GI Exam Review (Rana's portion) Flashcards by Stephen Murata

Which of the following is part of the GI mucosal layer?

A. Submucosa

B. Circular muscle

C. Longitudinal muscle

D. Muscularis mucosa

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Which of the following is part of the submucosal layer?

A. Epithelium

B. Lamina propria

C. Muscularis mucosa

D. Serosa

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What are the 3 types of regulatory control?

A. Neural B. Endocrine C. Paracrine

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What system is solely under neural control?

Salivary secretions

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Where do segmental contractions predominate?

A. Small intestine

B. Large intestine

C. Esophagus

D. Gastric antrum

E. A and B

E. Small & large intestine

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Where do peristaltic contractions predominate?

A. Pharnyx

B. Esophagus

C. Gastric antrum

D. Small & large intestine

E. All of the above

E. All of the above note: small/large intestines exhibit both peristaltic and segmental contractions

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Which of the following are secreted in response to a meal?

A. Insulin

B. Motilin

C. Glucagon

D. B and C

A. Insulin

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Which of the following are secreted in response to fasting?

A. Insulin

B. Motilin

C. Glucagon

D. B and C

D. Motilin and glucagon

Note: this question is supposed to trip you up with motilin. She mentioned it in the review session. Motilin promotes peristalsis between meals to clear the digestive tract. After a meal, motilin is suspended.

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Which of the following constricts, in response to reverse peristalsis?

A. LES

B. UES

C. Pyloric sphincter

D. Sphincter of Oddi

B. UES

Note: remember UES constricts during retching?

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Which of the following salivary enzymes plays a role in ORAL HYGIENE?

A. alpha-amylase

B. Lysozyme

C. Mucin

D. Lipase

E. Kallikrein

B. Lysozyme

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At either high or low secretory rates, saliva will be ________ compared to plasma.

A. Isotonic

B. Hypotonic

C. Hypertonic

B. Hypotonic.

But the slower the flow rate, the more time for net absorption of Na/Cl (MORE) and secretion of K+/HCO3- (LESS)

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Why is HCO3- concentration indifferent to salivary flow rate? See diagram

It’s under direct parasympathetic control

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Which of the following stimuli PROMOTE salivary secretion?

A. Dehydration

B. Fear

C. Sleep

E. Nausea

(Saliva tastes salty when you’re about to throw up, right?)

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You prescribe atropine to manage John’s dysphagia. He later complains of dry mouth. Why?

See image

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What relaxes the LES?

A. VIP

B. ACh

C. Progesterone

D. A and C

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In the esophageal phase, the primary and 2ndary peristaltic contractions are initiated by ______ and ______, respectively.

A. Swallowing reflex, enteric nervous system

B. Enteric nervous system, swallowing reflex

A. Swallowing reflex, enteric NS

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A biopsy of a patient with chronic GE reflux may have intestinal metaplasia. Which of the following cell types will likely NOT be found in his esophageal biopsy?

A. Goblet cells

B. Columnar epithelial cells

C. Stratified squamous epithelia

D. Esophageal cardiac cells

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Which of the following is an ESSENTIAL FACTOR that is secreted by parietal or oxyntic cells?

A. HCL

B. Intrinsic Factor

C. B12

E. Gastrin

B. Intrinsic factor

Please identify the MISMATCHED cell/organ pair:

A. Goblet cells - stomach

B. Kupfer cells - liver

C. Cholangiocytes - bile duct

D. Goblet cells - intestines

Which of the following drugs would inhibit the BLUE TRANSPORTER depicted here?

A. Omeprazole

B. Ranitidine

C. Cimetidine

D. 6-Mercaptopurine

The mucus layer of the stomach is protective against:

A. H+

B. Pepsinogen

C. Pepsin

D. A and C

D. H+ and Pepsin

Vagovagal reflex promotes which of the following?

A. Receptive relaxation

B. Gastrin release

C. Gastric motility

D. All of the above

Cimetidine will block

A. Histamine effects on parietal cells

B. Histamine-potentiated effects of ACh and Gastrin

C. Gastrin effects on parietal cells

D. Gastrin-postentiaed effects of Histamine and ACh

E. A and B

F. C and D

E. A and B

Know this diagram COLD

What type of neuron is secreting GRP? A. CN X B. Enteric neuron C. Sympathetic post-ganglionic D. GRP is paracrine

Somatostatin is a protective mechanism that is activated when stomach pH drops too low. Which of the following is the DIRECT effect of somatostatin? A. Suppression of cAMP cascade B. Suppression of IP3/Ca2+ cascade C. Suppression of gastrin release from G-cell D. Suppression of histamine release from ECL cell

C. Suppression of gastrin release from G-cell Note: cAMP cascade suppression is the INDIRECT effect

Unlike duodenal ulcers, gastric ulcers are often the result of A. Mucosal barrier defects B. Hyper secretion of H+ C. Undersecretion of HCO3- D. Pyloric sphincter problems

A. Mucosal barrier defect

Which of the following is NOT a function of CCK? a. Relaxes sphincter of Oddi b. Contracts bile duct c. Promotes pancreatic acinar secretion (enzymes) d. Inhibits gastric emptying e. Promotes pancreatic ductal secretions

E. because secretin does this

What is NOT one of the major factors that inhibit/slow gastric emptying? A. Low pH in duodenum B. High pH in duodenum C. Amino acids in duodenum D. Fat in duodenum

Let's dive deeper into the mechanism of secretin-mediated HCO3- secretion, by pancreatic ductal cells. What are the 2 sources of ductal HCO3- secretion? A. imported by NBC-1 co-transporter on basolateral side B. Generated intracellularly by carbonic anhydrase C. CFTR D. A and B

D. A and B

How does secretin regulate DUODENAL (not GASTRIC) pH, when it drops below ~4.5? A. Promotes pancreatic ductal secretion of HCO3- B. DIRECT action inhibits G-cell secretion of gastrin C. INDIRECT action suppresses cAMP cascade in stomach parietal cells D. B and C

A. Promote pancreatic ductal HCO3- secretions BE CAREFUL. Do not mix up SECRETIN (from S-cells) with SOMATOSTATIN (from D-cells) which relate with choices B and C.

