A pt. operated for direct inguinal hernia developed anethesia at the root of the penis and adjacent part of the scrotum the nerve likely to be injured is :
Ans. is 'd' ie ilioinguinal nerve All the three nerves ie genitofemoral, ilioinguinal & iliohypogastric are branches of the lumbar plexus and all may be injured in op. for hernia.Ilioinguinal-Nerveenters the inguinal canal by piercing the internal oblique muscle (not through the deep ring)*it then emerges from the superficial inguinal ring to supply skin ofproximal medial skin of the thighskin over the penile root.upper part of the scrotumIliohypogastric nervesdivides into two branches - lateral cutaneous and anterior cutaneous.lateral cutaneous supplies - posterolateral gluteal skinAnterior cutaneous supplies - suprapubic skinGenitofemoral nervedivides into two branchesGenital andFemoralGenital br of Genitofemoral nerve - enters the inguinal canal at its deep ring and suppliesthe Cremaster*the scrotal skin*Femoral br of genitofemoral nervepasses behind the inguinal ligament, enters the femoral sheath lateral to femoral artery*, pierces the antlayer of the femoral sheath and fascia lata and supplies the skin anterior to the upper part of femoral triangle.From these descriptions it is obvious that the nerve likely to be injured is ilioinguinal nerve.
Genital br. of genitofemoral nerve (supply dartos muscle)
Femoral br. of genitofemoral nerve
Iliohypogastric nerve
Ilioinguinal nerve
Thyroid Gland