Genitofemoral nerve


The genitofemoral nerve refers to a nerve that is found in the abdomen. 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 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 passes through the deep inguinal ring and enters the inguinal canal. 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 canal 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. 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

Function

The genitofemoral nerve is responsible for both the sensory and motor portions 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