The gut possesses an intrinsic nervous system, termed the 'second brain,' capable of functioning and controlling reflexes independently of the central nervous system.

“indicating that the intestinal nervous system is able to function independently of the cns of the central nervous system”

“the gut has its own intrinsic nervous system and i've called that the second brain and that's the title of the book by the way and the reason i called it the second brain is that like the brain in the head the nervous system of the gut is able to function and control reflexes and behavior independently of any influence from the brain or spinal cord”