3.3 Control of body weight

Question 1

What is Ghrelin and when is it high?

Answer 1

Made in the stomach - stimulates hunger

Highest during fasting and levels fall within 1h of food intake

Question 2

What is Ghrelin and when is it high?

Answer 2

Made in the stomach - stimulates hunger

Highest during fasting and levels fall within 1h of food intake

Question 3

What is cholecystokinin and when is it lowest?

Answer 3

Secreted by endocrine cells in the GIT in response to feeding
Lowest during fasting

Question 4

What is GLP-1 and when is it low/high

Answer 4

product of pre-proglucagon in GI and CNS

lowest during fasting and increased by feeding

Question 5

What is peptide YY and when is it high/low

Answer 5

Produced by gut endocrine cells

lowest during fasting and increased by feeding

Question 6

What is Leptin

Answer 6

Hormone made by adipose cells that helps regulate body weight by inhibiting hunger - plasma levels correlate with the amount of adipose tissue mass

Question 7

What are the pancreatic hormones of hunger and how do they work (3)

Answer 7

Amylin: may play a role in decreasing food intake in short term

Insulin: proportionate to the amount of adipose tissue. Insulin may reduce feeding by inhibiting the expression of NPY and enhance effects of CCK

Pancreatic polypeptide: May reduce appetitie and food intake in humans

Question 8

What brain region is involve in homeostatic control of food intake?

Answer 8

The arcurate nucleus

Question 9

What are the two groups of neurones in the arcuate nucleus and what is their role?

Answer 9

NPY and AgRP: stimulate food intake

POMC: oppose food intake

Question 10

where do signals go from the arcuate nucleus and what do they release?

Answer 10

other hypothalamic regions such as the Paraventricular nucleus where TRH, CRH and oxytocin (hunger suppressing) and to the lateral hypothalamus where MCH and orexins are produced (hunger stimulating)

Question 11

What is cholecystokinin and when is it lowest?

Answer 11

Secreted by endocrine cells in the GIT in response to feeding
Lowest during fasting

Question 12

What is GLP-1 and when is it low/high

Answer 12

product of pre-proglucagon in GI and CNS

lowest during fasting and increased by feeding

Question 13

What is peptide YY and when is it high/low

Answer 13

Produced by gut endocrine cells

lowest during fasting and increased by feeding

Question 14

What is Leptin

Answer 14

Hormone made by adipose cells that helps regulate body weight by inhibiting hunger - plasma levels correlate with the amount of adipose tissue mass

Question 15

What are the pancreatic hormones of hunger and how do they work (3)

Answer 15

Amylin: may play a role in decreasing food intake in short term

Insulin: proportionate to the amount of adipose tissue. Insulin may reduce feeding by inhibiting the expression of NPY and enhance effects of CCK

Pancreatic polypeptide: May reduce appetitie and food intake in humans

Question 16

What brain region is involve in homeostatic control of food intake?

Answer 16

The arcurate nucleus

Question 17

What are the two groups of neurones in the arcuate nucleus and what is their role?

Answer 17

NPY and AgRP: stimulate food intake

POMC: oppose food intake

Question 18

where do signals go from the arcuate nucleus and what do they release?

Answer 18

other hypothalamic regions such as the Paraventricular nucleus where TRH, CRH and oxytocin (hunger suppressing) and to the lateral hypothalamus where MCH and orexins are produced (hunger stimulating)

Question 19

What are the short term (meal to meal) regulators of hunger?

Answer 19

Ghrelin, CCK, GLP-1, Amylin, PP, PYY

Question 20

What are the medium to long term regulators of hunger?

Answer 20

Leptin and Insulin

Question 21

What can overide the homeostatic system of hunger?

Answer 21

The Hedonic system - inputs from the cortex and reward pathways in the limbic system related to sight, taste, smell, emotion and social factors

Question 22

What is the order of priority of metabolising macronutrients?

Answer 22

Protein - CHO - Fat

Question 23

What does protein favourably influence?

Answer 23

Satiety, thermogenesis and body composition

Particularly during weight loss programs