Across
- 6. slowly respond to light and slowly turn off when light is absent
- 7. rotates about every 24 hours
- 8. the pineal gland secrets this hormone to increase sleepiness
Down
- 1. a rhythm that occurs when no stimuli rest or alter the rhythm
- 2. region of the brain that serves as the biological clock, that maintains circadian rhythms to a 24 hr period
- 3. a stimulus that resets the circadian rhythm
- 4. input comes from a special population of retinal ganglion cells that have their own photopigment
- 5. neurons in the SCN are very active during the _______