9.2.1 Stages Of Sleep And Brain Mechanisms 2 Flashcards
People who are awakened during OEM reported ____ 80% to 90% of the time. Later research, however, found that people also sometimes report dreams when awakened from NREM sleep.
dreams
REM dreams are more likely than NREM dreams to include striking ____ ____ and ____ ____, but not always. REM and dreams usually overlap, but they are not the same thing.
visual imagery and complicated plots
A cut through the midbrain decreases arousal by damaging the ____ ____, a structure that extends from the medulla into the forebrain.
reticular formation
Some neurons of the reticular formation have axons ascending into the brain, and some have axons descending into the spinal-cord. Those with axons descending into the spinal-cord form part of the ____ ____ of ____ ____.
medial tract of motor control
One part of the reticular formation that contributes to cortical arousal is known as the ____.
pontomesencephalon
The term ____ describes the widespread connections among neurons in this system.
reticular
These neurons in the reticular formation receive input from many ____ ____ and generate spontaneous activity of your own.
sensory systems
The axons of the neurons of the reticular formation extend into the forebrain, releasing ____ and ____, which excites cells in the hypothalamus, thalamus, and basal forebrain.
acetylcholine and glutamate
The pontomesencephalon maintains ____ during wakefulness and increases it in response to new or challenging tasks. Stimulation of the pontomesencephalon awakens a sleeping individual or increases alertness in one already awake.
arousal
The ____ ____, a small structure in the pons, is usually inactive, especially during sleep, but it emits burst of impulses in response to meaningful events, especially those that produce emotional arousal.
locus coeruleus
Axons from the locus coeruleus release ____ widely throughout the cortex, so this tiny area has a huge influence. Anything that stimulates the locus coeruleus strengthens the storage of recent memories and increases wakefulness.
norepinephrine
The hypothalamus has several axon pathways that influence arousal. One pathway releases the neurotransmitter ____, which produces excitatory effects throughout the brain. Cells releasing histamines are active during arousal and alertness.
histamine
_____ drugs, often used for allergies, counteract the transmitter histamine and produce drowsiness. Antihistamines that do not cross the blood-brain barrier avoid that side-effect.
Antihistamine
Another pathway from the hypothalamus, mainly from the lateral and posterior nuclei of the hypothalamus, releases a peptide transmitter called either ____ or ____.
orexin or hypocretin
The axons releasing orexin extend to the basal forebrain and other areas, where they stimulate neurons responsible for wakefulness. Orexin is not necessarily for waking up, but it is for ____ ____.
staying awake