nervous system 
noun
The network of nerve cells and fibres which transmits nerve impulses between parts of the body. See also autonomic nervous system, central nervous system, peripheral nervous system.Composed of neurones and nerve fibres, the nervous system is part of the physical body....
- Milk thistle was the only herb that boosted both the immune and nervous systems, helping nerve cells produce more neurites and keeping cells alive longer.
- The enteric nervous system has a central role in the control of most gastrointestinal functions.