Second Set (2)

Question 1

Energy Balance

Answer 1

1. Increasing fat storage promotes leptin release from adipocytes.
2. Hormones released from the gut during feeding convey hunger (ghrelin), satiety (CCK) and satiation (PYY 3-36)
3. In the ARC, hormones that secrete POMC / CART products promoted feeding and those that secrete NPY / AgRP inhibit it.

Question 2

Bone mineral homeostasis

Answer 2

1. Members of the Vitamin D family are converted into calcifediol in the liver then calcitriol in the kidney.
2. Calcitriol increases plasma Ca2+ by mobilising it from the bone.
3. Calcitonin secreted from the thyroid reduced Ca2+ reabsorption by inhibiting osteoclast activity.

Question 3

Incretins

Answer 3

1. GIP: Gastric Inhibitory Polypeptide (GIP), also known as glucose-dependent insulinotropic peptide, is a hormone primarily secreted by the enteroendocrine K-cells in the small intestine, particularly the duodenum and jejunum. Stimulates insulin secretion from pancreatic beta cells and promotes fat deposition by increasing triglyceride synthesis and storage in adipose tissue.
2. GIP-1: Glucagon-like Peptide-1 is a hormone produced by enteroendocrine L-cells in the small intestine. In addition to stimulating insulin release it also inhibits glucagon secretion and slows down gastric emptying.

Question 4

CCK

Answer 4

1. Cholecystokinin (CCK) is a peptide hormone produced in the small intestine and the brain, particularly in the gastrointestinal tract by I cells in the duodenum and jejunum.
2. CCK functions as a satiety signal, meaning it induces feelings of fullness and reduces appetite.
3. CCK acts on receptors, particularly CCK1 receptors (also known as CCK-A receptors)