Upper GI Flashcards
What are the 4 layers of GI tract cells
1) mucosa
- epithelium
- lamina propria
- Muscularis mucosae
2) Submucosa
3) Muscularis externa
4) Adventitia or serosa
What are the layers of the muscularis mucosae?
inner circular & outer longitudinal
What are the layers of the muscularis externa
inner circular and outer longitudinal
What nerve plexus’s does the Eteric nervous system contain?
Myenteric plexus
submucosal plexus
Where is the myenteric plexus?
What does it regulate
between layers of muscularis externa
regulates peristalsis
Where is the submucosal plexus?
What does it regulate?
In the submucosal layer
regulates glandular secretion, blood flow, muscularis mucosae
Where is the visceral afferents?
What does it monitor?
in the submucosal plexus
monitors chemistry and mechanical stimulation
What is achalasia and what does it prevent?
dysfunction of myenteric plexus
prevents relaxation of lower esophageal sphincter
What is Hirschsprung’s disease? “congenital megacolon”
absence of enteric nervous system in a portion of the bowel
What is Barett’s esaphagous
What does it increase the risk of?
chronic insult from gastric secretions (GERD/Frequent vomiting)
metaplastic columnar epithelium w/ goblet cells replaces SSE
Increases the risk of adencarcinoma
Heliobacter Pylori is resistant to what?
What does it do?
What does it result in?
Resistant to HCL
Colonizes surface mucous layer and indirectly stimulates parietal cells to secrete HCL
Results in Gastric ulcers
What type of cells do gastric pits have?
What type of cells do they have?
How often are these cells replaced?
Simple columnar Epithelium
surface mucous cells
-replaced every 5-7 days
Isthmus =
stem cells
what cells do neck gastric glands have?
What do those cells secrete?
have parietal cells which
secrete HCL and Gastric intrinsic factor
Have mucous neck cells which
secrete Lysosome and antibacterial
what cells do base gastric glands “chief cells” have?
What do those cells secrete?
pepsinogens
Converted into pepsin by HCL
What is the function of enteroendocrine cells
secrete hormones
What does this describe?
shallow pits
coiled glands
Surface mucous cells
Cardiac glands
What does this describe?
deep pits
Mucous neck cells
Pyloric glands
Describe the muscularis externa of the esaphagous
upper 1/3: stratified
middle 1/3: stratified and smooth
lower 1/3: smooth
Where can adventitia be found in the esaphagous?
thorasic esaphagous
Where can serosa be found in the esaphagous?
abdominal esaphagous
Esaphagous mucosa: type of cell
stratified squamous (resist abrasion)
Esaphagous lamina propria: location and secretion
Cardiac glands (proximal and distally) secrete neutral mucous
Esaphagous muscularis mucosae:
longitudinal
