Ans: In simple definition, Peripheral Nervous System is described as the nervous system present outside the brain and the spinal cord. It is simply denoted as PNS. In bilateral animals, the peripheral nervous system plays a vital role to make up the nervous system by its two components (Chandran, 2016). There is also an important nervous system present in animals, which is called Central Nervous system or CNS with which PNS acts in animal nervous system to maintain the activity of both the nervous systems.