Biological rhythms: infradian rhythms Flashcards
infradian rhythm definition
type of biological rhythm with a frequency of less than one cycle in 24 hours (takes more than a day) such as menstruation and seasonal affective disorder
type of brainwave in stage 1
alpha waves
type of brainwave in stage 2
alpha and sleep spindles
type of brainwave in stage 3 and 4
delta waves
type of brainwave in stage 5 (REM sleep)
theta waves
what type of biological rhythm is the menstrual cycle
infradian rhythm
what is menstrual cycle governed by
monthly changes in hormone levels which regulate ovulation
what does the menstrual cycle refer to
time between the first day of a period (when womb lining is shed) to the day before the next period
how long does menstrual cycle take
typically 28 days (but form 24-35 days is considered normal)
what happens during the menstrual cycle
rising levels of the hormone oestrogen causes the ovary to develop an egg and release it (ovulation). after ovulation the hormone progesterone helps the womb lining to grow thicker which causes the womb to be ready for pregnancy which is does not occur, the egg is absorbed into the body, the womb lining comes away and leaves the body (menstrual flow)
is the menstrual cycle endogenous or exogenous
endogenous system but can be influenced by exogenous factors
what are the exogenous factors that can effect the menstrual cycle
cycles of other women –> pheromones
Stern and McClintock study
how menstrual cycles may synchronise as a result of the influence of pheromones
when did Stern and McClintock research
1998
Stern and McClintock sample
29 women with a history of irregular periods