system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
True statement about the upper half of anal canal is -
assistant
The correct answer is  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).