Infradian Rhythms Flashcards
Infradian rhythms
Are biological rhythms that lasts longer than 24 hours
example is the female menstrual cycle
Operates on a 28-35 day cycle and the rhythms is regulated by glands and hormones
What are infradian rhythms influenced by ?
Endogenous and exogenous factors
Start of the cycle
Begins on the first day of a women’s period when womb lining is shed
Pitrutitary gland releases FSH which activates the release of oestrogen from ovaries and causes egg to mature
Middle of a cycle
Increase of oestrogen increases levels of LH which promotes the release of an egg
Oestrogen develops lining of womb and progesterone helps it grow thicker readying the womb for pregnancy
End of cycle
If pregnancy does not occur egg is absorbed in body womb lining comes away
Cycle begins again
What is the menstrual cycle mainly ?
An endogenous system , regulated by the pitruitrary gland
Can be affected by exogenous factors such as light stress and pheromones ( chemical scents given off by males and females )
Ao3 research to contradict infraidan rhythms such as mentruals cycle mainly governed by endogenous system by russel
Asked sample of women to wear cotton pads under there arm
Pads were rubbed on upper lip of 5 s inactive women
Process repeated daily for five months
4/5 women menstrual cycle that synchronised within one day
Shoes IR such as menstrual cycle can be affected by exogenous factors as well
Reduces validity of role of EP in regualting IR and emphasises importance of interaction with EZ
Russell Ao3 research into effect of EZ low control over extraneous variables
Field experiment and so low control over extraneous variables
Took part in participants natural environment
Where other exogenous factors such as light or changes in diet or stress could have affected the infradian rhythm
Difficult to establish cause and effect between influence on pheromones on maintaining infradian rhythms
Weakens extent to which russels research contradicts importance of EP on mainiting IR
Ao3 role of Ez In IR such as pheromones can be explained by evolutionary psychologisits
Would have been advantagous in evolutionary past for social group to sychronise pregnancies
So many women would be breast feeding at same time
So one mother could take over caring for orphaned child
Show EZ are important in maintaining IR to enchance survival chances
Showing importance of interaction of endogenous and exogenous factors in IR
