The genitofemoral nerve refers to a

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the ...

that is found in the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the tors ...

. Its branches, the genital branch and femoral branch supply sensation to the upper anterior thigh, as well as the skin of the anterior scrotum in males and mons pubis in females. The femoral branch is different from the femoral nerve, which also arises from the lumbar plexus.

Anatomy

The genitofemoral nerve originates from the upper L1-2 segments of the lumbar plexus. It passes downwards, pierces the psoas major and emerges from its anterior surface. The nerve divides into two branches, the genital branch and the

lumboinguinal nerve The lumboinguinal nerve, also known as the femoral or crural branch of genitofemoral, is a nerve in the abdomen. The lumboinguinal nerve is a branch of the genitofemoral nerve. The "femoral" part supplies skin to the femoral triangle area. Struc ...

also known as the femoral branch, both of which then continue downwards and medially to the inguinal and femoral canal respectively.

Genital Branch

The genital branch continues downward on the surface of the psoas major muscle and then enters the inguinal canal through the deep inguinal ring. In men, the genital branch supplies the cremaster and scrotal skin. In women, the genital branch accompanies the round ligament of uterus, terminating in and innervating the skin of the mons pubis and labia majora.

Femoral Branch

The femoral branch passes underneath the inguinal ligament, travelling through the lateral muscular compartment of the femoral sheath where it innervates skin of the upper leg. Passing through the cribriform fascia of the saphenous opening of the fascia lata of the thigh, it then supplies the skin of the upper, anterior and medial side of thigh.

Variation

The genitofemoral nerve typically pierces and passes through the psoas major muscle before bifurcating into a genital branch and a femoral branch midway along its anterior surface. In approximately 25% of cases, the genitofemoral nerve splits into these branches ''before'' it enters the psoas major or ''within'' the muscle belly of psoas major (with fibers of the psoas major separating the genital and femoral branches). Usually this variation causes the split to be occur earlier in the genitofemoral nerve, at the upper rather than mid-portion of the anterior surface of the psoas major.

Embryology

The genitofemoral nerve is formed in the midsection of the psoas muscle by the union of branches from the anterior rami of L1 and L2 nerve roots

Function

The genitofemoral nerve is responsible for both the sensory (femoral branch) and motor portions (genital branch) of the cremasteric reflex, which describes contraction of the cremasteric muscle when the skin of the superior medial part of the thigh is touched.

Additional images

File:Gray824.png, Deep and superficial dissection of the lumbar plexus. File:Slide6w.JPG, Genitofemoral nerve

References

External links

* - "Inguinal Region, Scrotum and Testes: Layers of the spermatic cord" * - "Muscles and nerves of the posterior abdominal wall." * () {{Authority control Nerves of the lower limb and lower torso