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Flashcards in 111 - Obesity Deck (48):
1

What type of meal produces the greatest release of serotonin within the hypothalamus?

A carbohydrate rich meal

2

What is the gene that produces leptin

The Ob gene

2

How come Sibutramine has been withdrawn from clinical use?

It has been linked to cardiovascular side-effects

2

What can cause the basal metabolic rate to slow down?

  • Hypothryoidism
  • Diet or starvation
  • Sustained illness
  • Hypothermia

3

What are the differences of NAD+ and NADP+ function?

  • NAD+ carries electrons during catabolism to Oxygen during respiration
  • NADP+ supplies electrons for biosynthetic reduction in anabolic processes

4

What is Sibutramine a derivative of?

The amphetamine precursor β-phenylethylamine

5

Where does the Vagus nerve project to regarding information about stomach distention and CCK release?

The nucleus of the solitary tract, which then feeds into the hypothalamus

5

What class of drug is Sibutramine (Reductil)?

A serotonin and noradrenaline reuptake inhibitor (SNRI) - Antidepressant

6

What is insulin's effect on the hypothalamus?

It stimulates it to release anorectic peptides such as α-MSH

6

What are some of the serious complications of obesity?

  • Pulmonary disease; obstructive sleep apnoea
  • Idiopathic intracranial hypertension
  • Stroke
  • Coronary heart disease
  • Non-alcoholic fatty liver disease
  • Cancers

7

Which layer of the embryo does the GIT develop from?

Endodermal layer

9

What are the 3 main nuclei of the hypothalamus involved in appetite regulation?

  1. Lateral hypothalamic area
  2. Venteromedial hypothalamic area
  3. Arcuate nucleus

10

What are the proteins that are expressed as part of the orexigenic pathway?

  • Neuropeptide Y (NPY)
  • Agouti-pathway related protein (AgRP)

10

How much weight is gained with every 3500Kcal excess ingested?

Approximately 1lb of fat

11

Where is dopamine produced?

The ventral tegmental area and substaintia nigra

11

What 2 naturally occurring endocannabinoids are mimicked by Delta9 THC (cannabis)?

  1. Anandamide
  2. 2-arachidonyl glycerol

12

What are the basic behaviours that the hypothalamus controls?

  • Hunger; glucostat cells, leptin receptors
  • Thirst; osmoreceptors in OVLT 
  • Thermoregulation

12

What are the effects of endocannabinoid activation on the mesolimbic system (Hedonic)?

It increases dopaminergic signalling in the nucleus accumbens

It produces synergism with the opioid system

This also produces the feeling of hunger --> "Munchies"

13

Which drug, that has now been withdrawn, blocked the CB1 receptor?

Rimonabant (Accomplia)

13

Which tissues rely solely on glucose for metabolism?

  • RBCs
  • Lymphocytes
  • Brain
  • Muscle (severe exercise)

14

What is Orlistat a derivative of?

Lipstatin; produced by Streptomyces toxyricini

15

Where in the brain does Ghrelin act?

It acts on the arcuate nucleus of the hypothalamus

16

What tissues use fatty acids as a source of energy?

  • Liver
  • Kidney cortex
  • Cardiac muscle
  • Skeletal muscle (except severe exercise)

17

What conditions are grouped together in the term "Metabolic Syndrome"?

  • Obesity
  • Type 2 diabetes
  • Hypertriglyceridaemia
  • Microalbuminuria
  • Hypertension

19

Where do both the orexigenic and anorexigenic pathways feed into in the brain?

The lateral hypothalamus

20

What 2C molecule is used for ketogenesis?

Acetyl CoA

20

What is the first line treatment for obesity?

Lifestyle modification; diet and exercise

21

Which tissues use ketone bodies as a source of energy?

  • Cardiac muscle
  • Kidney cortex
  • Brain in starvation
  • Skeletal muscle

22

What substances in the brain suppress food intake?

  • α-MSH
  • Corticotropin-releasing hormone/ urocortin
  • GLP-1
  • Cocaine and amphetamine regulated transcript (CART)
  • NA
  • 5-HT

23

What enzyme does leptin inhibit in the hypothalamus?

AMP kinase

25

Where is leptin secreted from?

Adipose cells

27

Which nucleus in the hypothalamus senses a decrease in blood glucose and drives the feeling of hunger?

Lateral hypothalamic area

28

Over what BMI has increased cardiovascular disease mortality and an increased of type 2 diabetes been linked to?

A BMI over 24/25

29

What are the central neuropeptides and neurotransmitter that stimulate food intake?

  • Neuropeptide Y
  • AgRP
  • Galanin
  • Orexin-A
  • Dynorphin

30

Where is Ghrelin synthesised?

It is produced from cells in the fundus of the stomach

32

Which part of the arcuate nucleus is the appetite suppression (anorexigenic pathway) located in?

The dosrolateral part of the arcuate nucleus

34

How is α-melanocyte-stimulating hormone (α-MSH) produced in the arcuate nucleus?

It is formed by the cleavage of POMC by the action of PC1

35

How does Orlistat help with weight loss?

It inhibits gastric, pancreatic and carboxylester lipases therefore inhibiting the digestion and absorption of fat through mixed micelles

37

What is the receptor that α-MSH binds to?

Mc4 receptor

39

What are the symptoms of Prader-Willi Syndrome?

  • Chronic feeling of hunger leading to obesity
  • Low muscle tone
  • Short stature
  • Cognitive disabilities
  • Problem behaviours

40

Which nucleus in the hypothalamus senses a rise in blood glucose after a meal is taken?

Venteromedial hypothalamic area

41

Where is the appetite stimulating (orexigenic) pathway found in the hypothalamus?

It is found in the venteromedial area of the arcuate nucleus

42

What hormones are released by the small intestine and pancreas after a meal and have been linked with the feeling of satiety?

  • Cholecystokinin
  • Bombesin
  • GLP-1
  • Enterostatin
  • Somatostatin
  • Glucagon
  • Insulin

44

How is the Vagus nerve activated following a meal?

  • It is activated by stomach distention
  • Cholecystokinin also activates the Vagus nerve

45

Besides α-MSH, what other appetite related protein binds to the Mc4 receptor, and what effect does the binding have?

  • AgRP and it inhibits the recepetor, which is the opposite function to α-MSH

46

Where in the brain does leptin exert it's effect?

The arcuate nucleus of the hypothalamus

47

What effects does endocannabinoid activation have on the hypothalamic control of hunger?

It enhances the orexigenic pathway through down-regulation of corticotropin-releasing hormone (CRH) and inhibits Mc4 receptor

This all leads to the feeling of hunger --> "Munchies"

48

What factors can increase the basal metabolic rate?

  • Hyperthryroidism
  • Cold
  • Regular exercise
  • DiseaseFever -> 12/13% increase for 1 degree rise in temp