132b - Histology of the GI System

Question 1

Which parts of the GI tract contain goblet cells?

Answer 1

Small and large intestine

(more abundant in the large intestine)

Question 2

Where in the GI tract is this?

Answer 2

Ileum

Has Peyer’s Patches (lymphoid follicles)

Question 3

Which part of the stomach stains brown with an immunostain for gastrin?

Why?

Answer 3

Antrum

• Gastrin is produced by G cells
• Only found in the antrum of the stomach

Question 4

What common feature is present in the regions of the digestive system covered by stratified squamous epithelium?

Answer 4

They are closely associated with the ouside environment and stressors

• Oral cavity
• Esophagus
• Anal canal

Question 5

Where in the GI tract are Rokitansky-Aschoff sinuses found?

What are they?

Answer 5

Gallbladder

Invaginations of the gallbladder epithelium (simple columnar) that extend toward the smooth muscle layer

Question 6

What is secreted by the Islets of Langerhans of the pancreas? (3)

Answer 6

• Insulin
• Glucagon
• Somatostatin

Question 7

What is the histologic hallmark of the duodenum?

Answer 7

Brunner glands

Question 8

Describe the flow of bile

Answer 8

• Produced by hepatocytes
• -> R and L hepatic ducts
• -> Common hepatic duct
• -> Cystic duct
• -> Gallbladder
  
  • Stored here until it is needed
• -> Cystic duct
• -> Common bile duct
• -> Through the Ampula of Valter
• -> Sphincter of Oddi
• -> Duodenum

Question 9

Where in the GI tract is this?

Answer 9

Stomach - gastric surface epithelium

• Simple columnar epithelium
• No goblet cells
  
  • Goblet cells in the stomach = intestinal metaplasia

Question 10

Which structure is the bile duct?

Answer 10

A

• Slightly bigger than the artery, apparently

Question 11

What are the 3 layers of the mucosa?

Answer 11

Epithelium

Lamina propria

Muscularis mucosa

Question 12

What is the difference between adventitia and serosa?

Answer 12

• Serosa covers the organs that move freely inside a cavity
• Adventitia covers the organs that are bound to the surrounding structures

Both serve as the outermost histologic layer of GI tract organs

Question 13

What color will chief cells be on an H&E stain?

Answer 13

Chief cells will be purple/blue (basophilic)

Question 14

Which organs of the GI tract contain secretory mucosa?

Answer 14

Stomach

(The mucosa secretes enzymes; in the SI, enzymes are secreted by the pancreatic cells, not the mucosa)

Question 15

What color will parietal cells be on an H&E stain?

Why?

Answer 15

Parietal cells will be pink (eosinophilic)

Pink = many mitochondria;
parietal cells need these to make ATP for the H+/K+ ATPase

Question 16

Where in the GI tract is this?

Answer 16

Jejunum

• No Brunner’s glands (duodenum) or Peyer’s patches (ileum)
• Has plica circularis
  
  • Most prominent in distal duodenum and jejunum

Question 17

Where in the GI tract are goblet cells most abundant?

Answer 17

Large intestine

(But found throughout the small and large intestine)

Question 18

Which structure is the hepatic artery?

Answer 18

B

Question 19

What is the histologic hallmark of the Ileum?

Answer 19

Peyer’s patches

Question 20

What is the difference between plica circulares and villi?

Answer 20

• Villi are smaller, core is mucosa
• Plica circulares are larger, core is submucosa

Question 21

Describe the blood flow to and through the liver

Answer 21

• Portal vein (75%) and Hepatic artery (25%) supply the liver
• -> Sinusoids (space between hepatocytes)
  
  • Sinusoids may be blocked by cirrhosis
• -> Central vein
• -> Hepatic vein
• -> Inferior vena cava

Question 22

Which structure is the portal vein?

Answer 22

C

Question 23

Which part of the GI tract contains crypts but no villi?

Answer 23

Large intestine

Question 24

Which strucutre is the hepatic vein?

Answer 24

D