Jet Lag and Shift Lag Flashcards
How can jet lag and shift lag affect sleep and wake patterns?
because the circadian system is intolerant of any major alterations in the sleep/wake patterns because this causes the biological clock to become completely out of balance.
What is jet lag?
The term for the effects we experience after crossing into a different time zone. Its estimated that our SCN takes several cycles to entrain to a new environment.
What are the symptoms of jet lag?
disturbed sleep - insomnia, early waking or excessive sleeping
daytime fatigue
difficulty concentrating
What are the two different kinds of adjustment our body clocks can make when crossing time zones?
phase advance
phase delay
What is phase advance?
travelling west to east
shortens your day
What is phase delay?
travelling east to west
extends your day
What is easier to adjust to: phase advance or phase delay?
phase delay
What is shift lag?
the term for the negative effects on workers, caused by rotating shifts; and in particular by working night shifts
Why does working night shifts emphasises the effects of shift lag more?
working at night requires you to be alert at all times when you are used to being asleep, and vice versa
This means your natural rhythms will be out of synchronisation with most of the available cues from external zeitgebers
What are the effects of shift work?
Knutsson et al found that individuals who worked shifts for more than 15 years were three times more likely to develop heart disease than non-shift workers.
one main effect is the difficulty in sleeping during the day for night shift workers
many of the most catastrophic industrial accidental in history (e.g. chernobyl) occurred at night, and were caused by human error - suggesting night shift work impairs concentration and judgement
