Respiration is controlled by a respiratory centre located in the floor of the medulla oblongata of the brain. The centre is bilateral and its two halves are connected together by commissural neurons. The sides of this centre are connected with motor respiratory neurons. The nerve cells of the centre are connected with the breathing apparatus forming a reflex arc. These nerve cells are sensitive to chemical composition of blood. Half of the respiratory centre is an inspiratory centre and the other half is an expiratory centre. These two centres control the entire breathing in man with his knowledge about it. Dorsal respiratory group, ventral respiratory group and pneumotaxic groups act as respiratory centres in the brain.
