Cell Types And Function

Question 1

What is the function of G cells, what do they secrete and from where?

Answer 1

Secrete Gastrin - found in Antrum of stomach and duodenum

Question 2

What is the function of I cells, what do they secrete and from where?

Answer 2

They secrete CCK - found in duodenum and jejunum

Question 3

What is the function of S cells, what do they secrete and from where?

Answer 3

Secrete Secretin - duodenum

Question 4

What is the function of D cells, what do they secrete and from where?

Answer 4

Secrete Somatostatin- pancreatic islets and GI mucosa

Question 5

What is the function of Gastric parietal cells, what do they secrete?

Answer 5

Secrete Gastric acid and Intrinsic Factor

Question 6

What hormones stimulate pancreatic secretion?

Answer 6

CCK - stim. both the pancreas and gallbladder (I cells)
Secretin- stimulates bicarbonate secretion (S cells)
Not hormone:
Acetylcholine from CN X - vagus nerve

Question 7

What enzyme catalyzes the rate-limiting step in carbohydrate digestion?

Answer 7

Oligosaccharide hydrolases found at the intestinal brush border

Question 8

An alcoholic patient diagnosed with alcoholic hepatitis receives lab values with increased AST/ALT. What is the hallmark feature of this disease in terms of lab ratios, and why is one different from the other?

Answer 8

AST is 2x higher to ALT, and this is because alcohol depleted levels of ALT due to B6 deficiency seen in alcohol metabolism.

“A Scotch and Tonic”

Question 9

If hepatocytes can no longer metabolize toxins and ammonia, what pathology is at hand with the following clinical features:
-confusion, delirium, and hypersomnia
-coma, death
-Asterixis: Px extends arms + wrists out, and hands begin to flap, bc they can’t maintain wrist extension.
-Fetor hepaticus (musty odor): aka breath of death
What is the treatment as well?

Answer 9

Hepatic encephalopathy

Tx- Diuretics, beta-blockers (nadol or propranolol), Vitamin K, and lactulose

Question 10

What defect causing pathology is at hand: Autosomal recessive, defect in enzyme ATP7B—> impaired excretion of Cu2+ into bile, and impaired conversion of Cu2+ to ceruloplasmin —> low levels of ceruloplasmin are Dx criteria for disease. Will cause cirrhosis, basal ganglia degeneration, Parkinson symptoms, hepatic encephalopathy, hemolytic anemia, and increased risk for HCC.

Answer 10

Wilson Disease —> no copper excretion leads to copper deposits in liver, brain (dementia), cornea, kidneys (Fanconi Sd), and joints. In eyes —> Kaiser-Fleischer rings.

Question 11

Patient presents with impaired ability to protect organs from elastase. Autosomal recessive—> Early-onset panacinar emphysema and cirrhosis. Classically, Px looks waaaaaay too young to have emphysema. What is the deficient substance?

Answer 11

Alpha1-antitrypsin deficiency.

Question 12

What do K cells produce and from where?

Answer 12

Glucose dependent insulinotropic peptide - duodenum and jejunum

Question 13

Small intestine produces migrating motor complexes called what?

Answer 13

Motilin

Question 14

Parasympathetic ganglia in sphincters, gallbladder, and small intestine produce what? It increases water and electrolyte secretion; it increases relaxation of intestinal smooth muscle and sphincters

Answer 14

Vasoactive intestinal polypeptide

Question 15

Chief cells produce this for protein digestion… production is from where?

Answer 15

Pepsin - stomach

Question 16

Secreted from parietal cells - vitamin B12 binding protein; what is it and production is from where?

Answer 16

Intrinsic factor- stomach

Question 17

Stomach biopsy reveals neutrophils above the basement membrane, loss of surface epithelium, and fibrin-containing purulent exudate.

Answer 17

Acute gastritis

Question 18

What is the name of the tumor that has metastasized from the GI tract (Adenocarcinoma) to the left supraclavicular lymph node?

Answer 18

Virchow Node - histology will show tissue with a “signet ring” cell.

Question 19

What is the name of the tumor that has metastasized from the GI tract (Adenocarcinoma) to a periumbilical node?

Answer 19

Sister Mary Joseph nodule - histology will show tissue with a “signet ring” cell.

Question 20

What is the name of the tumor that has metastasized from the GI tract (Adenocarcinoma) to the ovary?

Answer 20

Krukenberg Tumor - histology will show ovarian tissue with a “signet ring” cell.

Consider also with signet ring, Lobular Carcinoma in situ of the breast.

Question 21

Stomach biopsy reveals lymphoid aggregates in the lamina propia, columnar absorptive cells, and atrophy of glandular structures.

Answer 21

Chronic gastritis

Question 22

Diffuse thickening of gastric folds, elevated serum gastric levels despite secretin stimulation test; biopsy reveals glandular hyperplasia without foveolar hyperplasia.

Answer 22

Zollinger-Ellison Syndrome

May be associated with MEN I

Question 23

What 3 substances stimulate the release of gastrin secretion?

Answer 23

• Phenylalanine
• Tryptophan
• Calcium

Question 24

In histology if you see a mucin filled cell with a peripheral nucleus, you have what?

Answer 24

Signet ring cell —> (gastric cancer, LCIS)

Question 25

K cells (found in duodenum and jejunum) produce what substance? What is it’s purpose?

Answer 25

Glucose-dependent insulinotripic peptide
Exocrine: decreases H+ secretion
Endocrine: increase release of insulin
(Aka gastric inhibitory peptide)

Question 26

What is the role of the Crypts of Lieberkühn and where are they found?

Answer 26

Found in the duodenum, and contain: stem cells that replace enterocytes/goblet cells, Paneth cells that secrete defensins, lysozyme, and TNF

Question 27

What is the role of Brunner Glands?

Answer 27

Cells of submucosa that secrete bicarbonate

Question 28

What is the name of the tumor that has metastasized from the GI tract (Adenocarcinoma) that is found during a digital rectal exam (palpable mass) suggesting metastasis to rectouterine pouch (Pouch of Douglas)??

Answer 28

Blúmer shelf