Spinal anaesthetic. Computer artwork of the injection of a spinal anaesthetic into a woman's lower back. The anaesthetic drug is being injected near the spinal cord, between the L3 and L4 vertebrae of the lower back (lumbar) region. The spinal cord (pink, middle image, top centre) ends at the L2 level. The anaesthetic drug numbs (blocks) the bottom part of the spinal cord and the lower body areas that it enervates. This allows surgery (such as a Caesarean section) on a conscious patient. The further the anaesthesia reaches up the spinal cord, the higher the nerve block is on the body. A subarachnoid anaesthetic pierces the dura mater (spinal cord membrane). An epidural anaesthetic enters the extradural space.