7b

Question 1

What are sleep disorders?

Answer 1

Sleep disorders are disturbances to typical sleeping and waking patterns.

Question 2

What are circadian rhythm sleep disorders.

Answer 2

These are sleep disorders that interfere with the typical regulation of the circadian rhythm of sleep, leading to a change in the sleep-wake cycle.

Question 3

Causes of circadian rhythm sleep disorders.

Answer 3

Circadian rhythm sleep disorders are fundamentally caused by a disruption to the typical sleep- wake cycle. This can be due to a biological issue, such as the sleep-wake shift that occurs in adolescence , or lifestyle changes, such as shift work.

Question 4

Effects of circadian rhythm sleep disorders.

Answer 4

Circadian rhythm sleep disorders tend to result in an individual experiencing some form of sleep deprivation. Thus an individual may experience:
- Amplified emotional responses.
- Fatigue.
- Irritability.

Circadian rhythm sleep disorders can also result in individual struggling to keep up or maintain social commitments, such as waking and up and attending school early.

Question 5

What is a delayed sleep phase syndrome (DSPS)? Give an example.

Answer 5

This is a circadian rhythm sleep disorder in which sleep and waking occur later than usual. For example, if an individual typically sleeps at 10 pm and wakes up at 8am, with DSPS they may instead sleep at 1am and wake up at 12pm.

Question 6

How is DSPS caused?

Answer 6

DSPS is caused by the misalignment between internal and external cues that regulate the circadian rhythm. Specifically, external cues are received at an appropriate time, but internal cues are not.

Question 7

Give an example of how DSPS is caused.

Answer 7

For example, an individual may receive the external cues for light during the day, and darkness at night, but they do not receive internal cues at an appropriate time. This may cause melatonin production to occur later, and thus an individuals sleep and wake time occurs later than appropriate.

Question 8

What is an advanced sleep phase disorder (ASPD)? Give an example.

Answer 8

A type of circadian rhythm sleep disorder in which sleeping and waking occur earlier than usual. For example, if an individual typically sleeps at 10pm and wakes up at 8am, with ASPD they may sleep at 7pm, and wake up at 5am.

Question 9

Whats a difference between an advanced sleep phase disorder and a delayed sleep phase disorder?

Answer 9

With an advanced sleep phase disorder, melatonin secretion occurs earlier than usual, whereas with a delayed sleep phase disorder, melatonin secretion occurs later than usual.

Question 10

What is shift work?

Answer 10

Shift work involves working at unusual times, such as working over night.

Question 11

What are some examples of shift work?

Answer 11

It can involve rotating shift work, which can involve working a week of morning shifts, followed by a week of night shifts.

Question 12

How does shift work impact an individuals sleep-wake cycle?

Answer 12

Shift work can impact an individuals sleep-wake cycle, as their circadian rhythm is constantly changing and adapting to a new environment.

Question 13

Is shift work a sleep disorder or a cause of sleep disorders?

Answer 13

Shift work is a cause of sleep disorders.

Question 14

What are some effects of shift work?

Answer 14

• Insomnia (falling asleep and staying asleep).
• Affecting quality and quantity of sleep.
• Fragmented sleep (sleeping at unusual hours).

Question 15

Whats the difference between ASPD/DSPS and shift work?

Answer 15

The difference between these is that ASPD and DSPS are caused by problems with internal cues (melatonin secretion), whereas shift work related disorders are caused by external cues, such as having to be awake when its dark and asleep when its light.

Question 16

What is bright light therapy?

Answer 16

Bright light therapy is a method used to adjust a persons circadian rhythm, through exposure to a high intensity light source.

Question 17

Why is bright light therapy used?

Answer 17

To adjust a persons circadian rhythm, so that their sleep and wake time are more appropriate.

Question 18

How will the method of bright light therapy be used for a delayed sleep phase syndrome?

Answer 18

A person with DSPS will be exposed to the bright light in the morning. The suprachiasmatic nucleus will be signalled, promoting wakefulness through the release of cortisol. This will then trigger an earlier release of melatonin at night time by the pineal gland.

Question 19

What makes bright light therapy effective?

Answer 19

• Appropriate timing of exposure sessions: bright light therapy must occur at the right time, in order to make a person feel awake at the same time.
• The right amount of light: the intensity of the light and the length of the exposure must be appropriate to the persons disorder and the desired changes to the circadian rhythm.
• Safe exposure: a person must not directly look at the light, and their face should be an adequate distance away from the light source.

Question 20

Bright light therapy for DSPS

Answer 20

• An individual is exposed to bright light earlier in the morning or appropriate waking time.
• This will act as an external cue to the SCN, and promote wakefulness through sending signals to release cortisol.
• This will therefore allow the SCN to send signals to for the secretion of melatonin at a more appropriate time.

Question 21

Bright light therapy for ASPD

Answer 21

• An individual is exposed to bright light later on in the evening, when feeling sleepy.
• This will act as an external cue to the SCN to promote wakefulness.
• This will then help the SCN to send signals at a later more appropriate time for the release of melatonin, enabling an individual to stay awake throughout the day and fall asleep at a more appropriate time.