Cell types/histology - Bendiak

Question 1

Cholecystokinin.

Source? Action? Regulation?

Answer 1

Source: I cells in the duodenum/jejunum

Action: INcrease pancreatic secretions, INcrease gallbladder contraction, Relax sphincter of Oddi, DEcrease gastric emptying

Regulation: Increased by fatty acids, amino acids

Question 2

Gastrin.

Source? Action? Regulation?

Answer 2

Source: G cells in the ANTRUM of the stomach

Action: INcrease H+ secretion, INcrease gastric motility

Regulation: INcreased by stomach distension, vagal stimulation, pH increase. DECreased by pH less than 1.5

Question 3

Glucose-dependent insulinotropic peptide

Answer 3

Source: K cells (duodenum, jejunum)

Action: Exocrine–> decrease gastric H+ secretion
Endocrine–> increase insulin release

Regulation: INcreased by fatty acids, amino acids, oral glucose

Question 4

Secretion of ____ is increased by chronic PPi use and in Zollinger-Ellison syndrome.

Answer 4

Gastrin.

Question 5

Motilin

Source? Action? Regulation?

Answer 5

Source: small intestine

Action: Produces migrating motor complexes (MMCs)

Regulation: increased during fasting state.

[Erythromycin is a motilin receptor agonist, and increases the rate of peristalsis]

Question 6

Secretin

Source? Action? Regulation?

Answer 6

Source: S cells (duodenum)

Action: INcrease pancreatic HCO3 secretion, INcrease bile secretion, DEcrease gastric acid secretio

Regulation: Increased by fatty acids in the lumen of the duodenum

Question 7

Somatostatin

Source? Action? Regulation?

Answer 7

Source: D cells (pancreatic islets, GI mucosa)

Action: DEcrease gastric acid secretion, pepsinogen secretion, pancreatic secretion, gallbladder contraction, insulin and glucagon release

Regulation: INcreased by acid, DEcreased by vagal stimulation

Question 8

Loss of nitric oxide is implicated in which disorder of upper GI motility?

Answer 8

Achalasia.

Loss of NO decreases relaxation of LES.

Question 9

Vasoactive intestinal polypeptide (VIP)

Source? Action? Regulation?

Answer 9

Source: Parasympathetic ganglia in sphincters, gallbladder, small intestine

Action: INcrease water/electrolyte secretion, relaxation of smooth muscle and sphincters

Regulation: INcreased by vagal stimulation and distension, decreased by adrenergic input

Question 10

A tumor that causes a constallation of Copious Watery Diarrhea, Hypokalemia, and Achlorhydria?

Answer 10

VIPoma - non-α, non-β islet cell pancreatic
tumor that secretes VIP. (WDHA syndrome)

Watery Diarrhea
Hypokalemia
Achlorhydria

Question 11

Gastric acid

Source? Action? Regulation?

Answer 11

Source: Parietal cells (stomach)

Action: decrease stomach pH

Regulation:
INcrease by Histamine, Gastrin, Ach
DEcrease by somatostatin, GIP, prostaglandin, secretin

Question 12

Tumor that causes high levels of acid secretion and ulcers refractory to medical therapy.

Answer 12

Gastrinoma: gastrin- secreting tumor

Question 13

Pepsin

Source? Action? Regulation?

Answer 13

Source: Chief cells

Action: Protein degradation

Regulation: Increased by vagal stimulation, local acid

Question 14

Glands in the duodenum that secrete bicarb?

Answer 14

Brunner glands. Located in the duodenal submucosa.

Hypertrophy seen in peptic ulcer disease.

Question 15

HCO3−

Source? Action? Regulation?

Answer 15

Source: Mucosal cells (stomach, duodenum, salivary glands, pancreas) and Brunner glands (duodenum)

Action: Neutralize acid

Regulation: Increased by pancreatic and biliary secretion with secretin

Question 16

3 secretory cell types found in the duodenum?

Answer 16

I cells –> CCK
S cells–> secretin
K cells–> GIP

Question 17

3 secretory cell types found in the antrum?

Answer 17

G cells
Mucous cells–> Mucus
D cells–> somatostatin

Question 18

Where are chief cells and parietal cells found?

Answer 18

Body of the stomach.

Question 19

Serotonin and Substance P are secreted by what cell type? Where are these cells found? What is the effect of each?

Answer 19

EC cells.

Stomach, small and large intestine

Increase peristaltic movement

Question 20

ECL cells secrete _____. They are found in the ___.

Answer 20

Histamine. Found in the stomach.

Question 21

_______ in the small intestine contain large eosinophilic granules, which contain antibacterial peptides called defensins, in addition to lysozyme and phosopholipase.

Answer 21

Paneth cells

Question 22

Brunner’s glands are only found in the _____ and release their contents into the crypts. Brunner’s glands secrete _____.

Answer 22

duodenum; large quantities of bicarbonate to neutralize the acid arriving through the pyloric sphincter

Question 23

Arrange by # of goblet cells (most to least): jejunum, ileum, duodenum

Answer 23

Ileum>Jejunum>Duodenum

Question 24

Arrange by amount of lymphatic tissue (most to least): jejunum, ileum duodenum

Answer 24

Ileum»Jejunum>duodenum

Question 25

Trypsinogen (pro-trypsin) is activated by a proteolytic cleavage by the enzyme ______ that is not secreted
by the pancreas but is a membrane anchored enzyme in
the apical plama membrane of duodenal
digestive/absorptive cells (the epithelial enterocytes).
Trypsin in turn activates the other zymogens by
proteolysis.

Answer 25

enterokinase

Question 26

Two other enzymes, ____ and ____ are synthesized in the ACTIVE form in the pancreas.

Answer 26

amylase (that degrades starch to glucose and maltose) and ribonuclease (that cleaves RNA)

Question 27

98% of pancreatic function is dedicated to (endocrine or exocrine) function.

Answer 27

Exocrine (98%)–> acinar cells

Endocrine–> Islets of Langerhans