Final answer:
The two centers that control heart rate are the cardioaccelerator centers and the cardioinhibitory centers. The cardioaccelerator centers stimulate cardiac function, while the cardioinhibitory centers slow it down.
Step-by-step explanation:
The two centers that control heart rate are the cardioaccelerator centers and the cardioinhibitory centers.The cardioaccelerator centers stimulate cardiac function by regulating heart rate and stroke volume via sympathetic stimulation from the cardiac accelerator nerve.
The cardioinhibitory centers slow cardiac function by decreasing heart rate and stroke volume via parasympathetic stimulation from the vagus nerve.