Bodily Rhythms

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Bodily Rhythms

• Endogenous pacemakers
• The internal body clocks that generate
  biological rhythms
• Exogenous zeitgebers
• External factors that regulate or alter
  biological rhythms

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2
The Menstrual Cycle
Ovaries Uterus
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3
The Menstrual Cycle
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4
The Menstrual Cycle
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Adams et al (1979)
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The Menstrual Cycle

• Generated by the hypothalamus
• Fluctuations in hormone levels affect
• Internal biology (ovulation, menstruation)
• Sexual behaviour (optimal for conception)
• Apparently influenced by zeitgebers
• Possible pheromonal mechanism
• Possible evolutionary advantage

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