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?
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