Aurologist is teaching her resident to perform a vasectomy. She explains that he has to inject the anesthetic in the skin of the scrotum, in preparation for incision of its lateral aspect. This surgical location allows for easy access to the spermatic cord. Which of the following nerves innervates the skin of the scrotum?
- femoral nerve
- iliohypogastric nerve
- ilioinguinal nerve
- obturator nerve
- subcostal nerve
Answer(s): C
Explanation:
The anterior aspect of the scrotum is innervated by branches of the ilioinguinal nerve (L1).Other nerves innervating the scrotum are branches of the genitofemoral nerve (L1, L2), pudendal nerve (S2-S4), and posterior femoral cutaneous nerve (S2, S3). The femoral nerve (L2-L4, choice A) supplies sensory innervations to the anteromedial thigh, hip joint, and knee joint. It also innervates muscles of the anterior compartment of the thigh. The iliohypograstric nerve (L1, choice B) provides sensory innervations over the iliac crest and the hypogastric region. The obturator nerve (L2-L4, choice D) supplies motor innervation to the medial compartment of the thigh. The subcostal nerve (T12, choice E) provides motor innervation for the lower part of the external oblique muscle and sensory innervations over the hip and anterior superior iliac spine.