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What is True statement about the upper half of anal canal is - and explain in detail?
Upper part of anal canal above pectinate line is supplied by autonomic nerves and is therefore insensitive to pain.
Upper part of anal canal above pectinate line is drained by inferior mesenteric node (into internal iliac nodes), lined by columnar epithelium and is supplied by superior rectal artery (Continuation of inferior mesenteric artery).