Biologicak Rythems Flashcards
What are biological rhythms
They are our bodies process’ or behaviour in response to cyclical changes in the environment.
What are the two things that regulate our biological rhythms
-exogenous zeitgebers
-endogenous passmakers
What are exogenous zeitgebers
External factors in the environment that reset our biological clock eg light and dark
What are endogenous passmakers
The bodies Internal clock eg eyes detecting light even when closed
What are the 3 biological rhythms
-circadian rhythms
-infradian RhYthm
-ultradian rhythm
What is the circadian rhythm and what is it effected by
-occurs once a day eg sleep wake cycle
-balances our behaviour throughout the day
-effected by the exogenous zeitgebers (light) which sends info to our endogenous pass makers to detect.
The process of the sleep wake cycle
-Light is detected by our optic nerve even when shut - when there is no light an…
- electric impulse is sent to the SCN (master clock) which sends signal to
-pineal gland to increase melatonin which reduces brain activity helping you sleep.
-then in the morning when light is detected by the optic nerve the SCN sends a message to pineal gland to stop releasing melatonin.
Research into the SCN and how it supports role of SCN
-destroyed SCN of 30 chipmunks then put them back into their habitat.
-they had distrupted sleep wake cycle and after 80 days most had died.
-this is cause they were waking up and going round, looking for food when they shouldn’t be making them more exposed to predictors.
-supports the role of the SCN in maintaining our circadian rhythm (sleep wake cycle)
-the SCN helps our physiological and psychological well being
The cave study and positives of it.
Siffre
-spent 2 months in a cave total isolation with no clock, sun or calendar.
-replied on only endogenous passmakers no external zeitgebers (lighy)
-sleep wake cycle of 25-30 hours
✔️- RLA- showd night shift workers need time between changes to night and day shifts.
What is the infradian rhythm
-cycle that lasts longer than24 hours
-can be weekly,monthly,annually
-EG menstrul cycle,season affective disorder (SAD), hibernation
Explain the menstrul cycle
-the hormones oestrogen and progesterone regulate ovulation
-day one - the womb lining is shed 👶
-24-35 days
-rise in oestrogen and progesterone
-oestrogen - causes ovary to develop and relases egg 🥚
-progesterone- help women lining to thicken to prep for pregnant 🤰
Endocrine system acts as endogenous passmakers
Research support of infradian rhythm
-29 pregnant women with irregular cycles
- got the phenemone from the women’s sweat by cotton pad
-is then treated with alcohol and frozen then put on upper lip of other pp
-68% of women’s cycle became more similar to their Oder donors
-shows exogenous zeitgebers that influence infradian rhythm (menstrul cycle)
What is seasonal affective disorder (SAD) - infradian rhythm
And supporting research
-prone to depression in winter
-related to seasons
-longer nights in winter = increase melatonin in winter linked to higher levels of depression
-96 pp undergo bright light treatments
-got an hour and a half of bright light therapy in the morning and evening and after 3 weeks got better
What is ultradian rhythm
Cycle that’s under 24 hours
-stages of sleep
Explain the stages of sleep - ultradian rhythm
Each part of the cycle is characterised by different brain activity monitored using EEG.
stage 1+2- when you first drift off but can be easily woken. Light sleep, brainwave pattern starts to slow down.
stage 3+4- brain waves become slower, deep sleep, difficulty to Wake up
Stage 5 REM sleep- body is asleep but brain activity speeds up, when we dream, rapid eye movement but body is paralysed.
