Topic 15: Digestive System - GI Tract Histology Flashcards
What are the four basic layers of the GI tract?
- Mucosa
- Submucosa
- Muscularis Externa
- Serosa (or adventitia)
What are the 3 layers of mucosa?
- epithelium with numerous goblet cells
- lamina propria
- muscular mucosa
Where can you find the stratified squamous epithelium layer of mucosa? (4)
- mouth
- pharynx
- esophagus
- anal canal
Where can you find the simple columnar epithelium layer of mucosa? (3)
- stomach
- small and large intestine
- rectum
What tissue is the lamina propria of mucosa made of?
areolar CT
What does the lamina propria of the mucosa contain? (3)
- blood
- lymph vessels
- lymph nodules/tissues (immune)
What is the muscular mucosa made of? (2)
- smooth muscle
- allows movement of mucosa
What type of tissue is submucosa?
areolar CT
What does the submucosa contain?
- blood
- lymphatic vessels
- submucosal nerve plexus
What type of muscle is the muscularis externa made of?
- smooth muscle
What is the inner and outer layer of the muscularis externa?
- inner circular layer
- outer longitidinal layer
What is between the two layers of the muscularis externa?
myenteric nerve plexus
What does contraction of the muscularis externa cause?
- motility ( mixing + movement)
What does the serosa (adventitia) contain?
- cavity (lumen)