BMB 3 - Disorders of Eating & Sleep

Question 1

Which is the most dangerous (yet rare) eating disorder?

Answer 1

Anorexia nervosa

Question 2

What disorder is characterized by a deliberate reduction in body mass as measured by BMI?

(Also, it may be induced by food restriction or binge-eating/purging.)

Answer 2

Anorexia nervosa

Question 3

Anorexia nervosa is characterized by the refusal to maintain a body weight at or above _____% of expected weight.

Answer 3

Anorexia nervosa is characterized by the refusal to maintain a body weight at or above 85 % of expected weight.

Question 4

Name some psychological disturbances that are features of anorexia nervosa.

Answer 4

Fear of gaining weight;

body image disturbance;

lack of awareness of the seriousness of low body weight

Question 5

True/False.

The low nutrient scenario associated with anorexia nervosa can damage white matter tracks of the brain, decrease bone stability, and induce electrolyte abnormalities

Answer 5

True.

Question 6

What is the basis of treatment for anorexia nervosa?

Answer 6

Psychotherapy and nutritional support

Question 7

Although not totally effective, what medication is used as an adjuvant for treating anorexia nervosa?

Answer 7

SSRIs

Question 8

One should be wary of what problem while treating anorexia nervosa?

Answer 8

Refeeding syndrome

(When one ingests too much food or liquid nutritional supplement during the initial four to seven days following a malnutrition event, the production of glycogen, fat and protein in cells may cause low concentrations of serum potassium, magnesium and phosphorus.)

Question 9

Refeeding syndrome is characterized by low serum concentrations of what?

Answer 9

Potassium, magnesium and phosphorus

Question 10

A patient who is not underweight experiences recurrent episodes of binge eating followed by compulsive behavior to counteract weight gain.

Is this anorexia nervosa?

Answer 10

No

(Bullemia nervosa)

Question 11

Give some examples of weight loss strategies sometimes utilized in bullemia nervosa.

Answer 11

Vomiting,

laxative abuse,

starvation,

exercise

Question 12

Bullemia nervosa is characterized by binge episodes and compulsive weight loss in episodes that occur ≥ __x every week for ≥ _________.

Answer 12

Bullemia nervosa is characterized by binge episodes and compulsive weight loss in episodes that occur ≥ 1 x every week for ≥ 3 months.

Question 13

Patients with bullemia nervosa is often characterized by puffiness (fluid retention activated), dental caries, esophageal erosion, parotitis (‘_________ cheeks’), and callouses on knuckles (_________’s sign).

Answer 13

Patients with bullemia nervosa is often characterized by puffiness (fluid retention activated), dental caries, esophageal erosion, parotitis (‘chipmunk cheeks’), and callouses on knuckles (Russell’s sign).

Question 14

Name some of the physical characteristics often seen in patients with bullemia nervosa.

Answer 14

Dental carries,

parotitis,

esophageal lacerations,

calluses on knuckles.

Question 15

What is the BMI/weight likely to be in a patient with bullemia nervosa?

Answer 15

Normal or slightly elevated

Question 16

What is the basis of treatment for bullemia nervosa?

Answer 16

Psychotherapy and nutritional support

Question 17

Although not totally effective, what medications can be used as adjuvants for treating bullemia nervosa?

Answer 17

SSRIs

Topiramate

Question 18

A patient who is not underweight experiences recurrent episodes of binge eating and a lack of perceived control over food intake (but no purging activities).

Is this bullemia nervosa?

Answer 18

No

(Binge eating disorder)

Question 19

Binge eating disorder is characterized by binge episodes and compulsive weight loss in episodes that occur ≥ __x every week for ≥ _________.

Answer 19

Binge eating disorder is characterized by binge episodes and compulsive weight loss in episodes that occur ≥ 1 x every week for ≥ 3 months.

Question 20

Treatment for binge eating disorder includes psychotherapy (CBT) with adjuvant use of what medication(s)?

Answer 20

SSRIs,

lisdexamfetamine,

or topiramate

Question 21

What disorder is characterized by one with an appetite for and ingestion of nonnutritive substances?

Answer 21

Pica

Question 22

Pica is most commonly seen in what populations?

Answer 22

Children or pregnant women

(eating sticks, rocks, sand, or something else that is not normal)

Question 23

True/False.

Nearly all patients with eating disorders are very aware of their disorder and actively seek medical intervention.

Answer 23

False.

Patients with eating disorders often hide or protect their disorder.

