Module 9.2 Flashcards
What are the defining characteristics for coma?
extended period of unconsciousness caused by head trauma, stroke, or disease; low level of brain activity; little to no response to stimuli
What are the defining characteristics for vegetative state?
alternating between periods of sleep and moderate arousal; breathing is more regular; a painful stimulus produces at least the responses of increased heart rate, breathing, and sweating; no speaking, response to speech, or any purposeful activity
What is an EEG?
it records the degree of synchrony of neuronal activity; enables researchers to compare brain activity at different times during sleep
What is the behavioral correlate of alpha waves?
relaxation
What are the defining characteristics of a minimally conscious state?
occasional brief periods of purposeful actions and a limited amount of speech comprehension
What are the defining characteristics of brain death?
no sign of brain activity or response to stimuli
Describe the EEG in stage 1 sleep.
irregular, jagged, low-voltage waves
What are the EEG characteristics of Stage 2 sleep?
k-complex and sleep spindles
Which stages of sleep are classed as slow-wave sleep (SWS)?
stages 3 and 4
Why is REM sleep called paradoxical?
because it is deep sleep in some ways and light sleep in others
What is a polysomnograph?
a combination of EEG and eye-movement records
What is the typical duration of the sleep cycle?
about 90 minutes
During which part of the night is REM predominant?
towards the morning
During which parts of the night are stages 3 & 4 predominant?
earlier in the night
How good is the correlation between REM sleep and dreaming?
they usually overlap
What is the effect of a cut through the midbrain on sleep and waking cycles?
Was the result due simply to loss of sensory input or damage to a particular brains structure?
If a cut through the midbrain is made, sleep periods become longer and wake periods become more brief. Damage to a particular brain structure, reticular formation.
What is the pontomesencephalon’s relation to the reticular formation?
it is part of the reticular formation
Describe the input, output, and interconnections of the pontomesencephalon.
It receives input from many sensory systems and generates spontaneous activity. Their axons extend into the forebrain and release acetylcholine and glutamate, which excites cells in the hypothalamus, thalamus, and basal forebrain.
Give the location, neurotransmitter, and a major function of the locus coeruleus.
The locus coeruleus is located in the pons. It releases norepinehrine and it strengthens the storage of recent memories.
What is the neurotransmitter from the hypothalmus that stimulates arousal?
histamine