The human nervous system

The human body has a nervous system that enables us to sense and respond quickly to changes outside and inside the body. Examples of stimulus (e.g. increase in temperature) and response (e.g. sweating). The structures that make up the central nervous system (CNS) and peripheral nervous system (PNS). Receptors detect stimuli; they can be single cells (e.g. in the skin) or groups of cells in sense organs (e.g. the eye). Sensory neurones join receptors to the CNS; motor neurones join the CNS to effectors that carry out the response.