PS263 Chapter Notes - Chapter 8: Zeitgeber, Cortisol, Circadian Clock
Document Summary
The body generates its own cycles of activity and inactivity. Animals" readiness for change in reasons comes partly from internal mechanisms. Birds generate a rhythm that prepares them for seasonal changes. Feeling sleepier and sleepier as the night goes on but as morning arrives we feel more alert, not less. Humans can do little to change natural 24 hour circadian pattern. Biologically driven circadian rhythm in our emotional well being and moods. Circadian rhythms may persist without light but light is critical for resetting them. Some blind people not sufficiently sensitive enough to secondary zeitgebers like noise and meals produce circadian rhythms longer than 24 hours. Disruption of circadian rhythms due to crossing time zones. Problems stem from mismatch between internal circadian clock and external time. Easier to adjust to crossing time zones going west than east b/c going west, we stay awake later at night and awaken late the next morning already partly adjusted.
