Digestive system III Flashcards
Where is the transitonal zone between the esophagus and the stomach?
Cardia
What are the 4 major layers of the glandular stomach?
Tunica mucosa
Tunica submucosa
Tunica muscularis
Tunica serosa
What are the folds of the mucosa and submucosa called in the stomach?
Rugae
What is the epithelium present in the stomach?
Simple columnar
What are gastric pits?
Deep invaginations of epithelium
What are gastric glands?
Glands that open to gastric pits (may be more than 1 per pit)
What is the difference between a rugae and a gastric pit?
Rugae is the gross fold of mucosa and gastric pits are located at apex of rugae
What are mucus neck cells?
Cells located in the neck of the epithelium opening in to the gastric pit
What is the epithelial transition at the margo plicatus
stratified squamous to simple columnar
How much of the lamina propria in the stomach do gastric pits account for in the cardiac region?
1/3 (deep)
WHat is the most important region of the stomach?
Fundus
How much of the lamina propria do the gastric pits account for in the fundus?
1/4 (shallow)
What are the 4 parts of the gastric (fundic) gland?
Isthmus
Neck
Body
Base
What is the isthmus of the gastric gland?
opening of gland to pit
what is the neck of the gastric gland?
constricted area near isthmus
What is the base of the gastric gland?
dilated adenomere
What are the 5 cell types located in the fundic region?
Chief Parietal Mucus Enteroendocrine Germinal
Why do chief cells stain blue?
Lots of acid & RER
What do chief cells secrete?
Pepsinogen
Renin
Gastric lipase
Why do parietal cells stain eosinophilic?
Mitochondria
What do parietal cells produce?
HCl
What stimulates parietal cells to secrete HCl?
Gastrin
Histamine
Cholinergic nerves
What structure in parietal cells extend from the apical plasma lemma to the cytoplasm?
Canaliculi
What is the purpose of the mitochondrial canaliculi?
Intake of H+ and Cl-
What is the purpose of the mucus neck cells in the fundus?
protection from HCl activity
What are examples of Diffuse neuroendocrine system cells?
G cells secrete gastrin
D cells secrete somatostatin
EC cells secrete seratonin and substance P
What are the stem cells of the GI tract?
Germinal cells
Where are germinal cells found?
Neck and bottom of gastric pit
How deep are pits found in the pyloric region?
1/2 lamina propria (deepest)
What structure is present at the gastroduodenal junction?
muscular sphincter
