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
