Final Exam (Stages of Sleep and Brain Mechanisms)

Question 1

what is sleep characterized by?

Answer 1

a moderate decrease in brain activity and decreased response to stimuli

Question 2

list the four states sleep differs from

Answer 2

coma, vegetative state, minimally conscious state and brain death

Question 3

define “coma”

Answer 3

extended period of unconsciousness characterized by low brain activity that remains fairly steady. (person shows little response to stimuli)

Question 4

define “vegetative state”

Answer 4

person alternates between periods of sleep and moderate arousal but no awareness of surroundings

Question 5

how do people in a vegetative state respond to stimuli?

Answer 5

some autonomic arousal to painful stimulus, no purposeful activity/response to speech

Question 6

define “minimally conscious state”

Answer 6

one stage higher than a vegetative state marked by occasional brief periods of purposeful action and limited speech comprehension

Question 7

define “brain death”

Answer 7

no sign of brain activity and no response to any stimulus

Question 8

what allowed researchers to discover that there are various stages of sleep?

Answer 8

the electroencephalograph (EEG)

Question 9

a ________ is a combination of an EEG and ___-_______ records

Answer 9

polysomnograph, eye-movement

Question 10

which waves are present when one begins to relax?

Answer 10

alpha waves

Question 11

in stage 1 sleep, what do the eeg waves look like. what does brain activity do?

Answer 11

eeg is dominated by irregular, jagged, and low voltage waves. brain activity begins to decline

Question 12

stage 2 sleep is characterized by the presence of what two things?

Answer 12

sleep spindles and K-complex

Question 13

describe sleep spindles (and at what stage of sleep do they occur?)

Answer 13

12- to 24- Hz waves during a burst that lasts at least half a second (stage 2 sleep)

Question 14

describe K-complexes (and at what stage of sleep do they occur?)

Answer 14

sharp wave associated with temporary inhibition of neuronal firing (stage 2 sleep)

Question 15

stage 3 and 4 sleep are characterized by …

Answer 15

eeg recording of slow, large amplitude wave, slowing of heart rate and breathing rate and brain activity, highly synchronized neuronal activity

Question 16

define “paradoxical sleep”

Answer 16

deep sleep in some ways, but light sleep in other ways

Question 17

stages 3 and 4 sleep are predominantly ____ in the night. length of stage _______ as the night progresses

Answer 17

early, decreases

Question 18

REM sleep is predominantly _____ at night. length ______ as the night progresses

Answer 18

later, increases

Question 19

the reticular formation is a part of the ____ brain that extends from the ______ to the ____ brain and is responsible for _____

Answer 19

midbrain, forebrain, arousal

Question 20

the pontomesencephalon, a part of the _____ ______ in the _____, contributes to _____ ______

Answer 20

reticular formation, midbrain, cortical arousal

Question 21

the locus coeruleus is a small structure in the ____ whose axons release ___________ to arouse various ____ of the _____ and _______ wakefulness

Answer 21

pons, norepinephrine, areas, cortex, increase

Question 22

the hypothalamus contains neurons that release ______ to produce a widespread ______ effects though out the brain.

Answer 22

histamine, excitatory

Question 23

what is orexin?

Answer 23

a peptide neurotranmitter

Question 24

what structure releases orexin?

Answer 24

the lateral and posterior nuclei of the hypothalamus

Question 25

what is orexin needed for?

Answer 25

to stay wake rather than wake up

Question 26

functions of the inhibitory neurotransmitter ____ are also important for what two things?

Answer 26

GABA, decreasing the temperature and metabolic rate and decreasing the stimulation of neurons