Sleep cycle help?Watch
3.1.4 The role of internal pacemakers (body clock) and external zietgebers in the regulation of the circadian sleep-wake cycle.
3.1.5 Infradian rhythms including the menstrual cycle and seasonal affective disorder and therapies, including light therapy.
3.1.6 Research into the circadian sleep-wake cycle and infradian rhythms
But none of this is in my textbook so I'm worried about what kind of questions they'll ask on the paper. My textbook is the AS/AL textbook by Karren Smith. Where do I find all these things? :/