Explain the Vasomotor Centre and Cardio-Inhibitory Centre
The vasomotor centre (in the medulla ablongata) excites the respiratory centre. The pulmonary ventilation is increased. The factors which stimulate respiration may excite the vasomotor centre simultaneously. Cardio-inhibitory (which restrains the action of heart) centre inhibits the respiratory centers. Hence, during respiration, heart rate and BP may vary. During inspiration, there is usually a rise in the heart rate and BP.