The genitofemoral nerve is a branch of the lumbar plexus that carries fibers from the anterior rami of spinal nerves L1 and L2. The nerve originates in the substance of the psoas major muscle and descends retroperitoneally towards the inguinal ligament.
The genitofemoral nerve ends by giving off two terminal branches: the femoral (lumboinguinal) branch and the genital branch. This bifurcation usually takes place after the nerve pierces the psoas fascia, or after it crosses the ureter.
The genitofemoral nerve is primarily a sensory nerve that provides supply to the upper thigh region in both sexes. Specifically, it supplies the mons pubis and labia majora in females, and the skin of the anterior scrotum in males. In addition, the genitofemoral nerve carries motor fibers to innervate the cremaster muscle in males.
This article will discuss the anatomy and function of the genitofemoral nerve.
|Origin||Lumbar plexus (L1, L2)|
|Branches||Genital branch, femoral (lumboinguinal) branch|
Both sexes: Upper thigh region
Males: Anterior scrotal skin
Females: Mons pubis, labia majora
|Motor supply||Males: Cremaster muscle|
- Origin and course
- Branches and innervation
- Clinical relations
Origin and course
The genitofemoral nerve originates within the substance of the psoas major muscle by the union of the anterior rami of spinal nerves L1 and L2. After passing through the psoas major muscle, the nerve emerges on its anterior surface and continues to descend retroperitoneally towards the inguinal ligament.
Before it reaches the inguinal ligament, the genitofemoral nerve crosses the ureter posteriorly and bifurcates into two terminal branches: genital and femoral branches. It's important to note that the location of this bifurcation is very variable and it can occur anywhere along its course, even right after its origin.
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Branches and innervation
The genitofemoral nerve ends in a bifurcation, providing two terminal branches:
- Genital branch
- Femoral branch
Genital branch of genitofemoral nerve
Upon its origin, the genital branch courses inferiorly, crosses the external iliac artery and enters the inguinal canal via the deep inguinal ring. In the inguinal canal, the genital branch is accompanied by the spermatic cord (in males) or the round ligament (in females). It exits the inguinal canal through the superficial inguinal ring and provides supply to the external genitalia.
More specifically, the genital branch provides sensory supply for the anterior portion of the scrotal skin in males, and supplies the mons pubis and labia majora in females. Its motor fibers innervate the cremaster muscle in males.
It is worth mentioning that the genitofemoral nerve is mainly responsible for the cremasteric reflex, as it supplies sensation to the superior medial aspect of the thigh and motor innervation to the cremaster muscle. The cremasteric reflex is a valuable part of physical examination, especially in the evaluation of acute scrotal pain and the assessment for testicular torsion.
Femoral branch of genitofemoral nerve
The femoral branch (also known as the lumboinguinal branch) courses lateral to the external iliac artery towards the inguinal ligament. It then travels underneath the inguinal ligament, pierces the femoral sheath and fascia lata, and enters the thigh region.
In contrast to the genital branch, the femoral branch is solely a sensory branch. It supplies the skin of the anterior, upper, and medial aspects of the thigh.
Do you want to know more about the lumbar plexus? Check out our study unit and article to learn everything that you need to know about the lumbar plexus.
Genitofemoral neuralgia is a syndrome characterized by severe pain in the lower abdomen due to the compression of the genitofemoral nerve. The pain can be distributed anywhere along the path of the nerve and its branches. It is usually sharp and unilateral and can occur in both males and females. In most cases, the compression of the nerve takes place during its course through the inguinal canal, usually after open hernia surgery.
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