Homeostatic feedback mechanisms that regulate the ventilatory pattern of respiration involves the medulla and the pons. The pons are divided into two groups to perform their role. First, the pneumotaxic center sends signals that inhibit inspiration by limiting the activity of the phrenic nerve. As a result, the signals of the apneustic center and the tidal volume decreases. Secondly, the apneustic center signals inspiration for deep and long breaths. This region controls the intensity of breathing. The stretch receptors of the pulmonary muscles inhibit the apneustic center at the maximum depth of inhalation. Thus, the apneustic center increases tidal volume. The medulla has two functional regions as well. The first part, ventral respiratory compartment, stimulates expiratory movements, while the dorsal respiratory region triggers inspiratory movements. Majorly, the medulla oblongata is the main respiratory control part that sends signals to the muscles that control breathing to initiate respiration.