What is the spinal level for the ilioinguinal nerve?

What is the spinal level for the ilioinguinal nerve?

• A. L1, L2
• B. T12
• C. L4
• D. L1

Answer: (D)

The ilioinguinal nerve comes from the ventral ramus of the first lumbar nerve. In the lumbar plexus, it is commonly described together with the iliohypogastric nerve as carrying L1 fibers. Its primary course and distribution are tied to L1, supplying sensory areas like the upper medial thigh and the external genitalia. Some sources note a tiny contribution from nearby levels in some individuals, but the best and most consistent level to identify for this nerve is L1. T12 corresponds to the subcostal nerve, and L4 relates to other nerves such as the obturator/femoral nerves, not the ilioinguinal.

The ilioinguinal nerve comes from the ventral ramus of the first lumbar nerve. In the lumbar plexus, it is commonly described together with the iliohypogastric nerve as carrying L1 fibers. Its primary course and distribution are tied to L1, supplying sensory areas like the upper medial thigh and the external genitalia. Some sources note a tiny contribution from nearby levels in some individuals, but the best and most consistent level to identify for this nerve is L1. T12 corresponds to the subcostal nerve, and L4 relates to other nerves such as the obturator/femoral nerves, not the ilioinguinal.