Lesson 7- Sleep Flashcards
Define sleep
A reversible behavioural state of perceptual disengagement from and unresponsiveness to the environment.
What does SCN stand for?
Suprachiasmatic nucleus
Which structure is the SCN found in?
Hypothalamus
Where is the SCN positioned in relation to the optic chiasm?
directly above the optic chiasm
What is the function of the SCN?
The suprachiasmatic nucleus detects the amount light being sent to the brain for processing and then uses this information to influence the amount of melatonin being released into the bloodstream via the Pineal Gland.
Its main role is for regulating the ONSET (beginning) of sleep.
What is melatonin?
Melatonin is a hormone that is produced and secreted by the pineal gland. (a gland at the base of the brain which keeps track of the body’s natural cycles and registers external factors such as light and darkness)
It is associated with the sleep wake cycle.
What is the function of melatonin?
High levels of melatonin lead to sleepiness
Once levels of melatonin reach a critical level, a person will fall asleep.
What would be likely to occur when:
There are low levels of light in the environment (night-time)
more melatonin secreted = more sleepy
What would be likely to occur when:
There are low levels of melatonin being secreted by the pineal gland
less sleepiness/more alert/awake
What would be likely to occur when:
There are high levels of light in the environment (day-time or bright screens/blue light)
less melatonin secreted= less sleepy
What would be likely to occur when:
There are high levels of melatonin being secreted by the pineal gland
increased sleepiness/more likely to fall asleep and stay asleep
What is insomnia?
inability/difficulty to fall asleep or stay asleep
what are the psychological causes of insomnia?
a problem that causes stress, fear or anxiety
what are the physical causes of insomnia?
medical problems, pain, alcohol and drug use
