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Flashcards in Regulation of Energy Balance Deck (29):
1

What percentage of energy expenditure does basal metabolic rate make up?

65-75%

2

What are the three ways which the body expends energy?

basal metabolic rate, activity (both spontaneous and voluntary), thermogenesis

3

What is the gold standard of measuring energy expenditure?

double labeled water - patient drinks water with oxygen 18 and deuterium and collect urine to look at outcomes

4

What is metabolism proportionate to?

body size

5

How is body weight maintained?

homeostasis - there is a set point

6

Do all subjects who are force fed gain the same amount of weight?

No

7

What correlates highly with the amount of fat gain due to force feeding?

activity thermogenesis (fidgeting)

8

Where in the brain is weight controlled?

the hypothalamus

9

What are the two types of neurons relating to weight in the arcuate nucleus?

NPY neurons and POMC neurons

10

Where do neurons in the arcuate nucleus project to?

the paraventricular hypothalamic nucleus and the lateral hypothalamus

11

What do NPY neurons secrete?

NPY and AGRP

12

What do NPY and AGRP promote?

eating

13

What do POMC neurons secrete?

MSH and CART

14

What receptor does MSH bind to?

MC4

15

What do MSH and CART inhibit?

food intake

16

What hormones are released by the paraventricular hypothalamic nucleus?

oxytocin and CRH

17

What do oxytocin and CRH inhibit?

food intake

18

What hormones are released by the lateral hypothalamus?

orexin and MCH

19

What do orexin and MCH promote?

food intake

20

Where else does the paraventricular hypothalamic nucleus and lateral hypothalamus get input from?

Vagus nerve

21

What modulates the system?

opioids, dopamine and endocannabinoids

22

What else provides peripheral modulation of the system?

higher cortical centres (conscious will), the size of fat stores and the presence of food in the gut

23

What is leptin?

A peptide hormone made in fat cells in proportion to the size of the cell that travels to the brain and is a powerful inhibitor of food intake

24

What is insulin?

A peripheral signal that is a long term inhibitor of food intake

25

How are nutrients involved in food intake control?

Can inhibit food intake

26

How does glucose inhibit food intake?

glucose metabolism leads to the production of malonyl-CoA which inhibits CPT1 preventing the breakdown of LCFA-CoA which inhibits food intake

27

What genes determine obesity?

leptin, leptin receptor, POMC, prohormone covertase 1, MC4R

28

What explains the increase in prevalence of obesity?

epigenitics

29

What are causes of spontaneous weight loss?

endocrine diseases, gastrointestinal diseases, infection, malignancy, anorexia nervosa