieved 19 July 2013. 
• Edmund, Alfred (1895). Brehm's Life of Animals. Chicago: A. N. Marquis & Company. Retrieved 2013-11-08. 
• Elbroch, Lawrence Mark; Kresky, Michael Raymond; Evans, Jonah Wy (7 April 2012). Field Guide to Animal Tracks and Scat of California. University of California Press. ISBN 978-0-520-95164-8. Retrieved 5 July 2013. 
• Eltringham, Stewart Keith (1979). The ecology and conservation of large African mammals. Macmillan. ISBN 978-0-333-23580-5. Retrieved 20 July 2013. 
• Frandson, Rowen D.; Wilke, W. Lee; Fails, Anna Dee (30 June 2009). Anatomy and Physiology of Farm Animals. John Wiley & Sons. ISBN 978-0-8138-1394-3. Retrieved 1 July 2013. 
• Geist, Valerius (1993). Elk Country. T&N Children's Publishing. ISBN 978-1-55971-208-8. Retrieved 5 July 2013. 
• Hayssen, Virginia Douglass (1993). Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-Specific Data. Cornell University Press. ISBN 978-0-8014-1753-5. Retrieved 23 July 2013. 
• Heptner, V. G.; Sludskii, A. A. (2002). Mammals of the Soviet Union. Vol. II, part 1b, Carnivores (Mustelidae and Procyonidae). Washington, D.C. : Smithsonian Institution Libraries and National Science Foundation. ISBN 90-04-08876-8. Retrieved 2013-11-08. 
• Hoffmeister, Donald F. (2002). Mammals of Illinois. University of Illinois Press. ISBN 978-0-252-07083-9. Retrieved 22 July 2013. 
• Horowitz, Barbara N.; Bowers, Kathryn (12 June 2012). Zoobiquity: What Animals Can Teach Us About Being Human. Doubleday Canada. ISBN 978-0-385-67061-6. Retrieved 25 July 2013. 
• Horwich, =Robert H. (June 1972). The ontogeny of social behavior in the gray squirrel (Sciurus carolinensis). P. Parey. ISBN 978-3-489-68036-9. Retrieved 23 July 2013. 
• Jackson, Hartley H. (January 1961). Mammals of Wisconsin. Univ of Wisconsin Press. ISBN 978-0-299-02150-4. Retrieved 22 July 2013. 
• Journal of the Mammalogical Society of Japan. The Society. 1986. Retrieved 5 July 2013. 
• Khanna, Dev Raj; Yadav, P. R. (1 January 2005). Biology Of Mammals. Discovery Publishing House. ISBN 978-81-7141-934-0. Retrieved 20 July 2013. 
• Kingdon, Jonathan (January 1984). East African Mammals: An Atlas of Evolution in Africa. Vol. I. University of Chicago Press. ISBN 978-0-226-43718-7. Retrieved 22 July 2013. 
• Kingdon, Jonathan; Michael Hoffmann, Meredith Happold, Jan Kalina (23 May 2013). Mammals of Africa. A&C Black. ISBN 978-1-4081-8996-2. Retrieved 20 July 2013. 
• König, Horst Erich; Liebich, Hans-Georg (2007). Veterinary Anatomy of Domestic Mammals: Textbook and Colour Atlas. Schattauer Verlag. ISBN 978-3-7945-2485-3. Retrieved 23 July 2013. 
• Kotpal, R. L. (2010). Modern Text Book Of Zoology Vertebrates. Rastogi Publications. ISBN 978-81-7133-891-7. Retrieved 23 July 2013. 
• Krause, William J. (1 March 2008). An Atlas of Opossum Organogenesis. Universal-Publishers. ISBN 978-1-58112-969-4. Retrieved 20 July 2013. 
• Linzey, Donald W. (28 December 2011). Vertebrate Biology. JHU Press. ISBN 978-1-4214-0040-2. Retrieved 20 July 2013. 
• Lukefahr, Steven D.; Cheeke, Peter R.; Patton, Nephi M. (2013). Rabbit Production. CABI. ISBN 978-1-78064-012-9. Retrieved 20 July 2013. 
• Natural History Bulletin of the Siam Society. 1975. Retrieved 5 July 2013. 
• Rose, Kenneth D.; Archibald, J. David (22 February 2005). The Rise of Placental Mammals: Origins and Relationships of the Major Extant Clades. JHU Press. ISBN 978-0-8018-8022-3. Retrieved 22 July 2013. 
• Roze, Uldis (2009). The North American Porcupine. Cornell University Press. ISBN 978-0-8014-4646-7. Retrieved 25 July 2013. 
• Sarkar, Amita (1 January 2003). Sexual Behaviour In Animals. Discovery Publishing House. ISBN 978-81-7141-746-9. Retrieved 20 July 2013. 
• Schatten, Heide; Constantinescu, Gheorghe M. (21 March 2008). Comparative Reproductive Biology. John Wiley & Sons. ISBN 978-0-470-39025-2. Retrieved 23 July 2013. 
• Small, Meredith F. (1993). Female Choices: Sexual Behavior of Female Primates. Cornell University Press. ISBN 978-0-8014-8305-9. Retrieved 23 July 2013. 
• Skinner, J. D.; Chimimba, Christian T. (15 November 2005). The Mammals of the Southern African Sub-region. Cambridge University Press. ISBN 978-0-521-84418-5. Retrieved 19 July 2013. 
• Staker, Lynda (2006). The Complete Guide to the Care of Macropods: A Comprehensive Guide to the Handrearing, Rehabilitation and Captive Management of Kangaroo Species. ISBN 978-0-9775751-0-7. Retrieved 19 July 2013. 
• Strum, Shirley C.; Fedigan, Linda Marie (15 August 2000). Primate Encounters: Models of Science, Gender, and Society. University of Chicago Press. ISBN 978-0-226-77754-2. Retrieved 22 July 2013. 
• Sturtz, Robin; Asprea, Lori (30 July 2012). Anatomy and Physiology for Veterinary Technicians and Nurses: A Clinical Approach. John Wiley & Sons. ISBN 978-1-118-40585-7. Retrieved 22 July 2013. 
• Towsley, Bryce (13 August 2008). Big Bucks The Benoit Way: Secrets From America's First Family of Whitetail Hunting. Krause Publications. p. 57. ISBN 978-1-4402-2631-1. Retrieved 5 July 2013. 
• Verts, B. J.; Carraway, Leslie N. (1998). Land Mammals of Oregon. University of California Press. p. 41. ISBN 978-0-520-21199-5. Retrieved 20 July 2013. 
• Wilson, Don E.; Reeder, DeeAnn M. (16 November 2005). Mammal Species of the World: A Taxonomic and Geographic Reference. JHU Press. ISBN 0801882214. Retrieved 20 July 2013. 

