Ilioinguinal nerve
Encyclopedia
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:
Note that the ilioinguinal nerve does not pass through the deep inguinal ring
, and therefore it only travels through part of the inguinal canal
.
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.
Iliohypogastric nerve
The iliohypogastric nerve is the superior branch of the anterior ramus of spinal nerve L1 after this nerve receives fibers from T12 . The inferior branch is the ilioinguinal 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
Iliac crest
-External links: - "Superficial muscles of the gluteal region and posterior thigh." - "Anterior Abdominal Wall: Osteology and Surface Anatomy " - "The Back, Posterior View" * *...
, and communicates with the iliohypogastric nerve between the transversus and the obliquus internus
Abdominal internal oblique muscle
The internal oblique muscle is the intermediate muscle of the abdomen, lying just underneath the external oblique and just above the transverse abdominal muscle.-Structure:...
.
It then pierces the obliquus internus, distributing filaments to it, and then accompanies the spermatic cord
Spermatic cord
The spermatic cord is the name given to the cord-like structure in males formed by the ductus deferens and surrounding tissue that run from the abdomen down to each testicle.-Contents of spermatic cord:...
through the superficial inguinal ring
Superficial inguinal ring
The superficial inguinal ring is an anatomical structure in the anterior wall of the human abdomen. It is a triangular opening that forms the exit of the inguinal canal, which houses the ilioinguinal nerve, the genital branch of the genitofemoral nerve, and the spermatic cord or the round ligament...
. Its fibers are then distributed to the skin of the upper and medial part of the thigh
Thigh
In humans the thigh is the area between the pelvis and the knee. Anatomically, it is part of the lower limb.The single bone in the thigh is called the femur...
, and to the following locations in the male and female:
- In the male ("anterior scrotal nerve"): to the skin over the root of the penisPenisThe penis is a biological feature of male animals including both vertebrates and invertebrates...
and upper part of the scrotumScrotumIn 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...
. - In the female ("anterior labial nerve"): to the skin covering the mons pubisMons pubisIn human anatomy or in mammals in general, the mons pubis , also known as the mons veneris or simply the mons, is the adipose tissue lying above the pubic bone of adult females, anterior to the pubic symphysis...
and labium majus.
Note that the ilioinguinal nerve does not pass through the deep inguinal ring
Deep inguinal ring
The deep inguinal ring is the entrance to the inguinal canal.-Location:...
, and therefore it only travels through part of the inguinal canal
Inguinal canal
The inguinal canal is a passage in the anterior abdominal wall which in men conveys the spermatic cord and in women the round ligament. The inguinal canal is larger and more prominent in men.-Site:...
.
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.