Infradian Rhythms

Cards (21)

  • What is an Infradian rhythm?
    A biological rhythm lasting longer than 24 hours
  • How is the menstrual cycle regulated?
    By monthly changes in hormone levels
  • What does the menstrual cycle refer to?
    The time from the first day of a period to the next
  • How long does a typical menstrual cycle take?
    Approximately 28 days
  • What hormone increases during the menstrual cycle to cause ovulation?
    Oestrogen
  • What role does progesterone play after ovulation?
    It helps the womb lining grow thicker
  • What happens if pregnancy does not occur after ovulation?
    The egg is absorbed and the womb lining sheds
  • What is the term for external cues that may influence biological rhythms?
    Exogenous zeitgebers
  • What did the study by Stern and McClintock (1998) investigate?
    How menstrual cycles may sync due to pheromones
  • How were pheromones collected in the Stern and McClintock study?
    Using cotton pads placed in armpits
  • What percentage of women experienced changes to their cycle in the study?
    68%
  • What does the conclusion of the Stern and McClintock study suggest?
    Women living close may synchronize cycles
  • What is a chemical substance that affects behavior or physiology called?
    Pheromones
  • What is Seasonal Affective Disorder (SAD)?
    A depressive disorder with a seasonal pattern
  • What triggers the symptoms of SAD?
    Shorter daylight hours
  • What type of infradian rhythm is SAD classified as?
    A circannual rhythm
  • What hormone is thought to be implicated in SAD?
    Melatonin
  • How does melatonin secretion change in winter?
    It continues for longer due to less light
  • What effect does prolonged melatonin secretion have on serotonin?
    It affects serotonin production linked to depression
  • What are the evaluations regarding menstrual cycle synchronization?
    • Evolutionary advantage for childcare sharing
    • Jeffery Schank (2004) questions validity
    • Competition may lower offspring fitness
    • McClintock's research has confounding variables
  • What are some confounding variables that could alter a woman's cycle?
    Stress, diet, and exercise