Histology of the GI tract Flashcards
What are the layers present in all layers of the GI
- Mucosa
- Submucosa
- Muscualris propria
- Serosa
What are the layers of the mucosa?
- Epithelium
- Lamina propria
- Muscularis mucosal
Where are secretory mucosa found
In the stomach
Where is absorptive mucosa found?
in the SI
Where is absorptive/protective mucosa found?
In the LI
What feature is characteristic of the SI
villi and crypts
what is the cells are found in the LI
cells which specialise in water absorption and mucous secretion
What kind of epithelium is found in the oesophagus?
why?
Stratified squamous non-keratinised
Deals with large clumps of food
what type of muscle is found in the muscularis external of the oesophagus
Top 1/3rd: SKELETAL
Middle 1/3rd: SKELETAL AND SMOOTH
Bottom 1/3rd: SMOOTH
Why are different types of muscle found in the oesophagus?
Skeletal is used for voluntary control
Smooth is used for in voluntary control
What is found in the submucosa of the oesophagus?
Mucosal glands
What type of epithelium is found in the stomach?
Simple columnar epithelium
What is found in the mucosa of the stomach?
- Lots of glands for digestion- release contents into lamina propria
- Parietal: stain pink as they secrete Hcl
- Chief cells: At base of gland- secrete pepsinogen- a lot darker
- Gastric pits
Is there much lamina propria in the stomach?
NO
Properties of histology of small intestine
GENERAL: -Look for villi -Look for crypts -Look for Peyer's patches Duodenum: Brunner's cells Jejunum:few of Peyer's patches and fewer Brunner's cells Ileum:Many Peyer's patches
What are Peyer’s Patches?
Collection of lymphoid tissue
What type of epithelium is found in the SI?
simple columnar
In what layer at Brunner’s glands and peyers patches found?
In the submucosa
what is the function of Brunner’s glands?
They coat the intestine with a lining of anti-acid lining
What are the large folds which extend into the lumen known as?
Plicae
What kind of muscle is found in the muscularis mucosa fo the SI?
smooth
what kind of cells are found in the surface epithelium of the SI?
Goblet cells which secrete mucin
General feature of LI
- lots of moth like cells- Mucous secreting
- NO VILLI
- thick mucosa
What sort of epithelium is found in the rectum?
Stratified squamous
What is the name of the plexus between the circular and longitudinal muscle called?
Myenteric
What is the name of the plexus in the submucosa
Meissner’s plexus/ submucosal plexus
What is the function of the submucosal plexus
Controls the muscularis mucosa
what is the function of myenteric plexus
controls muscularis externa
What are the 4 different types of mucosa
- Protective: stratified squamous non-keratinised
- Secretory: Lots of glands
- Absorptive: VIlli/ crypts
- Protective/absortive: rectum
