● The bile duct and the pancreatic duct open together into the duodenum as the common hepato-pancreatic duct which is guarded by a sphincter called the sphincter of Oddi. ● Ileo-caecal valve is present at the junction of ileum and caecum to prevent the backflow of faecal matter into the ileum in humans. ● Gastro-oesphageal sphincter regulates the opening of oesophagus into stomach.