McNamara, Ch. 2 Flashcards
What is the Suprachiasmatic nucleus?
the brain region that appears to act as the master circadian clack in humans.
Where is the SCN located?
above the optic chiasm and at the bottom of the hypothalamus.
The SCN receives light information from ganglion cells in the retina that contain this unique photosensitive pigment.
melanopsin
The core cells of the SCN entrain firing patterns with the light and dark cycle. What do the shell cells do?
aid in the appropriate release of melatonin
What is the pathway by which the brain releases and uses melatonin?
produced and synthesized by the pineal gland
Shell cells from SCN project to the paraventricular nucleus in the hypothalamus.
Connections from that nucleus to the SCN help regulate melatonin release
What process begins once humans fall asleep?
the ultradian cycle
What is the name of the graph we use to portray the changes in EEG and arousal states over the NREM-REM sleep times across a single night of sleep?
the hypnogram
What is on the horizontal axis of a hypnogram?
time
What is on the vertical axis of a hypnogram?
sleep state
What do GABA neurons do?
the project to all the brain stem’s wake-promoting neurons and turns them off so sleep may begin.
What is caffeine’s effect on adenosine?
it blocks the cumulation of adenosine and thus, sleepiness.
Energy is stored as glycogen in the glial cells of the brain. What happens when sleep deprivation occurs in these cells?
They release their glycogen stores for energy, which activates the release of adenosine.
What are the two components of the two process sleep regulation model?
Process S (sleep) Process C (circadian rhythm)
What does the two process model not address?
the homeostatic aspects of REM
what is a multi-oscillator model?
two or more oscillators create the cycles of each variable being monitored.
Describe the flip-flop model.
states that when one mechanism is switched to on (Process S) the other is turned off (Process C.)
Sleep active neurons in the ventrolateral preoptic nucleus (VLPO) oppose what?
wake active neurons within the hypothalamus and brainstem.
what is a zeitgeber?
a “timekeeper.” a signal that entrains bodily rhythms to regularly occurring social events.
DO circadian cycles tend to be less variable in morning or evening people?
morning people
Describe Delayed Sleep Phase Disorder (DSPD).
sleep schedules are advanced two hours later than conventional sleep times.
Describe Advanced Sleep Phase Disorder (ASPD).
characterized by falling asleep faster than social convention dictates.
How can you treat DSPD?
exposure to bright lights in the morning and reduce light exposure in the evening
Melatonin delivered six hours before bedtime to reset clock.
How can you treat ASPD?
light exposure in the evening to delay sleep onset.
Name the three other disorders addressed in Ch. 2.
jet-lag disorder
Seasonal Affective Disorder (SAD)
bipolar I