E do pace,Akers and exogenous zeigbers - sws

• How can social cues help circadian rhythms?

  A good way to entrain circadian rhythm to new time zone when travelling is to follow social cues of that culture e.g. meal times, bed times etc!
• What is biological rhythms regulated by ?

  Endogenous pacemakers and exogenous zeitgebers 
• What do endogenous pacemakers govern ?

  Internal mechanism that govern biological rhythms e.g the circadian sleep wake cycle 
• What do endogenous pacemakers govern ?

  Internal mechanism that govern biological rhythms e.g the circadian sleep wake cycle 
• Where does the SCN lie?

  It’s in the hypothalamus which is the main endogenous pacemaker which controls other biological rhythms and other areas of the brain e.g pineal gland which is responsible for   sleep + arousal 
• What other information does the SCN receive 

  -light levels from the optic nerve which sets the circadian rhythm so that it’s in synchronisation from the outside world e.g day + night 
• What did Morgan do to hamsters?

  -Hamsters bred with 20 hour SCN circadian rhythm

  -SCN neurons from ‘abnormal’ hamsters transplanted to

  ‘healthy’ hamsters.

  -The Hampstead displayed the same abnormal circadian rhythm of 20 hours showing that the transplant SCN had imposed its pattern onto the hamsters