132b - Histology of the GI System Flashcards
Which parts of the GI tract contain goblet cells?
Small and large intestine
(more abundant in the large intestine)
Where in the GI tract is this?
Ileum
Has Peyer’s Patches (lymphoid follicles)
Which part of the stomach stains brown with an immunostain for gastrin?
Why?
Antrum
- Gastrin is produced by G cells
- Only found in the antrum of the stomach
What common feature is present in the regions of the digestive system covered by stratified squamous epithelium?
They are closely associated with the ouside environment and stressors
- Oral cavity
- Esophagus
- Anal canal
Where in the GI tract are Rokitansky-Aschoff sinuses found?
What are they?
Gallbladder
Invaginations of the gallbladder epithelium (simple columnar) that extend toward the smooth muscle layer
What is secreted by the Islets of Langerhans of the pancreas? (3)
- Insulin
- Glucagon
- Somatostatin
What is the histologic hallmark of the duodenum?
Brunner glands
Describe the flow of bile
- 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
Where in the GI tract is this?
Stomach - gastric surface epithelium
- Simple columnar epithelium
- No goblet cells
- Goblet cells in the stomach = intestinal metaplasia
Which structure is the bile duct?
A
- Slightly bigger than the artery, apparently
What are the 3 layers of the mucosa?
Epithelium
Lamina propria
Muscularis mucosa
What is the difference between adventitia and serosa?
- 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
What color will chief cells be on an H&E stain?
Chief cells will be purple/blue (basophilic)
Which organs of the GI tract contain secretory mucosa?
Stomach
(The mucosa secretes enzymes; in the SI, enzymes are secreted by the pancreatic cells, not the mucosa)
What color will parietal cells be on an H&E stain?
Why?
Parietal cells will be pink (eosinophilic)
Pink = many mitochondria;
parietal cells need these to make ATP for the H+/K+ ATPase