endocrine final

Question 1

Neuropeptide Y-

Answer 1

produces hyperphagia, weight gain, and obesity. blocking stops hyperphagia. increased MCH

Question 2

agouti

Answer 2

Over expression leads to obesity. secreted in hypothalamus. interacts with PVN and nuclei that triggers LH.

Question 3

melanin concentrating hormone

Answer 3

induces appetite and increases food uptake. knockout mice for MCH become hypophagic (under consume food) inhibited by POMC

Question 4

endogenous endocannabinoids

Answer 4

Anandamide binds to cannabinoid (CB1) receptors stimulates food intake. Stimulates fat formation (lipogenesis). in knockout mice, remove CB1 and the mice become lean.

Question 5

Ghrelin

Answer 5

secreted from stomach, stimulates feeding and decreases after a meal. reduces gastric emptying and sense of satiety (makes you hungry quicker) stimulates NPY and Agouti

Question 6

Galanin

Answer 6

stimulates LH release from pituitary, makes you crave fatty foods. before lunch and dinner. responsible for weight increase in girls at puberty. GAL 1 and GAL 3 act through CAMP and some through GAL2 through PLC

Question 7

leptin

Answer 7

produced by fat cells and is an anorexic signal. blocks release of ghrelin. increases metabolic rates, released when you store fats. binds to Hypothalamus and triggers JAK-STAT pathway. delays puberty. POMC mRNA released

Question 8

POMC (proopiomelanocortin)

Answer 8

receptors for leptin, secretes a-MSH binding to MC3 and MC4 receptors. Taking out MC4 leads to obesity. releases CRH — an anorexic agent. CART also stops intake (cocaine and amphetamine surpasses appetite bc this receptor)

Question 9

intestinal peptide YY

Answer 9

inhibits the release of npy and stimulates msh release

Question 10

pancreatic polypeptide

Answer 10

when the pancrease is secreting panreatic juice it is exocrine, reduces appetite

Question 11

Prolactin releasing peptide

Answer 11

is found to be an appetite supressor in fish and triggors the release of prolcatin

Question 12

What are the general physiological roles for gastrointestinal hormones?

Answer 12

Have a function in the hypothalamic pituitary axis

• Effect appetite,
• secretion of enzymes for digestion from other organs to break down the material to be absorbed.
• stimulates secterion of acids from stomach and bases from the pancreas.
• Regulate ph .
• stimulate smooth muscle contractions.
• Secrete hormones (insulin and glucogon ) from pancreatic islets.

Question 13

What are the three phases controlling gastric secretion?

Answer 13

1- cephalic phase (parasympathetic nervous system) 2-gastric phase (food in tummy) 3- intestinal phase (peptide release)

Question 14

How is gastrin secretion regulated and what are its physiological roles?

Answer 14

• Starvation/ parenteral (fed through IV) reduces gastrin.
• Stimulates Acid secretion, Histamine secretion, Pepsinogen, Mucosal lining, lower Esophageal sphincter to close (acid reflux prevention) relaxes pyloric sphincter, stimulates Pancreatic enzymes release, increases Motor activity of intestine,

Hypergastrinemia = could cause gastric and duodenal ulceration (zollinger-ellison syndrome) tumor that secretes excess acid in stomach. 5% ulcers caused by alcoholics or high asprin intake.

Question 15

secretin

Answer 15

• S cells that lie between crypts (contains stem cells) and villi (do all digestion and absorption, live about 7 days).
• Stimulates pancreatic bicarbonate secretion (to buffer acid from stomach/ slow down digestion), interacts with CCK (to release protease and amylase), secretion is released from acid, causes release of bile (to digest fat),

Question 16

What are the roles of cholecystokinin?

Answer 16

Released in presence of food. Empties gallbladder (stores bile which makes fat digestible), 33 Amino acids long, similar amino acids to gastrin, inhibits stomach emptying, stimulates pancreatic enzyme secretion, stimulates acinar cells on pancreas, relaxes oddi sphincter, acts as a satiety hormone (inhibits ghrelin which triggers hunger)
Has many forms – some shorter half life than others. Larger molecules less easily cleared. Produced in i cells of entire length of intestinal tract. Fatty Acids stimulates release

Question 17

How is it proposed that VIP stimulates insulin secretion?

Answer 17

Causes relaxation of the sphincter of oddi, regulates bile flow,

Question 18

Discuss/diagram the control of the secretion of stomach acid including all hormones involved.

Answer 18

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Question 19

How is gastrin secretion regulated and what are its physiological roles?

Answer 19

Starvation parenteral (fed through IV) reduces gastrine. 
Stimulates acid secretion, histamine secretion, pepsinogen, mucosal lining, lower esophageal sphincter to close (acid reflux prevention) relaxes pyloric sphincter, stimulates pancreatic enzymes release, increases motor activity of intestine, 
Hypergastrinemia = could cause gastric and duodenal ulceration (zollinger-ellison syndrome) tumor that secretes excess acid in stomach. 5% ulcers caused by alcoholics or high asprin intake.

Question 20

What is the role of secretin?

Answer 20

S cells that lie between crypts (contains stem cells) and villi (do all digestion and absorption, live about 7 days).
Stimulates pancreatic bicarbonate secretion (to buffer acid from stomach/ slow down digestion), interacts with CCK (to release protease and amylase), secretion is released from acid, causes release of bile (to digest fat),

Question 21

What are the roles of cholecystokinin?

Answer 21

• Released in presence of food. Empties gallbladder (stores bile which makes fat digestible), 33 Amino acids long, similar amino acids to gastrin, inhibits stomach emptying, stimulates pancreatic enzyme secretion, stimulates acinar cells on pancreas, relaxes oddi sphincter, acts as a satiety hormone (inhibits ghrelin which triggers hunger)
• Has many forms – some shorter half life than others. Larger molecules less easily cleared. Produced in i cells of entire length of intestinal tract. Fatty Acids stimulates release

Elevated CCK = increased anxiety and anorexia of aging

Question 22

oxyntotmodulin

Answer 22

glucagon like polypeptide 1 - (GLP1) reduces appetite and food intake. enhances pancreatic secretion of insulin