Biological Rhythms Flashcards
(13 cards)
What is a biological rhythms?
A change in the body processes/ behaviour in response to cyclical changes within the environment
3 main categories of biological rhythm?
Around 24 hours e.g. sleep-wake cycle= circadian
Less than 24 hours e.g. sleep stages= ultradian
More than 24 hours e.g. SAD= infradian
What is circadian?
Around 24 hours e.g. sleep wake cycle
What is ultradian?
Less than 24 hours e.g. sleep stages
What is infradian?
More than 24 hours e.g. SAD
What are all biological rhythms regulated by?
Endogenous pacemakers and exogenous zeitgebers
What is an endogenous pacemakers?
The bods internal body clock that regulates biological rhythms
What is an exogenous zeitgeber?
External factors in the environment which reset our biological clocks
What is an example of an endogenous pacemakers?
SCN detects light even when eyes are closed
SCN then uses this information to coordinate the activity of the entire circadian system by either triggering sleep or telling the body to wake up
What is an example of an exogenous zeitgeber?
Light, social cues (brushing your teeth before bed)
How does melatonin play a role in triggering sleep?
Responds to a decrease in the levels of light
When does melatonin secretion correlate with increased feeling of sleepiness?
About 2 hours before someone’s regular bedtime
Therefore it is very difficult for sleep to occur before this 2 hour window
What happens once melatonin has been secreted?
There is a point at which the “sleep gate” opens and sleep is inevitable- known as a hypnagogic state
