Nerve supply above pectinate line is through ?: (A) Inferior rectal nerve, (B) Pudendal nerve, (C) Autonomic nerves, (D) Perineal branch of S4
Answer is C. Nerve supply of anal canalMucous membrane above pectinate line is supplied by autonomic nerves (sympathetic L1 L2 and parasympathetic: S2 S3 S4) and therefore is insensitive to pain.Pa below the pectinate line is supplied by somatic nerves (inferior rectal nerve a branch of pudendal nerve) and therefore is sensitive to pain.Thus pain sensations are carried by pudendal nerve.