111 - Obesity

Question 1

What BMI is obese? What is morbid obesity?

Answer 1

obese = 30
Morbid = 40+

Question 2

What is the only currently licenced drug for obesity?

Answer 2

Orlistat - intestinal lipase inhibitor - can’t absorb TG so you poo it instead.

Question 3

What was wrong with the drug rimonabant in obesity?

Answer 3

Increased suicide risk - a cannabis receptor blocker

Question 4

What new drug class are being trialed in obesity?

Answer 4

GLP-1

Involved in diabetes, causes weight loss and reduces appetite.

Question 5

What are 2 restrictive bariatric surgeries?

Answer 5

Gastric banding
Sleeve gastrectomy (gold standard)

Question 6

What is an example of a malabsorptive bariatric surgery?

Answer 6

BPD with DS - bilio-pancreatic diversion with duodenal switch

• can cause malnutrition
• 90% weight loss

Question 7

What is an example of a combined bariatric surgery?

Answer 7

Gastic bypass LGB

- V common in USA.

Question 8

Where is the ‘set point’ of weight regulated?

Answer 8

hypothalmus

Question 9

Describe the blood glucose feeding circuit

Answer 9

Eat -> increase blood glucose -> Ventromedial hypothalmus turned on -> fullness felt -> stop eating

Stop eating -> low blood glucose -> lateral hypothalmus on -> hunger felt -> eat

Question 10

How is Ghrelin involved in appetite regulation?

Answer 10

Signals hunger
Produced in stomach
Calorie intake stimulates it

Question 11

How is insulin involved in appetite regulation?

Answer 11

It is an adiposity signal
Increase blood glucose - > insulin released, decreased feeding, stimulates the hypothalamus to release anorexigenic peptides

Question 12

How is mood linked to appetitie?

Answer 12

Serotonin is realised in anticipation of a meal - antidepressants that act on serotonin -> feel fullness

Question 13

How is the endocannabinoid system involved in appetite control?

Answer 13

Hedonic + homeostatic role

The active ingredient in cannabis, Delta 9THC stimulates appetite.

Question 14

A deficiency in what causes server early onset obesity?

Answer 14

Leptin deficiency - give leptin, treats them.

Question 15

Describe how leptin is involved in appetite regulation

Answer 15

Increased leptin in blood -> acruate nucleus detects -> anorexogenic peptides are released eg. alpha MSH and CART -> inhibits feeding

Decreased leptin in blood -> arcuate nucleus detects -> Orexigenic peptides released -> NPY and AgRP released -> actives feeding

Question 16

What receptor is activated by alpha MSH and blocked by AgRP?

Answer 16

Melacortin receptor

• involved in 1% of inherited obestiy

Question 17

Which gives more energy when broken down, glucose or fat?

Answer 17

Fat - 50ATP per 100g

glucose only 20ATP per 100g

Question 18

What are the major fuels for cellular respiration?

Answer 18

Glucose, fatty acides, ketone bodies, amino acids, lactate

Question 19

What are minor fuels for cellular respiration?

Answer 19

Fructose, Galactose, Glycerol, Alcohol

Question 20

Where is energy stored in the body?

Answer 20

Individual cells
Liver - glycogen
Depots - fat and protein

Question 21

When you lose weight which stores get used first?

Answer 21

Carbs used rapidly
Tissue protein lost initially
Fat then becomes prodominant fuel

Question 22

After how long fasting is fat used?

Answer 22

24hrs

Question 23

What becomes the gut in embryology?

Answer 23

The yolk sac gets pinched off and surrounded by endoderm

Question 24

When does the oesophagus first form?

Answer 24

Week 7/8

Question 25

When does the duodenum first form?

Answer 25

Week 4

Question 26

When does the yoke sac get pinched off and the first primitive gut get formed?

Answer 26

Week 4

Question 27

What becomes the anal canal/anus?

Answer 27

The cloaca