出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/01/03 22:03:36」(JST)
| It has been suggested that Deep inguinal ring be merged into this article. (Discuss) Proposed since October 2014. |
| Inguinal canal | |
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Front of abdomen, showing surface markings for arteries and inguinal canal. (Inguinal canal is tube at lower left.)
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The scrotum. On the left side the cavity of the tunica vaginalis has been opened; on the right side only the layers superficial to the Cremaster have been removed. (Right inguinal canal visible at upper left.)
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| Details | |
| Latin | canalis inguinalis |
| Identifiers | |
| Gray's | p.1239 |
| MeSH | A01.047.412 |
| TA | A04.5.01.026 |
| FMA | 19928 |
| Anatomical terminology | |
The inguinal canal is a passage in the anterior abdominal wall that in men conveys the spermatic cord and in women the round ligament of uterus. The inguinal canal is larger and more prominent in men. There is one inguinal canal on each side of the midline.
The inguinal canal is situated just above the medial half of the inguinal ligament. In both sexes the canal transmits the ilioinguinal nerve. The canal is approximately 3.75 to 4 cm long.[citation needed], angled anteroinferiorly and medially.
A first-order approximation is to visualize the canal as a cylinder.[1]
To help define the boundaries, the canal is often further approximated as a box with six sides. Not including the two rings, the remaining four sides are usually called the "anterior wall", "posterior wall", "roof", and "floor".[2] These consist of the following:
| superior wall (roof): Medial crus of aponeurosis of external oblique |
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| anterior wall: aponeurosis of external oblique |
(inguinal canal) | posterior wall: transversalis fascia |
| inferior wall (floor): inguinal ligament |
During development gonads (ovaries or testes) descend from their starting point on the posterior abdominal wall (para-aortically) from labioscrotal swelling near the kidneys down the abdomen and through the inguinal canal to reach the scrotum. The testis then descends through the abdominal wall into the scrotum, behind the processus vaginalis (which later obliterates). Thus lymphatic spread from a testicular tumour is to the para-aortic nodes first, and not the inguinal nodes.
The structures which pass through the canal differ between males and females:
The classic description of the contents of spermatic cord in the male are:
3 arteries: artery to vas deferens (or ductus deferens), testicular artery, cremasteric artery;
3 fascial layers: external spermatic, cremasteric, and internal spermatic fascia;
3 other structures: pampiniform plexus, vas deferens (ductus deferens), testicular lymphatics;
3 nerves: genital branch of the genitofemoral nerve (L1/2), sympathetic and visceral afferent fibres, ilioinguinal nerve (N.B. outside spermatic cord but travels next to it)
Note that the ilioinguinal nerve passes through the superficial ring to descend into the scrotum, but does not formally run through the canal.
Abdominal contents (potentially including intestine) can be abnormally displaced from the abdominal cavity. Where these contents exit through the inguinal canal the condition is known as an indirect or oblique inguinal hernia. This can also cause infertility. This condition is far more common in men than in women, owing to the inguinal canal's small size in women.
A hernia that exits the abdominal cavity directly through the deep layers of the abdominal wall, thereby bypassing the inguinal canal, is known as a direct inguinal hernia.
| Wikimedia Commons has media related to Inguinal canal. |
The spermatic cord in the inguinal canal.
Inguinal fossae
^ Adam Mitchell; Drake, Richard; Gray, Henry David; Wayne Vogl (2010). Gray's anatomy for students. Elsevier/Churchill Livingstone. pp. 286. ISBN 0-443-06612-4.
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| リンク元 | 「鼡径管」 |
| 関連記事 | 「canal」「inguinal」 |