Infradian Biological Rhythms Flashcards Preview

A2 Biopsychology AQA Psychology > Infradian Biological Rhythms > Flashcards

Flashcards in Infradian Biological Rhythms Deck (10):

Give an example of an Infradian Rhythm and explain why

Female menstrual cycle, regulated by monthly changes

one cycle lasting around 28 days


How many phases are in a single menstrual cycle and what are they largely controlled by?

4 key phases
endogenous pacemakers such as hormones


(Menstrual phase) As the lining of the uterus is shed, what does the hypothalamus stimulate?

The pituitary gland which releases follicle stimulating hormone.


(Follicular phase) what increases as the follicles in the ovary mature to ripen an egg?

Oestrogen levels


What happens as a consequence of increased FSH and Leutinising Hormone (LH) in the Ovulation phase?

An egg is released into the uterus


In the Lutial stage, what causes the uterus lining to be thickened for pregnancy and what happens if that does not occur?

Increased levels of progestrogen

LH, FSH and progestrogen decrease.


What evidence from Mc Clintock is there to suggest the influence of exogenous factors on the menstrual cycle?

29 iregular cycle females collected pheromones

rubbed on lips of other females

68% had changes to their cycle similar to their donor's


Female's pheromones act as..?

exogenous zeitgebers that influence the control of the cycle


What confounding variables can affect the menstrual cycle?

severe stress and malnutrition


It is likely that infrafian rhythms are controlled by a combination of endogenous and exogenous factors because?

Patterns of synchronisation could be due to due to those factors and can be expected to occur by chance