Unlike the alkaline tide in gastric venous blood, the pancreatic venous blood is...

Acidified

What stimulates the release of CCK from I-cells? A. Monitor peptide from pancreatic acinar cells (under neural control) B. Paracrine release of CCK-RP in response to FA and AA C. Direct stimulation of I-cells by FA/AA E. All of the above

E. All of the above. Know this diagram cold. There is an involved story here. Basically trypsin clears CCK-RP and MP, but after a protein meal, trypsin will be "tied up" and CCK will be released. Don't have time now but make sure you review this.

Where are the majority of unconjugated bile acids re-absorbed? A. Active transport into enterohepatic circulation via ASBT transporters in distal ileum B. Passive transport in colon

BE CAREFUL. B. Passive transport in colon because I said UNCONJUGATED. Conjugated bile acids use ASBT.

What is the major site of Na+ absorption in the small intestine? A. Duodenum B. Jejunum C. Ileum

B. Jejunum Note the differences between ileum and jejunum, just in case. Jejunum reabsorbs NaHCO3. Ileum absorbs NaCl. Both use carbonic anhydrase. Note: Na+ is cotransported with sugar or AA. Defect in this transport can cause osmotic diarrhea and Na+ absorption problems.

Which is required for transport of Ca2+ across the basolateral epithelial membrane in intestine? A. ATP B. 1,25(OH)2-D3 from kidney C. Calbindin D-28K D. A and B

Vitamin B12 (aka methylcobalamine) is required for conversion of 5 methyl-THF to THF, which is necessary for purine and pyrimidine synthesis. B12 is RELEASED from food in the STOMACH with the help of which of the following? A. Gastrin (from G-cells) B. Pepsin (from Chief cells) C. Intrinsic factor (from parietal cells) D. HCL (from parietal cells)

BE CAREFUL. Just because you see B12, don't just automatically jump to intrinsic factor. B. Pepsin

Vitamin B12 (aka methylcobalamine) is required for conversion of 5 methyl-THF to THF, which is necessary for purine and pyrimidine synthesis. B12 is ABSORBED in the ILEUM if it complexes with ______________ in the DUODENUM. A. Gastrin (from G-cells) B. Pepsin (from Chief cells) C. Intrinsic factor (from parietal cells) D. HCL (from parietal cells)

During the COLONIC PHASE, arrival of lipids can suppress intestinal secretion and motility, via A. CCK release B. Somatostatin C. YY release (ileal brake) D. Secretin

C. YY ileal brake

By what transporter is Na+ reabsorbed into the distal colon? A. ENaC B. SGLT1 C. Na+/aa co-transporter D. SMCT1

A. ENaC - CORRECT B. SGLT1 - this is intestinal C. Na+/aa co-transporter - intestinal again D. SMCT1 - colonic short FA absorption

What is a key metabolic contribution of enteric bacteria? A. Produces urea B. Produces ammonia C. Makes CCK D. Conjugates of bile acids

B. makes ammonia from bile acids Note: DE-conjugation is done by gut flora.

Which is NOT part of the portal triad? A. Hepatic artery B. Hepatic vein C. Bile duct D. Portal vein

B. Hepatic vein

Which of the following histological "zones" are correctly matched with their description? A. Zone 1 - most sensitive to ischemia B. Zone 2 - intermediate between zone 1 and 2 cells C. Zone 3 - most sensitive to oxidative injury or toxins D. Both A and C are correct

B. Here's the correct matching: Zone 1: 1st damaged by toxins/oxidative damage Zone 2: btwn 1 and 2 Zone 3: 1st damaged by ischemia

Gallstone blockage of which passageway is the most dangerous? A. Common bile duct B. Common hepatic duct C. Cystic duct D. Ampulla of vater (regulated by sphincter of Oddi)

D. Ampulla of vater (Oddi area) will prevent both bile and pancreatic contributions. Note that trypsinogen in pancreas will over-accumulate, promoting self-activation to trypsin in pancreas...bad.

Which enzyme conjugates bilirubin in the liver, and is deficient in NEWBORN JAUNDICE babies? A. HMG-CoA synthase B. UDP glucouronyl transferase C. Thymidylate synthase D. Glutamine PRPP transferase

A. HMG-CoA synthase: ketone body formation **B. UDP glucouronyl transferase: ANSWER** C. Thymidylate synthase: Pyrimidine synthesis (dUMP to dTMP) D. Glutamine PRPP transferase: Purine synthesis committed step (PRPP to 5-phosphoribosylamine)

Which of the following are the direct result of increased vascular resistance in the liver? A. Portal hypertension B. Liver cirrhosis (hyperactive STELLATE cells) C. Hepatic encephalopathy D. Hyperbilirubinemia

a. portal hypertension