Biological Rhythms

Question 1

Circadian Rhythm

Answer 1

• a biological cycle with a duration of approximately 24 hours
• driven by environmental signals - zeitgebers ie. changes in light levels
  e.g. sleep-wake cycle

Question 2

Suprachiasmatic Nucleus

Answer 2

• analyses strength and duration of light (via retina) and sends signals to pineal gland which regulates release of melatonin
• regulates the sleep-wake cycle
• located in the hypothalamus

Question 3

Ultradian Rhythm

Answer 3

• biological rhythm that occurs within 24 hours
  e.g. NREM/REM cycle