6C: Regulation of sleep-wkae patterns

Question 1

What are biological rhythms?

Answer 1

Repeated biological processes that are regulated by internal mechanisms

Biological rhythms include various cycles, such as circadian and ultradian rhythms.

Question 2

Define circadian rhythms.

Answer 2

Biological and behavioural changes that occur as part of a cycle that lasts around 24 hours

Circadian rhythms influence sleep-wake cycles, hormone release, and other bodily functions.

Question 3

What is the sleep-wake cycle?

Answer 3

A 24-hour-cycle that is made up of time spent sleeping and time spent awake and alert

The sleep-wake cycle is a key component of circadian rhythms.

Question 4

What are ultradian rhythms?

Answer 4

Biological and behavioural changes that occur in a cycle that lasts less than 24 hours

Ultradian rhythms can include cycles of alertness and sleep stages.

Question 5

What is REM sleep?

Answer 5

A type of sleep characterised by rapid eye movement, high levels of brain activity, and low levels of physical activity

REM sleep is crucial for memory consolidation and emotional regulation.

Question 6

What is NREM sleep?

Answer 6

A type of sleep characterised by a lack of rapid eye movement and is subdivided into three different stages

NREM sleep is important for physical restoration and recovery.

Question 7

Define sleep episode.

Answer 7

The full duration of time spent asleep, from falling asleep until waking up

Sleep episodes can vary in length and quality.

Question 8

What is a sleep cycle?

Answer 8

A repeated approximate 90-minute period in which an individual progresses through stages of REM and NREM (stages 1–3) sleep

Each complete sleep cycle typically includes both REM and NREM stages.

Question 9

What is the role of the suprachiasmatic nucleus (SCN)?

Answer 9

An area of the hypothalamus that is responsible for regulating an individual’s sleep-wake patterns

The SCN responds to light cues to help maintain circadian rhythms.

Question 10

What does the pineal gland do?

Answer 10

A gland in the brain responsible for the production and release of melatonin

The pineal gland plays a key role in regulating sleep-wake cycles.

Question 11

What is melatonin?

Answer 11

A hormone released by the pineal gland typically at night-time to induce sleep as part of the sleep-wake cycle

Melatonin levels rise in the evening and fall in the morning.

Question 12

What is cortisol?

Answer 12

A hormone that is responsible for increasing alertness and maintaining heightened arousal

Cortisol levels typically peak in the morning and decrease throughout the day.