nervous system: the sensory and control apparatus consisting of a network of nerve cells
system: a group of physiologically or anatomically related organs or parts
theravada: one of two great schools of Buddhist doctrine emphasizing personal salvation through your own efforts; a conservative form of Buddhism that adheres to Pali scriptures and the non-theistic ideal of self purification to nirvana; the dominant religion of Sri Lanka (Ceylon) and Myanmar (Burma) and Thailand and Laos and Cambodia