Appetite And Metabolic Syndrome

Question 1

What does the arcuate nucleus do?

Answer 1

It plays a central role in controlling appetite as it processes signals.

Question 2

Name two signals which promote hunger.

Answer 2

Neuropeptide Y (NPY) and Agouti-related peptide (AgRP)

Question 3

What is the action of Agouti-related peptide (AgRP)?

Answer 3

It promotes hunger and stimulates the arcuate nucleus.

Question 4

What is saiety and what promotes it?

Answer 4

It is the opposite of hunger. It is promoted by POMC which contains both a-MSH and B-endorphin.

Question 5

Name the two hormones which act on the primary inhibitory neurone for appetite.

Answer 5

Insulin and Leptin.

Question 6

Where is Leptin secreted from and what effect does it have?

Answer 6

This stimulates the primary inhibitor neurone and inhibits the primary stimulators neurone. Overall the effect it has is suppression of appetite.

Question 7

What is the difference between anorexigenic and orexigenic?

Answer 7

Anorexigenic is the inhibition of appetite. Orexigenic is the stimulation of appetite.

Question 8

Name the hormone which has a stimulators effect on the appetite stimulators neurone.

Answer 8

Ghrelin, this is secreted when the stomach is empty, and as the stomach fills this stretching leads to inhibition of ghrelin secretion.

Question 9

What is PYY?

Answer 9

This is a short hormone released by the small intestine. It inhibits the exciting neurone and suppresses appetite.

Question 10

What is the role of Amylin?

Answer 10

This is a hormone secreted by the pancreas, and its role is not fully understood but overall it suppresses appetite.

Question 11

What appetite hormone can be associated with common obesity?

Answer 11

Leptin.

Question 12

Define Metabolic syndrome

Answer 12

It is a cluster of dangerous risk factors which are associated with Cardiovascular disease.

Question 13

What are the risk factors for metabolic syndrome?

Answer 13

Central obesity, high fasting blood glucose, insulin resistance, dyslipidaemia (low HDL and high TAG)

Question 14

What is a common consequence of insulin resistance?

Answer 14

Insulin resistance means that cells are less sensitive to insulin, this means that the pancreas produces more insulin due to high blood sugar and so eventually the B cells wear out and this leads to T2DM.

Question 15

What can central obesity lead to?

Answer 15

Hypertension, high cholestrol, hyperglycaemia, T2DM.

Question 16

What lifestyle changes could be suggested as a primary treatment for metabolic syndrome?

Answer 16

Reduce fats and sugary food in diet. Exercise more. Moderate calorie restriction.

Question 17

Why are statins used to treat metabolic syndrome? What other drugs may be used?

Answer 17

These lower LDL concentration in the blood. Hypertensive drugs or anti diabetic drugs may also be used to treat this syndrome.

Question 18

What is the barker hypothesis?

Answer 18

This is that there is an association between low birth weight and adult disease incidence.

Question 19

What is epigenetics?

Answer 19

This means on top of genetics. Methyl groups or other factors bind to DNA or histone tails which leads to activation or suppression of particular genes.

Question 20

Propose why a low birth weight may result in increased adult disease.

Answer 20

If a women has poor nutrition during pregnancy then her child will be prepared for living in this harsh environment. If the child then lives a life of plenty then this can lead to obesity and metabolic syndrome.

Question 21

Where is the appetite control centre located?

Answer 21

In the hypothalamus