Question 24

Which brain nuclei are largely the main ‘internal clock’ maintaining our circadian rhythyms?

Answer 24

The suprachiasmatic nuclei

Question 25

The most important cue for the circadian clock Is the \_\_\_\_\_\_\_\_\_\_\_\_.

Answer 25

The most important cue for the circadian clock Is the **_environment_**.

Question 26

What does the pineal gland produce and when?

Answer 26

Melatonin; during darkness

Question 27

**True/False**. Darkness is not necessary for the melatonin signal, but sleep is.

Answer 27

**False**. ***Sleep*** is not necessary for the melatonin signal, but ***darkness*** is.

Question 28

Which organ is the main source of melatonin production?

Answer 28

The pineal gland

Question 29

_When influenced_ by external cues, an active, self-sustained oscillator (e.g. the suprachiasmatic nuclei) is known as a(n) ______________ circuit. _When not influenced_ by external cues, an active, self-sustained oscillator (e.g. the suprachiasmatic nuclei) is known as a(n) ______________ circuit.

Answer 29

_When influenced_ by external cues, an active, self-sustained oscillator (e.g. the suprachiasmatic nuclei) is known as an **_entrained (synchronized)_** **_rhythm_** circuit. _When not influenced_ by external cues, an active, self-sustained oscillator (e.g. the suprachiasmatic nuclei) is known as a **_free-running rhythm_** circuit.

Question 30

The peak of a circadian rhythm is known as the what?

Answer 30

The **acrophase**

Question 31

The time between circadian rhythm peaks (or troughs) is known as the what?

Answer 31

A **period** (**tau**)

Question 32

A particular point in a circadian rhythm is known as the what?

Answer 32

A **phase**

Question 33

The distance between a peak and a trough within a graphed circadian rhythm is known as the what?

Answer 33

The **amplitude**

Question 34

What term refers to a circadian rhythm peak occuring earlier than expected?

Answer 34

Phase advance

Question 35

What term refers to a circadian rhythm peak occuring later than expected?

Answer 35

Phase delay

Question 36

Phase shifts (i.e. advance or delay) in circadian rhythms are typically seen when?

Answer 36

In **sleep disorders**

Question 37

Where do the suprachiasmatic nuclei receive information about light/dark cycles?

Answer 37

The optic nerves

Question 38

Our circadian rhythms are tuned to react to what wavelengths?

Answer 38

460 - 480 nm | (**blue** light)

Question 39

**True/False**. Red light has little-to-no effect on our circadian rhythms.

Answer 39

True.

Question 40

A small population of retinal ganglion cells (~\_\_%) are photoreceptors, aka _____________________________ (IPRGCs).

Answer 40

A small population of retinal ganglion cells (~ **_1_** %) are photoreceptors, aka **_intrinsically photoreceptive retinal ganglion cells_** (IPRGCs).

Question 41

What do intrinsically photoreceptive retinal ganglion cells (IPRGCs) contain instead of rhodopsin?

Answer 41

**Melanopsin** | (a blue light pigment)

Question 42

What are the two major drivers of the sleep/wake cycle?

Answer 42

**Process S** (homeostatic sleep drive) **Process C** (circadian drive for arousal)

Question 43

Describe the basics of process S (homeostatic sleep drive) and process C (circadian drive for arousal) of the sleep/wake cycle.

Answer 43

_Process S_ (homeostatic sleep drive) - **homeostatic urges to rest that build up as the day goes on and cause sleepiness** _Process C_ (circadian drive for arousal) - **stimulation of the suprachiasmatic nuclei by blue light increases arousal**

Question 44

What bedtime interplay between processes C and S is known as the _sleep gate_ and is the time when one transitions from consciousness to sleep?

Answer 44

At bedtime, your homeostatic sleep drive (process S) is at its peak and your circadian drive for arousal drops off as light input decreases (process C)

Question 45

**True/False**. Misalignment between process S and process C can cause sleep disturbance.

Answer 45

True.

Question 46

What is the technical term for preferring morning hours (being an early riser or 'lark' chronotype)?

Answer 46

Morning diurnal preference

Question 47

What is the technical term for preferring evening hours (being a late riser or 'owl' chronotype)?

Answer 47

Evening diurnal preference

Question 48

**True/False**. One week of camping in natural light resets circadian clockworks, making 'lark' and 'owl' chronotypes more disparate.

