endocrinology part 3 Flashcards
circadian rhythm is produced by what?
Hypothalamus
What is the circadian rhythm?
daily variations in physiological parameters
intrinsic circadian clock in sync with light/dark cycles
influences activity, body temp, hormones, metabolism, sleep/wake, feeding
the retina projects to what brain region that is associated with the circadian rhythm?
The superchiasmatic Nucleus (SCN)
what happens to rats if there is constant darkness
still have a 12 hour rhythm - gave evidence to an internal clock
What happens if they removed the SCN in rats?
The circadian rhythm was disrupted, very short naps but activity was distributed all though out the day and night
What happens if you are in constant dark for many months?
will lose circadian activity
What controls internal clock?
SCN
during the day what proteins are expressed?
CLOCK/BMAL1
Transcription factors that are a heterodimer
bound together to become active
What does CLOCK/BMAL1 bind to during the day?
Per1,Per2
Cry1,Cry2
Reverb alpha
will stimulate these throughout the day
What inhibits BMAL1?
Reverb alpha
What hetrodimer is active during the night?
Period/Cryptochrome
period and cryptochrome at as what?
repressors
When is BMAL1 repressed?
during the day
during the night what inhibits the CLOCK?BMAL1 heterodimer?
The PER/CRY heterodimer
