Define Biological Clocks
processes that living organisms possess to keep time
The biological clocks in animals can be
molecular mechanisms (chemical reactions)
cellular networks of
communication (signaling systems)
Circadian rhythms
oscillations in physiology or behavior that occur with a
periodicity of about 24 hours
The molecular mechanisms
regulating biological clocks typically involve
transcription/translation feedback loop that controls the expression of clock genes and clock-controlled genes
what are the 4 principles of circadian rhythmicity
- The rhythm lasts approximately 24 hours (free-running period),
- The rhythm is endogenously generated (occurs in the absence of environmental cures),
- The rhythms are entrainable (their phase is set by some time giver, often light), and
- The rhythms are temperature compensated (their chemistry is not impacted by temperature).
Human Sleep Cycle
8 hrs/night
chronotype
the time your brain’s clock has you sleep
Proposed functions of sleep are
- Restoration (metabolic recovery)
- Cognition (memory consolidation)
what are larks ( morningness chronotype)
people who go to sleep early and wake up early in the morning
‘owls’ or eveningness chronotypes
people who to sleep late and wake up late
Human sleep is divided into
2 four hour blocks
Early stage of the sleep cycle is
considered deep sleep and these first 4 hours are associated with
slow-wave
electroencephalogram (EEG) brain activity.
Late stage of the sleep cycle is considered
shallow sleep and these 4 hours are associated wit
higher frequency EEG brain activity,
often associated with rapid eye movement (REM) sleep.
