During a radical prostatectomy, injury to the neurovascular bundles running posterolateral to the prostate at the 5 and 7 o'clock positions causes erectile dysfunction. These bundles contain fibres from which autonomic source?

• A Superior hypogastric plexus (sympathetic L1–L2)
• B Pudendal nerve (somatic S3–S4)
• C Cavernous nerves derived from the inferior hypogastric plexus (parasympathetic S2–S4) ✓
• D Genitofemoral nerve (L1–L2)

Explanation

Cavernous nerves (nervi cavernosi) arise from the inferior hypogastric (pelvic) plexus and carry parasympathetic fibres from S2–S4 along with sympathetic fibres. They run in the neurovascular bundles of Walsh, posterolateral to the prostate. Parasympathetic stimulation releases nitric oxide via non-adrenergic non-cholinergic (NANC) neurotransmission, causing penile erection through cavernosal smooth muscle relaxation. Injury leads to erectile dysfunction — a major complication of radical prostatectomy.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

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