Reflex Action - GCSE Biology Definition

A reflex action is a quick and automatic response to a stimulus that does not involve the conscious part of the brain. It helps protect the body from harm by allowing it to react rapidly to danger. For example, if you touch something hot, sensory neurones send a signal to the spinal cord, which immediately sends a message through motor neurones to the muscles in your hand, causing it to pull away. This happens before you are aware of the pain. Reflex actions are also important for everyday functions such as blinking and breathing.