Sleep Flashcards
How is sleep defined?
Sleep remains the only universal behaviour known to biology with no clear consensus regarding a fundamental underlying function.
What do the different volumes of sleep mean about the animal?
The safer the animal feels the more sleep they have. Vulnerable animals will sleep very little and be easily aroused.
How long will a dolphin or whale stay awake for after giving birth?
24 hours a day for the first couple of weeks while the baby is particularly vulnerable.
How long will male sandpipers stay awake during spring breeding season?
active up to 23hours a day for nearly 3 weeks.
What is the function of hibernation?
Conserving energy while food is scarce.
What physiological things happen to an animal during hibernation?
Heart rate decreases and dendrites lose almost a quarter of their branches.
What is unihemispheric sleep?
One hemisphere (and the opposite eye) sleeps while the other remains awake.
What animals does unihemispheric sleep occur?
Aquatic mammals e.g. dolphins and many birds, and some reptiles.
What sleep waves occur during unihemispheric sleep?
Only slow-wave sleep (not REM sleep) occurs.
What is the inactivity theory?
The adaptive or evolutionary theory. Suggests inactivity at night helped animals survive as they did not injure themselves in the dark and were not killed by predators. This was therefore a trait passed on through natural selection.
What is a limitation of the inactivity theory?
Its always safest to be conscious, even if lying still in the dark.
What is the energy conservation theory?
Food is not always easy to come by, so an animal must conserve its energy. This is especially important during the night when it may be harder to find food.
What support is there for the energy conservation theory?
Support: energy metabolism is reduced during sleep (10% in humans and more in other species).
What limitations are there for the energy conservation theory?
Animals engaging in unihemispheric sleep are still using up energy.
What is the Restorative Theories?
During sleep there is restoration of what has been lost from the body whilst awake (e.g., muscle mass, tissue cells).
What support is there for the restoration theory?
Many major restorative functions (e.g., muscle growth, tissue repair) occur mainly in sleep.
What is the brain plasticity theory?
Sleep is a time in which the brain develops and changes i.e. creating new neurone and pruning old connections.
What support is there for the brain plasticity theory?
Sleep appears to be crucial for initial brain development in infants. Extensive research to suggest improvement in cognitive function (especially memory) following sleep.
What is circadian rhythms?
The human biological clock - like that of most organisms - synchronises to the Earth’s 24 hour rotation using signals from the environment, known as zeitgebers (time-giver).
Light is the strongest zeitgeber, although social cues also have an influence e.g. getting used to waking up at certain times.
Circadian rhythms: What will happen to your body in the morning when not slept all night?
After an entire night without sleep you will still begin to feel more alert in the morning when it becomes light.
Circadian rhythms: When there is no reason to wake at a specific time, what happens to peoples waking times in e.g. Germany?
People on the eastern edge will wake 30 mins earlier than people on the western edge consistent with the 30 mins sun difference timing.
What are ‘morning larks’?
Morning people. Wake early, alert, and reach their peak of productivity early.
What are ‘night owls’?
Evening people, take longer to warm up, reach their productivity later.
