Question

how can you justify entric nervous system as second brain

Answer 1

the enteric nervous system is often refers to as secnd brain because there are hundreds of millions of neurons connected to brain to the enteric nervous system.thw part of the nervous system that is tasked with controlling gastrointestinal nervous system.

Answer 2

Since it enteric nervous system has the capacity to alter its response depending on such factors as bulk and nutrient composition. In addition, ENS contains support cells which are similar to astroglia or astrocyte( star shaped cells) of the brain and a diffusion barrier around the capillaries surrounding ganglia( structure containaing a lot of nerve cells to form neurofibre) which is similar to the blood–brain barrier of cerebral blood vessels. It also uses more than 30 neurotransmitters most of which are found in CNS like actylcholine , dopamine and serotonin and other functions . Also it has structural and chemical parallels to the brain. Due to this it can be called a 'kind' of brain but not exactly a brain.

Hope this helps you.