Circadian Rhythms - BIOPSYCHOLOGY Flashcards
what are biological rhythms
recurring patterns of behaviour in the body’s systems (long-term)
examples of biological rhythms
endocrine system, immune system
what are circadian rhythms
a pattern or cycle that lasts around a day (short-term)
how have human circadian rhythms been affected by evolution
evolutionary pressure on rhythms included avoiding predators and repair/recovery/growth
like many organisms, what does our biological clock respond to
sunlight
cycle to wake (starting at sunlight)
sunlight –> photoreceptor (retina) –> SCN (hypothalamus) –> intense/ blue light –> cortisol (pituitary) –> wake
cycle to sleep (starting at sunlight)
sunlight –> photoreceptor (retina) –> SCN (hypothalamus) –> faint/ red light –> melatonin (pineal) –> sleep
what occurs at 2am
deepest sleep
what occurs at 4:30am
lowest body temperature
what occurs at 6:45am
sharpest blood pressure rise
what occurs at 7:30am
melatonin secretion stops
what occurs at 2:30pm
best co-ordination
what occurs at 3:30pm
fastest reaction time
what occurs at 5pm
greatest cardiovascular effiency and muscle strength
what occurs at 6:30pm
highest blood pressure
what occurs at 7pm
highest body temperature
what occurs at 9pm
melatonin secretion starts
pineal gland function in circadian rhythms
converts serotonin to melatonin and ‘puts us to sleep’
pituitary gland function
releases hormones to control other glands, the ‘master gland’
hippocampus function
associated with STM - episodic buffer
somatosensory cortex function
sensory information - creates ‘sensations’ (mostly touch)
motor cortex function
voluntary movement