Answer 48

**False**. One week of camping in natural light resets circadian clockworks, making 'lark' and 'owl' chronotypes more ***alike***.

Question 49

Identify the described sleep disorder type: ## Footnote *stable delay of the major sleep period by habitual onset and wake-up times several hours later relative to conventional and desired times.*

Answer 49

**Delayed sleep phase** type

Question 50

Identify the described sleep disorder type: ## Footnote *stable advance of the major sleep period by habitual onset and wake-up times several hours earlier relative to conventional and desired times.*

Answer 50

**Advanced sleep phase** type

Question 51

Identify the described sleep disorder type: ## Footnote *steady drift of the major sleep period by 1-2 hours each day.*

Answer 51

**Non-entrained (aka free-running or “Non-24”)** type

Question 52

Identify the described sleep disorder type: ## Footnote *Absence of a clear circadian rhythm of sleep/wake​.*

Answer 52

**Irregular sleep-wake** type

Question 53

Identify the described sleep disorder type: ## Footnote *temporary misalignment between the circadian clock and external time caused by rapid travel across time zones.*

Answer 53

**Jetlag** type

Question 54

Identify the described sleep disorder type: ## Footnote *circadian misalignment that occurs when shift workers attempt to sleep at unusual circadian times because they have exposure to light at night.*

Answer 54

**Shift work sleep** type

Question 55

_Some sleep disorders can be treated with light therapy_: A person with with a advanced sleep phase can be exposed to bright light \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. A person with with a delayed sleep phase can be exposed to bright light \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 55

_Some sleep disorders can be treated with light therapy_: A person with with a advanced sleep phase can be exposed to bright light **_before bedtime_**. A person with with a delayed sleep phase can be exposed to bright light **_when they wake up_**.

Question 56

Wakefulness, as it relates to circadian synchrony, corresponds with what factors? feeding and energy storage, and it relates to __________ as it corresponds with fasting and energy utilization.

Answer 56

Feeding and energy storage

Question 57

Sleep, as it relates to circadian synchrony, corresponds with what factors?

Answer 57

Fasting and energy utilization

Question 58

**True/False**. _Circadian asynchrony_ (e.g. due to shift work) can lead to _altered metabolic phenotypes_, due to sleep and circadian disruption.

Answer 58

True.

Question 59

What issues of sleep length and diet can disrupt the circadian clock?

Answer 59

Sleep deprivation, prolonged wakefulness, and a high-fat diet

Question 60

What organ inhibits the spontaneous production of melatonin by the pineal gland? Via what substance?

Answer 60

The suprachiasmatic nuclei; norepinephrine *(So, blue light hits your eye, the optic nerves stimulate the SCN, the SCN inhibits the pineal gland.)*

Question 61

What is the melatonin burst like during the Summer months (short nights)?

Answer 61

**Shorter** melatonin burst

Question 62

What is the melatonin burst like during the Winter months (long nights)?

Answer 62

**Longer** melatonin bursts, **but same amplitude**

Question 63

Melatonin is derived from \_\_\_\_\_\_\_\_\_\_.

Answer 63

Melatonin is derived from **_tryptophan_**.

Question 64

Name the three intermediates between tryptophan and melatonin.

Answer 64

Tryptophan → **5-hydroxytryptophan** → **Serotonin** → **N-acetylserotonin** → Melatonin

Question 65

What enzyme converts N-acetylserotonin to melatonin? ## Footnote *(NOTE: this is the rate-limiting step of melatonin production.)*

Answer 65

N-acetyltransferase enzyme

Question 66

What is the rate-limiting step of melatonin production?

Answer 66

N-acetylserotonin to melatonin

Question 67

What substance gets us through the sleep gate and into sleep?

Answer 67

Melatonin

Question 68

**True/False**. Melatonin is low in early childhood and increases as we age (causing sleep disturbances in the elderly).

Answer 68

**False**. Melatonin is ***high*** in early childhood and ***decreases*** as we age.

Question 69

The G-lymphatic system removes metabolic waste (e.g. beta-amyloid) from CNS tissues during what time?

Answer 69

Sleep

Question 70

What cell type controls G-lymphatic system removal of metabolic waste (e.g. beta-amyloid) from CNS tissues?

Answer 70

Astrocytes

Question 71

What is the most current hypothesis for the reason that shift workers have a higher risk of developing breast and prostate cancer?

Answer 71

**Melatonin has anti-cancer properties** (via direct inhibition of the growth, progression, and metastasis of cancer)