PSYA01H3 Chapter 5: Psychology Notes Chapter 5.docx
Document Summary
Infradian rhythm: any rhythm that occurs for more than a day e. g. menstrual cycle: ultradian cycles: biological rhythms that occur more frequently, e. g. heart bear, urination, circadian rhythm: internally driven daily cycles of about 24 hours affecting physiological and behavioral processes, cells in the retina send messages about light levels to the scn (suprachiasmatic nucleus in the hypothalamus) which then communicates with the pineal gland, the pineal gland releases the hormone melatonin which is high at nighttime and this info about melatonin is sent back to the hypothalamus, there are 2 explanations for our 24 hour rhythms, entrainment: when biological rhythms become synchronized to external cues such as light, temperature or even a clock, time: we are influenced by the time because we are trained to believe to associate some times of the day with sleeping, endogenous rhythms: biological rhythms that are generated by our body that are independent of external cues such as light.
