PSYC201 Test 2, Week 8

Question 1

Why do certain proteins involved in biological rhythms have short lifespans?

Answer 1

They only stay elevated when continuously stimulated; in the evening, activation decreases and their concentration drops.

Question 2

What is the role of the Suprachiasmatic Nucleus (SCN)?

Answer 2

It is the brain’s master clock, located in the hypothalamus, and maintains an inherent 24-hour rhythm.

Question 3

What is the function of melanopsin-containing ganglion cells?

Answer 3

They detect light (especially blue light), send signals to the SCN, and help regulate circadian rhythms.

Question 4

What happens to Per and Tim protein levels throughout the day?

Answer 4

Low in the morning, increase during the day, peak in the evening, then inhibit the clock and decrease again.

Question 5

What is an endogenous circannual rhythm?

Answer 5

A yearly biological rhythm that persists even without environmental cues.

Question 6

What are circadian rhythms?

Answer 6

Biological processes that follow a roughly 24-hour cycle, such as sleep-wake patterns and body temperature.

Question 7

What is a zeitgeber?

Answer 7

An external cue, like light, that helps reset the biological clock.

Question 8

How does light affect circadian rhythms?

Answer 8

Light, especially blue light, is the main zeitgeber that synchronizes the internal clock with the environment.

Question 9

What tools are used to measure sleep stages?

Answer 9

EEG (brain activity) and EOG (eye movement).

Question 10

What characterizes Stage 1 sleep?

Answer 10

Decreased EEG activity and reduced eye movement.

Question 11

What is unique about Stage 2 sleep?

Answer 11

Presence of sleep spindles and K-complexes, important for memory consolidation.

Question 12

What is slow-wave sleep?

Answer 12

Deep sleep with regular EEG patterns and some eye movement.

Question 13

What is REM sleep?

Answer 13

A stage with rapid eye movements and EEG patterns similar to wakefulness; associated with vivid dreams.

Question 14

How does sleep change in older adults?

Answer 14

More fragmented sleep, less slow-wave sleep, more Stage 1 sleep, but REM sleep remains relatively stable.

Question 15

What does the Pineal Gland produce and when is it active?

Answer 15

Produces melatonin; active at night to help you stay asleep.

Question 16

How does melatonin affect diurnal and nocturnal animals?

Answer 16

In diurnal animals, melatonin promotes sleep; in nocturnal animals, it promotes wakefulness.

Question 17

What is one of the strongest inhibitors for the production of melatonin?

Answer 17

Caffeine.

Question 18

How can excessive coffee consumption affect the pineal gland?

Answer 18

Excessive coffee may shrink the pineal gland.

Question 19

What is the Reticular Formation and its function?

Answer 19

Regulates internal processes; connects to almost all brain parts; receives input from the thalamus; has ascending and descending pathways.

Question 20

What is the function of the Pontomesencephalon?

Answer 20

Receives sensory input and aligns with circadian rhythm. Uses acetylcholine and glutamate to promote wakefulness; GABA promotes sleep.

Question 21

What is the Locus Coeruleus and its function?

Answer 21

Contains the highest concentration of noradrenaline; boosts alertness and signal-to-noise ratio.

Question 22

What is the function of the Hypothalamus?

Answer 22

Regulates thirst, hunger, and temperature. Histamine and orexin increase alertness and wakefulness.

Question 23

What is Propofol and its function?

Answer 23

GABA agonist; induces general anesthesia.

Question 24

What is Ketamine and its function?

Answer 24

Glutamate antagonist; induces general anesthesia.

Question 25

How does increased GABA activity affect sleep?

Answer 25

Increases during sleep, reducing thalamic activity and sensory input to the cortex. Weakens brain connectivity, allowing localized sleep.

Question 26

What is sleepwalking and how common is it?

Answer 26

More common in children (5%) than adults (1.6%). Motor cortex is awake while other areas are asleep.

Question 27

What is lucid dreaming and how common is it?

Answer 27

Awareness of dreaming; occurs in ~23% of people. Linked to frontal and temporal brain activity.

Question 28

What are the symptoms of insomnia and hypersomnia?

Answer 28

Insomnia: Too little sleep; linked to depression, irritability, and psychiatric issues. Hypersomnia: Excessive sleep; also linked to depression and similar issues.

Question 29

What is sleep apnea and its effects?

Answer 29

Breathing difficulty during sleep; causes frequent awakenings, daytime sleepiness, and increased health risks.

Question 30

What is narcolepsy and its triggers?

Answer 30

Sudden sleep episodes, cataplexy, and sleep paralysis. Triggered by emotion; caused by reduced orexin.

Question 31

What are the functions of sleep?

Answer 31

Conserves energy, maintains cells, strengthens synapses, and consolidates memory

Question 32

What is REM sleep and its importance?

Answer 32

Increases with more sleep. Starts in the pons → geniculate → occipital cortex (PGO). Important for memory and eye health.

Question 33

What is the Activation-Synthesis Hypothesis?

Answer 33

Bottom-up; brain makes sense of random activity.

Question 34

What is the Neurocognitive Hypothesis?

Answer 34

Top-down; dreams reflect ongoing mental processing of daily events.

Question 35

What is the autonomic nervous system (ANS)?

Answer 35

A motor system that links the brain to internal organs and regulates involuntary functions.

Question 36

What are the two main divisions of the nervous system?

Answer 36

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Question 37

What are the two branches of the PNS?

Answer 37

Autonomic Nervous System (ANS) and Somatic Nervous System

Question 38

What are the two main branches of the ANS?

Answer 38

Sympathetic and Parasympathetic Nervous Systems

Question 39

What type of fibers dominate the ANS?

Answer 39

Motor fibers from the brain and spinal cord to target organs

Question 40

What is the enteric nervous system?

Answer 40

A part of the ANS intrinsic to the GI system, often called the "second brain"

Question 41

What neurotransmitter is used by most preganglionic fibers in both sympathetic and parasympathetic systems?

Answer 41

Acetylcholine

Question 42

Where are sympathetic preganglionic neurons located?

Answer 42

In the spinal cord

Question 43

What neurotransmitter do sympathetic postganglionic neurons typically use?

Answer 43

Noradrenaline

Question 44

What are some effects of sympathetic activation?

Answer 44

Pupil dilation, bronchial dilation, increased heart rate, bladder relaxation

Question 45

Where are parasympathetic preganglionic neurons located?

Answer 45

In the hindbrain and sacral spinal cord

Question 46

What neurotransmitter do parasympathetic postganglionic neurons use?

Answer 46

Acetylcholine

Question 47

What are some effects of parasympathetic activation?

Answer 47

Pupil contraction, bronchial contraction, decreased heart rate, bladder contraction

Question 48

What is HRV?

Answer 48

The variation in time between heartbeats

Question 49

What does high HRV indicate?

Answer 49

Greater flexibility in brain and heart function, better attentional control, and risk aversion

Question 50

What does low HRV indicate?

Answer 50

Lower cognitive flexibility and is associated with many mental health conditions

Question 51

Which mental health conditions are associated with low HRV?

Answer 51

Schizophrenia, MDD, Bipolar Disorder, ASD, ADHD, Addiction, GAD, PTSD

Question 52

What brain region is linked to HRV and flexible thinking?

Answer 52

Prefrontal cortex

Question 53

Which organs are only influenced by the sympathetic system?

Answer 53

Sweat glands, liver, adrenal glands