Sleep wake cycle

Question 1

Sleep wake cycle

Answer 1

Our bodies are tuned into a 24 hour sleep wake cycle which is a regular circadian rythm

• Determined by an internal body clock located in the Hypothalamus
• This clock also regulates levels of arousal, metabolism, body temp and hormone secretions

Question 2

Circadian phase disorders:

Answer 2

Sleep disruption due to alteration of internal circadian rhythm,
Characterised by the inability to fall asleep or to remain asleep.

Question 3

Causes of circadian phase disorders:

Answer 3

Lifestyle factors 
Genetics 
Shift work 
Jetlag 
Adolescence etc.

Question 4

Circadian phase disorders can result in?

Answer 4

Insomnia and impairment in social and occupational functioning.

Question 5

Lifestyle factors…

Answer 5

Shiftwork
Stressful or low stress jobs 
Active or inactive lifestyle 
Diet and health (stimulants)
Good sleepers are more likely to have a more regular sleep routine than poor sleepers

Question 6

Genetics…

Answer 6

Studies found that identical twins have more similar sleep patterns than fraternal twins
Studies also suggest females need to sleep more than males

Question 7

Jetlag …

Answer 7

Change of time zones

West is best… gaining and losing time

Question 8

Adolescence and delayed sleep onset…

Answer 8

During adolescence the sleep/wake pattern shifts towards the evening (phase delay)
AKA Delayed sleep onset.
-Dangerous as adolescence need far more sleep than adults.

Question 9

Why does delayed sleep onset occur?

Answer 9

Melatonin, the hormone that helps induce sleep, is delayed in its release by two hours in adolescence.
Melatonin release is controlled by circadian rhythms but is also affected by light.
It is thought social factors can impact (homework, after school activities, internet).

Question 10

Treatment for Circadian phase Disorders is…?

Answer 10

Light Therapy,
can be used to re-set the body’s internal clock.
During light therapy, eyes are exposed to intense but safe amounts of light for a specific and regular amount of time. As artificial light can be used to affect the body clock in the same way that sunlight does.