- Reflex action is the one which per- formed automatically and is not under the voluntary control of the brain. - Some examples of reflex action are: Knee jerk, movement of diaphragm, coughing, sneezing, yawning, blinking of eyes, immediately moving hand away on unknowingly touching hot plate, etc. - Spinal Cord is the controlling centre of a reflex action. In cases which don't require thinking only spinal cord is involved.