FS21
Fichier Détails
| Cartes-fiches | 16 |
|---|---|
| Langue | Deutsch |
| Catégorie | Biologie |
| Niveau | Université |
| Crée / Actualisé | 29.05.2021 / 02.07.2021 |
| Lien de web |
https://card2brain.ch/box/20210529_physiology_of_eating_l1011
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Why & How can stress inhibit or promote eating?
(2)
(3)
(1)
1. acute stress: inhibits eating: CRF & urocortin act on AgRP/POMC Neurons in ARC
2. chronic stress: increases wanting + consumption of palatable foods via dopaminergic system
-> Depends on many factors: Nature of stress (physiologic, psychogenic), intensity/duration, prior experiences with food, restraint eating score
-> independent of whether more/less food is consumed when stressed, there is always a shift toward more comfort foods
Basic Mechanisms of Effects of Glucocorticoids on Eating (3)
1. increase of wanting/eating palatable foods -> increase in insulin resistance, more FFA release and uptake -> more MESENTERIC AT
2. increased fructose consumption -> activation of 11beta-HSD-1 -> stimulates release of more glucocorticoids
3. increased gluconeogenesis, insulin (resistance), LPL (enzyme that directs energy to various tissues) -> more MESENTERIC AT
How does (lack of) sleep contribute to obesity?
(2)
(3)
(1)
(1)
1.
a. endocrine changes (increased ghrelin, decreased leptin) -> increased hunger
b. Hedonic factors -> increased time/opportunity to eat, increased food reward
2.
a. decreased thermogenesis
b. increased fatigue
c. decreased physical activity
-> increased energy intake + decreased energy expenditure
(+ another factor is gut dysbiosis -> disrupted intestinal barrier + increased LPS translocation)
Effects of estradiol on eating (3)
1. Inhibiting effect on food intake -> major effect is enhancement of CCK satiation by acting in hindbrain
2. estradiol receptors are all over brain -> also in many areas involved in eating regulation/energy homeostasis
3. Estradiol can act in all these areas! (and thus has an effect on food intake)
Premenstrual disorders (3)
1. high fluctuations of estrogen/progesterone
2. depends on individual differences -> genetics, stress, history of mood disorders
3. women show disturbed eating! -> changes coincide with changes in serotonin activity (depression..)
Estradiol & Menopause (4)
1. menopause: dramatic drop in estrogen levels + estrogen dominance (over progesterone)
2. leads to disrupted estrogen-related systems (e.g. thermoregulation, sleep, circadian rhythm etc.)
3. thus MAINLY neurological symptoms -> hot flushes, insommnia, mood changes, depression, eating, impaired cognitive function
4. Estradiol receptors: ESR1, ESR2, GPER
Why do women gain weight during menopause?
estrogen & FSH levels decrease, which leads to a decrease in muscle mass & strength, energy expenditure and adipose cell metabolism -> increased body weight
Bidirectional interaction between obesity & depression (4)
1. factors that trigger the cycles: genetics, stress, poor diet
-> Neuroendocrine effects (HPA-axis, leptin, insulin dysregulation)
-> Gut Microbiota (Dysbiosis)
-> Adipose tissue (increased lipogenesis, pro-inflammatory cytokines)
2. All of this leads to neuroinflammation (also via IDO, which is a key enzyme involved in the synthesis of monoamines (serotonine, dopamine)
3. Altered brain activity for mood&food
4. Depression <-> Obesity
Effects of estradiol on serotonin
(4)
1. simulates biosynthesis of serotonin
2. inhibits serotonin degradation
3. blocks serotonin uptake
4. potentiates serotonin receptor activation
Name 4 types of ED and what they ALL have in common (3)
1. anorexia nervosa
2. bulimia nervosa
3. binge eating disorder
4. orthorexia nervosa
1. violations lead to self-punishement
2. guilt/self-loathing
3. risk for social isolation
General causes for ED
(7)
1. no direct causes are known
2. genetics & familial influences
3. obesessive- compulsive personality type (perfectionism, poor coping with stress, rigidity)
4. dysfunction of monoaminergic neurotransmission
5. sociocultural influences equating beauty with an overly thin physique
6. almost always begins with dieting -> positive feedback -> obtain reward for not eating
7. some imbalance in the dopaminergic (reward) & serotonic system is involved
Psychological (5) and physical (7) consequences of ED
1. depression
2. obsession with food
3. low sociability
4. poor attention & concentration (mainly AN)
5. loss of libido/lack of interest in sex (mainly AN)
1. low leptin (mainly AN)
2. low estrogn, FSH, LH (mainly AN)
3. Amenorrhoea
4. low BMD (mainly AN)
5. impaired gastric system
6. impaired immune system
7. impaired dental status (AN and BN, but more BN)
viscious cycle of AN
10
Dieting -> increased attention to nutrient caloric content -> increased attention to BW/shape, size -> strict rules (what, when, how much eating) -> exercise -> routine of eating/exercise becomes rigid -> obession with food -> practice deception to hide habits, wear loose clothes -> social avoidance -> psycholocial signs of starvation
viscious cycle of Bulimia (9)
Diet -> cravings -> break rule/eat -> guilt -> binge -> guilt/shame -> compensatory behavior (purge/vomit/laxatives) -> guilt/depression -> diet
Treatment Anorexia Nervosa (7)
1. dont want to be treated
2. nutritional rehabilitation + restoring weight is essential
3. family therapy
4. highly controlled & structural environment
5. cognitive-behavior therapy most effective
6. the sooner start, the better, intenste treatment not always better
7. outcome better for adolescents
Treatment Bulimia Nervosa
(3)
1. want to be treated
2. cognitive-behavioral therapy -> short term, focus on restructuring maladaptive thoughts&m behaviors
3. Drug Treatment -> Antidepressants reduce binge/purge behavior, serotonin reuptake inhibitors have the least side effects
