Histology of the Digestive System Flashcards
What are the layers of the wall of the alimentary canal?
from lumen, outward
Mucosa
Submucosa
Muscularis externa
Serosa or Adventitia
What are the layers of the Mucosa of the Alimentary canal?
Lining epithelium
Lamina Propria
Muscularis mucosae
Lining Epithelium
Superficial layer of the mucosa of the Alimentary canal
Where would the lining epithelium of mucosa be nonkeratinized stratified squamous epithelium?
Regions that need protection:
Mouth, Pharynx, Esophagus, Anus
Where would the lining epithelium of the muscoa be simple columnar epithelium?
Regions of absorption:
Stomach, Small intestines, Large intestines
Lots of tight junctions here
What layer do things need to cross to be “in the body”
Lining epithelium of the mucosa
Lamina propria
Middle layer of mucosa
Loose areolar Connective tissue
Lots of lymphatics here and some glands
Muscularis mucosa
Smooth muscle tissue layer of the mucosa
Submucosa
Dense irregular connective tissue
Binds submucosa for the muscularis externa
Meissner’s Plexus
Lots of myelinated nerve endings in the submucosa
What are the layers of the Muscularis externa
Inner circular layer
Nervouse tissue
Outer longitudinal layer
Inner circular layer of Muscularis externa
Smooth muscle in Muscularis externa
Thickened in sphincters and valves
Contract to close down lumen, and lengthen the GI tract
Nervous tissue of Muscularis externa
In between muscle layers
Location of Mysenteric nerve plexus
Outer layer of Muscularis externa
Smooth muscle
Contracts to dilate the lumen and shorten theGI tract
Serosa and Adventitia
Loose areolar connective tissue
Serosa has a mesothelium on the very outside
Esophagus Mucosa
Nonkeratinized stratified squamous epithelium
Esophageal cardiac glands in lamina propria
Esophagus Submucosa
Dense irregular CT
Connect muscosa to muscularis externa
Contains esophageal glands
Esophagus Muscularis Externa
Skeletal muscle proximally and smooth muscle distally
Moves bolus through GI tract
Esophagus Serosa/Adventitia
Adventitia superior to diaphragm
Serosa inferior to the diaphragm
Esophagus Glands
Esophageal glands proper
Esophageal Cardiac glands
Esophageal glands proper
In the submucosa
Esophageal cardiac glands
In the lamina propria