6.7: Infradian rhythms Flashcards
Infradian rhythm
An infradian rhythm is a type of biological rhythm with a frequency of more than 24 hours, such as menstruation and seasonal affective disorder
What is the female menstrual cycle governed by?
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
What time does the menstrual cycle refer to?
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though what is generally considered normal?
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal.
The menstrual cycle could be how many days?
The menstrual cycle could be 20 - 60 days
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal.
The menstrual cycle could be 20 - 60 days.
What is the menstrual cycle controlled by?
The menstrual cycle is controlled by the female hormones oestrogen and progesterone, which are released by the endocrine glands
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal.
The menstrual cycle could be 20 - 60 days.
The menstrual cycle is controlled by the female hormones oestrogen and progesterone, which are released by the endocrine glands.
During each cycle, what do rising levels of oestrogen do?
During each cycle, rising levels of oestrogen cause the ovary to develop an egg and release it (ovulation)
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal.
The menstrual cycle could be 20 - 60 days.
The menstrual cycle is controlled by the female hormones oestrogen and progesterone, which are released by the endocrine glands.
During each cycle, rising levels of oestrogen cause the ovary to develop an egg and release it (ovulation).
After ovulation, what does progesterone do?
After ovulation, progesterone helps the womb lining to grow thicker, readying the body for pregnancy
The female menstrual cycle is governed by monthly changes in hormone levels that regulate ovulation.
The menstrual cycle refers to the time between the first day of a woman’s period, when the womb lining is shed, to the day before her next period.
The typical cycle takes approximately 28 days to complete, though anywhere between 24 and 35 days is generally considered normal.
The menstrual cycle could be 20 - 60 days.
The menstrual cycle is controlled by the female hormones oestrogen and progesterone, which are released by the endocrine glands.
During each cycle, rising levels of oestrogen cause the ovary to develop an egg and release it (ovulation).
After ovulation, progesterone helps the womb lining to grow thicker, readying the body for pregnancy.
If pregnancy does not occur, what happens?
If pregnancy does not occur, the egg is absorbed into the body and the womb lining comes away and leaves the body (the menstrual flow)
Although the menstrual cycle is an endogenous system, what does evidence suggest?
Although the menstrual cycle is an endogenous system, evidence suggests that it may be influenced by exogenous factors, such as the cycles of other women
McClintock and Stern demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles, via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up.
The pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were given a pad from the second day of the cycle and so on.
McClintock found that 68% of women experienced changes to the cycle which brought them closer to the cycle of their ‘odour donor.’
This shows that the menstrual cycle of a woman can be altered by communication via pheromones.
Evaluation:
The effects of pheromones can help explain menstrual synchronicity, whereby groups of women who live together, such as nuns, have menstrual cycles that can become synchronised with each other.
The idea of communication via pheromones can effectively explain this phenomenon, as there must be something in the shared environment that acts as a zeitgeber.
It is suggested that there is an evolutionary advantage if this occurs, as it means there could potentially be synchronised pregnancies and that means that childcare could be shared when the babies are born at or around the same time.
However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
The extent to which pheromones can have an effect still requires research.
Wilson (1992) challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.
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Seasonal affective disorder (SAD)
Seasonal affective disorder (SAD) is a depressive disorder which has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5
Seasonal affective disorder (SAD) is a depressive disorder which has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
As with other forms of depression, what are the main symptoms of SAD?
As with other forms of depression, the main symptoms of SAD are persistent low mood alongside a general lack of activity and interest in life
Seasonal affective disorder (SAD) is a depressive disorder which has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
As with other forms of depression, the main symptoms of SAD are persistent low mood alongside a general lack of activity and interest in life.
Why is SAD often referred to as the winter blues?
SAD is often referred to as the winter blues, because the symptoms are triggered during the winter months when the number of daylight hours becomes shorter
Seasonal affective disorder (SAD) is a depressive disorder which has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
As with other forms of depression, the main symptoms of SAD are persistent low mood alongside a general lack of activity and interest in life.
SAD is often referred to as the winter blues, because the symptoms are triggered during the winter months when the number of daylight hours becomes shorter.
SAD is a particular type of infradian rhythm called a what?
SAD is a particular type of infradian rhythm called a circannual rhythm