10.1 - Brainstem, arousal and sleep Flashcards
What structure is responsible for sleep regulation? how can it be divided into 2 groups, functions?
reticular formation.
Reticular nuclei can be put into 2 groups:
Ascending reticular activating system (ARAS) whcih increases levels of consciousness and secondary inhibitory area which decreases levels of consciousness
How does the ascending reticular activating system work? What has to happen to it for sleep to occur?
Filters incoming signals. Thalamocortical loop to the cortex,
For sleep, has to be inhibited by hypothalamic sleep centres
what effect does LSD have on the brain?
Inhibits ARAS and reduces filtering of incoming signals to higher centres of brain
What happens to the ARAS during slow wave sleep?
neurones from ARAS silent, reduced consciousness
What are the 4 types of brain waves seen in an EEG? When is each seen?
alpha - awake and eyes shut
beta - awake and eyes open
theta - in children and during strong emotion in adults
delta - deep sleep and serious brain conditions
What is sleep important for?
restting cns, memory, homeostasis
What 2 stages can sleep be divided into? What is the function of each?
Non-REM - made up of 4 stages. Restorative and v important for neuroendocrine functioning. Decreased cerebral blood flow, o2 usage, body temp, BP, RR, BMR. “active body, inactive brain”
REM - EEG appears as if awake. Dreams occur. “active brain, inactive body”
Symptoms and cause of narcolepsy?
cause - abnormal cholinergic neurones
symptoms - attacks of sleep during the day. sleep paralysis whilst remaining awake at night.
Symptoms and cause of insomnia?
cause can be primary (problems in sleep mechanism) or secondary (psychological or medical problem)
symptom - inability to fall asleep
Symptoms and cause of sleep apnoea? Treatment?
Interruption of breathing during sleep in order for breathing to be maintained
Cause - airway narrowing
Treatment - positive oxygen pressure during sleep
