Ultradian Cycle

《英文msh词典》Ultradian Cycle
[入口词] Ultradian Cycle
[主题词] Activity Cycles
[英文释义] Bouts of physical irritability or movement alternating with periods of quiescence. It includes biochemical activity and hormonal activity which may be cellular. These cycles are shorter than 24 hours and include sleep-wakefulness cycles and the periodic activation of the digestive system.