Ilioinguinal nerve

Nerve: Ilioinguinal nerve
Plan of the lumbar plexus. The ilioinguinal is visible at the upper left.
The lumbar plexus and its branches. The ilioinguinal nerve is visible at the upper left.
Latin	nervus ilioinguinalis
Gray's	subject #212 952
Innervates	Skin over the root of the penis and upper part of the scrotum (male), skin covering the mons pubis and labium majus (female)
From	lumbar plexus

The ilioinguinal nerve is a branch of the first lumbar nerve (L1). It separates from the first lumbar nerve along with the larger iliohypogastric nerve.

It emerges from the lateral border of the psoas major just inferior to the iliohypogastric, and passes obliquely across the quadratus lumborum and iliacus. The ilioinguinal nerve then perforates the transversus abdominis near the anterior part of the iliac crest, and communicates with the iliohypogastric nerve between the transversus and the obliquus internus.

It then pierces the obliquus internus, distributing filaments to it, and then accompanies the spermatic cord through the superficial inguinal ring. Its fibers are then distributed to the skin of the upper and medial part of the thigh, and to the following locations in the male and female:

• In the male ("anterior scrotal nerve"): to the skin over the root of the penis and upper part of the scrotum.
• In the female ("anterior labial nerve"): to the skin covering the mons pubis and labium majus.

Note that the ilioinguinal nerve does not pass through the deep inguinal ring, and therefore it only travels through part of the inguinal canal.

Variations

The size of this nerve is in inverse proportion to that of the iliohypogastric.

Occasionally it is very small, and ends by joining the iliohypogastric; in such cases, a branch from the iliohypogastric takes the place of the ilioinguinal, or the latter nerve may be altogether absent.

Additional images

• 

  Deep and superficial dissection of the lumbar plexus.

• 

  Cutaneous nerves of the right lower extremity. Front and posterior views.

• 

  Cutaneous nerves of the right lower extremity. Front and posterior views.

External links

• Duke Orthopedics ilioinguinal_nerve
• Atlas of anatomy at UMich abdo_wall70 - "Posterior abdominal wall, dissection, anterior view"
• SUNY Labs 35:05-0102 - "Anterior Abdominal Wall: The Iliohypogastric and IlioInguinal Nerves"
• SUNY Labs 40:17-0102 - "Posterior Abdominal Wall: Nerves of the Lumbar Plexus"
• SUNY Anatomy Image 7433
• Anatomy at MUN nerve/lumbnerv
• posteriorabdomen at The Anatomy Lesson by Wesley Norman (Georgetown University) (posteriorabdmus&nerves)

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.