Q. What is nervous system? Ans.: The brain, spinal cord and nerves form the nervous system. The spinal cord starts from the skull & extends down in the vertebral column ending just below the thoracic spine. The spine. The spinal cord is enclosed in the vertebral column which is a protective frame work for it. From either sides of from the gap in between 2 vertebras nerve roots come out. Multiple nerve roots from various vertebra bodies join together to form a network called nervous plexus from these plexus emerge out nerves which comes towards the limbs. In the lower limb – 2 nerves come down the femoral and sciatic. In the upper limb -3 nerves come down-median, ulnar, radial. When there is pain coming down along this sciatic nerve. It is called sciatica. The pain along this nerves run from back of the thigh into the calf into the foot, this is called Sciatica. Ashwini Multispeciality Hospital treat for the best spine surgery by best orthopeadic & best neurosurgeon in nashik.