Sleep Flashcards
What theories are there considering why we need sleep?
1) . Restoration –> rest and repair.
2) . Energy conservation –> sleep and save calories.
3) . Brain processing –> memory consolidation, synaptic strengthening.
How many hours is the sleep cycle?
24-25.
What happens if you disrupt the sleep cycle?
Insufficient sleep can affect =
- behaviour.
- reducing performance.
- increase the risk of accidents.
What are the 2 states of sleep?
1) . REM.
2) . NREM.
How is brain changes in sleep measured?
Electroencephalogram (EEG) scans.
What is REM sleep?
- Occurs every 90 mins.
- Lasting 5-30 mins.
- Dreaming.
- Heart and respiratory rates are irregular.
- 4-5 cycles per night.
What is NREM sleep?
- Reduction in physiological activity.
- Breathing and heart rate slow down.
What physiological changes are there as sleep gets deeper (NREM)?
Brain waves get slower and have a greater amplitude.
What is a circadian rhythm?
Bodily changes in a 24-hour cycle.
What fluctuations in the body vary via a circadian rhythm?
- Hormone secretion.
- Body temperature.
What factors affect sleep?
- Mealtimes.
- Work patterns (night shift).
What internal factors affect sleep?
- Core body temperature.
- Urine volume.
- Cerebral blood flow.
- Systolic pressure.
- Melatonin.
- Cortisol.
- Thyrotrophin.
- Growth hormone.
Which endocrine gland responds to light?
Pineal.
What works in conjunction with the pineal gland to secrete melatonin?
Suprachiasmatic nucleus (SCN).
What stimulates the secretion of melatonin from the pineal gland?
Darkness =
- light inhibits secretion.