External links

• Media related to Penis at Wikimedia Commons
• Kinsey Institute on the penis

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 包皮非切除者の陰茎のケア care of the uncircumcised penis
• 2. 陰茎癌：臨床症状および診断 carcinoma of the penis clinical presentation and diagnosis
• 3. ペイロニー病：診断と内科的マネージメント peyronies disease diagnosis and medical management
• 4. 小児における亀頭包皮炎：臨床症状、診断、および治療 balanoposthitis in children clinical manifestations diagnosis and treatment
• 5. 小児における身体的診察：会陰 the pediatric physical examination the perineum

English Journal

• Novel PTEN germline mutation in a family with mild phenotype: Difficulties in genetic counseling.

• Busa T, Chabrol B, Perret O, Longy M, Philip N.SourceUnité de génétique clinique, APHM, CHU Timone-Enfants, France. Electronic address: tiffany.busa@ap-hm.fr.
• Gene.Gene.2013 Jan 10;512(2):194-7. doi: 10.1016/j.gene.2012.09.134. Epub 2012 Nov 2.
• PTEN gene (phosphatase and tensin homolog deleted on chromosome ten, MIM 601628) is a tumor suppressor gene implicated in PTEN hamartoma tumor syndromes (PHTS) including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome and Proteus-like syndrome. PTEN mutations have been more recently reported in c
• PMID 23124040

• Partial Penile Amputation due to Penile Tourniquet Syndrome in a Child Troubled With Primary Nocturnal Enuresis - A Rare Emergency.

• Pahwa HS, Kumar A, Srivastava R, Kumar S, Goel A, Ahmad A.SourceDepartment of Surgery, K.G.'s Medical University, Lucknow, Uttar Pradesh, India. Electronic address: pahwakgmu@yahoo.co.in.
• Urology.Urology.2013 Jan 3. pii: S0090-4295(12)01389-1. doi: 10.1016/j.urology.2012.11.012. [Epub ahead of print]
• Penile tourniquet syndrome (PTS) or acquired constriction ring syndrome (ACRS) is a rare emergency that can lead to a wide range of vascular and soft tissue injuries in the penis. We are presenting a case of penile tourniquet syndrome in an 8-year-old child who had tied a thread around his penis due
• PMID 23290150

Japanese Journal

• 感染を合併した陰茎縫線囊腫の1例

• 渡邉 雄一
• 西日本泌尿器科 = The Nishinihon journal of urology 74(12), 710-713, 2012-12-00
• NAID 40019524223

• 陰茎化学熱傷の1例

• 米田 傑,金城 孝則,種田 建史 他
• 泌尿器科紀要 = Acta urologica Japonica 58(11), 625-627, 2012-11-00
• … In addition, a chemical burn of the penis is quite rare. … We experienced a case of chemical burn of the penis caused by resin for making fiber-glass reinforced plastics (FRP). … He had sustained an injury to his penis induced by FRP at his workplace and had developed phimosis by the severe edematous foreskin. …
• NAID 40019497532

• 自傷による陰茎切断の3例

• 米田 傑,金城 孝則,種田 建史 他
• 泌尿器科紀要 = Acta urologica Japonica 58(11), 621-623, 2012-11-00
• … He amputated his penis using a utility knife. … He amputated his penis using a kitchen knife. … He amputated his penis using a piece of broken glass. …
• NAID 40019497432

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22 Aug 2012 ... Updated (05-09-2012) 4 countries added Updated a mistake with UK(12-15- 2011) Scotland:14.73 cm, 5.8 inches, Bioinformatics Research Centre, 2008 Updated to 2011/03/16 Source of centers ...

Related Pictures

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★リンクテーブル★

リンク元	「陰茎」「penile」「ペニス」「penes」

「陰茎」

　　[★]

英

penis (Z)

関

外生殖器、生殖器、泌尿器

• 女性の外生殖器では陰核小陰唇に相当

「penile」

　　[★]

• adj.

• ペニスの、陰茎の、男根の

関

(n.)penis

　

「ペニス」

　　[★]

英

penis、penile

関

陰茎、陰茎亀頭

「penes」

　　[★]

陰茎

関

penile、penis