Intestine Endocrine Cells

Question 1

I Cells

Answer 1

• Make CCK
• stimulated by fats and proteins in lumen of duodenum –> CCK in CNS –> vagus stimulation –> secretion of enzymes by pancreas

Question 2

S Cells

Answer 2

• Make secretin

- stimulated by acid in lumen of duodenum –> water and bicarb secretion by pancreas

Question 3

D1 Cells

Answer 3

• Makes somatostatin
• inhibits parietal, chief, G cells and ECL cells in stomach
• inhibits growth hormone and TSH from pituitary
• inhibits insulin and glucagon secretion from pancreas

Question 4

Mo Cells

Answer 4

• Make motilin

- secreted during fasting state –> stimulate MMC/upper gut motility

Question 5

GIP

Answer 5

(glucose dep insulinotropic peptide)

• stimulated by lumenal glucose in duodenum and jejunem –> induces insulin secretion from pancreas and inc action of LpL

Question 6

L Cells

Answer 6

• Make enteroglucagon
• stimulated when glucose still in lumen of ileum and colon –> hepatic glycogenolysis/glucogenesis + ketogenesis and lipolysis (as if so much glucose in intestine that there must not be enough in blood) and dec gut motility

Question 7

Peptide YY

Answer 7

released when incompletely digested fats in ileum (“ileal brake”) and colon –> satiety to hypothalamus and dec gut motility (slow down b/c fats should not be making it down this far)

Question 8

Pancreatic Polypeptide

Answer 8

• released by PP cells in pancreatic islet after a meal

- stimulated by food in gut and acts as satiety signal to hypothalamus –> inhibits pancreatic exocrine secretion

Question 9

VIP

Answer 9

from neurons of vagus and myenteric plexus –> inc water and bicarb secretion (of pancreas, Brunner’s glands, SI enterocytes and bile duct cholangiocytes) + relaxes smooth muscle (LES, fundus, sphincter of Oddi) + anti-inflammatory