Biological Rhythms: Infradian And Ultradian Rhythms Flashcards
(42 cards)
What is the menstrual cycle an example of?
Infradian rhythms
What does the menstrual cycle refer to?
The time between the first day of a woman’s period to the day before her next period
How long does the typical menstrual cycle take to complete?
28 days
During each menstrual cycle what causes the ovary to develop an egg and release it?
The hormone Oestrogen
What happens after ovulation?
The hormone progesterone helps the womb lining grow thicker, readying the womb for pregnancy
What happens if pregnancy doesn’t occur?
The egg is absorbed into the body, the womb lining comes away and leaves the body
What type of system is the menstrual cycle?
Endogenous system
What does evidence suggest the menstrual cycle may be affected by?
Exogenous factors e.g. other woman’s cycles
What did Stern and McClintocks’ study show?
How menstrual cycles may synchronise as a result of the influence of pheromones
What did Stern and McClinton study?
29 women with a history of irregular period
What was gathered from the 9 women?
Pheromones by a cotton pad placed under there armpit
How long were the cotton pads worn?
For at least 8 hours to ensure the pheromones were picked up
What were the pads treated with?
Alcohol and frozen to be rubbed on the upper lip of another participant
What happened on day 1?
Pads from the start of the menstrual cycle were applied to all 20 women
What happened on day 2?
Everyone was given a pad from the second day
What did Stern and McClinton find?
68% of women experienced changes to their cycle which brought them closer to the cycle of their ‘odour donor’
What is Seasonal Affective Disorder?
A depressive disorder which has a seasonal pattern of onset
What are the main symptoms of SAD?
Persistent low mood, lack of activity and interest in life
When are the symptoms of SAD triggered?
During the winter months when the number of daylight hours becomes shorter
What type of Infradian rhythm is SAD?
Circannual rhythm
What other type of rhythm can SAD be classed as?
Circadian rhythm
What have psychologists hypothesised?
The hormone melatonin is implicated in the cause of SAD
What happens during the night?
The pineal gland secretes melatonin until dawn when there is an increase in light
What happens during winter?
The lack of light in the morning means this secretion process continues for longer this is thought to have a knock on effect on the production of serotonin in the brain