Week 3 - Lec 16 pt.2 Consciousness and Sleep

Question 1

What are the 2 stages of sleep discussed in class?

Answer 1

1. Deep Sleep
2. Rapid Eye Movement (REM)

Question 2

What is the activity level of the brain and body during each of these sleep stages (relatively)? There are 2 stages of sleep.

Answer 2

Deep Sleep (NREM): In the brain the cerebral cortext activity is minimal AND the heart rate, blood pressure, respiratory rate, and energy use is decline up to 30%

• This is where no dreaming occurs and often hard to wake up

Rapid Eye Movement (REM): Active dreaming occurs and resumes daytime blood pressure, heart rate, and temperature

Question 3

Why is the body limp during REM although the brain is very active?

Answer 3

the body experiences muscle atonia which is the state of near complete paralysis. This mechanism can protectus us from acting out dreams

Question 4

What is REM sleep?

Answer 4

Wakeful-like brain and metabolic activity, but skeletal muscles are actively inhibited

Question 5

During which stage is your metabolic rate lower?

Answer 5

Deep Sleep

Question 6

What is the reticular activating system (RAS) and

Answer 6

Is a network of neurons in the brainstem that plays an important role in regulaing sleep-wake cycles, arousal, and conscious perception

Question 7

What role does the RAS play in being awake or being asleep?

Answer 7

Awake: sends sensory information to parts of the cerebral cortex, promoting wakefulness and attention

Asleep: During sleep the RAS activity decreases contributing to the maintenance of sleep

Question 8

During sleep, what happens to the RAS?

Answer 8

RAS is inhibited

*Inhibited means unable to act in a relaxed and natural way

Question 8

Where are the RAS nuclei?

Answer 8

Primarily within the hypothalamus and brainstem

Question 9

What parts of the brain are involved in the RAS?

Answer 9

the brain stem that extends to the hypothalamus, thalamus, and basal forebrain

Question 10

What is the function of the thalamus?

Answer 10

Body information relay station.

RAS projects sensory information the the thalamus then is relayed to other parts of the cerebral cortex

*Helps regulate alertness and consciousness

Question 11

What is the function of hypothalamus?

Answer 11

helps mamange your body temperature, hunger and thirst, mood, sex drive

Question 12

Are you always
consciously aware of every stimulus in the environment or are some stimuli filtered out?

Answer 12

Not always, people are only consciously awake of a small fraction of the sensory information they receive and filter out the rest sometimes called selective perception theory