sleep and circadian rhythms Flashcards
changes of sleep duration across the lifespan neonates
neonates - 16 hours sleep
more rapid eye movements
children
10 hours sleep
adolescents
8.5 hours of sleep
adults
6 hours
why do we sleep
repair of all types if cells eg Brian cells
rest our eyes
retain info
energy conservation
restoration and recovery of body systems- immune function
memory consolidation
consolidating new memories - allows brain to forget random unimportant info
sleep deprivation affects
memory attention speed
sleep deprecation is also associated with
reduced emotional intelligence
reduced social skills and reduced self confidence
teenagers with set bedtimes are
less likely to suffer depression / suicidal thoughts
neuroimaging of emotional processing after sleep deprivation
more amygdala activation , less coupling of activation of amygdala and prefrontal cortex, more negative emotional and less prefrontal control
short sleep is also a risk factor for being
overweight- increase appetite
REM
rapid eye movements
very active - muscles are parlayed by pons
strong activation if amygdala
REM dreams state
more vivid , emotional , negative dreams
why is the body paralysed during REM sleep
pons parlays the muscles
NREM sleep
light sleep and deep sleep
light sleep
not very restoring, quick waves - strong brain activation , relatively strong muscle tone
deep sleep
slow wave sleep - very restoring - brings brain to the share in which It is able to process info and learn
low muscle tone
NREM dreams
less often remembered and less vivid / emotional
two process model of sleep regulation
sleep pressure and circadian processes
sleep pressure
homeostatic - dependent on how long one has been without sleep
longer we’ve been awake the more sleep pressure- tired
circadian process
oscillating refused by the body clock
sleep pressure then learning
synapse size increases - Brin plasticity - stronger but cannot grow infinitely
amount of deep sleep is a sign of the
strength of sleep pressure
circadian process- oscillating
swinging back and forth between sleep promoting and sleep preventing processes
due to the circadian processes
sometimes its very difficult to fall asleep
circadian process regulates the
timing of sleep and results in the 24 hour rhythm
without cycle/ circadian process we might
sleep for instances of 3 hours within every 8 hours
biological basis of process c
body clock located in the SCN - modulation of circadian rhythms of more than 100 body functions
role of the SCN experiment
hamsters - normal SCN (24 hour rhythm) or damaged SCN.
donor hamster - 22 hours
role of zeitgeists for circadian rhythms
body clock of SCN is only approximately 24 hours
entrainment
Zeitgeber entrain the clock - sets the clock according to the 24 hour rhythm od the outside world
Zeitgeber supports the process of
synchronisation of the peripheral bodily clocks
exogenous zeitigeres
external cues light , timing, intensity , physical activity
light helps regulate
internal biological clocks - resets the clock
SCN contains
receptors that are sensitive to light
melanopsin protein is
sensitive to light - carries signal to the SCN to set the 24 hour daily body cycle
