Lab9_GItract Flashcards
What are the layers of the stomach?
Mucosa:
- Pits and glands
1. Epithelium (simple columnar epithelium (with surface mucous cells → have mucigen droplets)
2. Lamina propria: loose CT
3. Muscularis mucosa: 2 layers of smooth muscles (inner circular/outer longitudinal)
- Occationaly 3 layers (outer circular)
- Smooth muscle projections in between glands in lamin propria
Subucosa:
- Dense irregular CT
- No glands, but rich in blood vessels, lymphatics & nerves
Tunica Muscular:
- 3 layers of smooth muscle (inner oblique/middle circular/outer longitudinale)
Serosa:
- Thin layer of loose CT covered by a mesothlium (simple squamous epithelium)
WHat is the Pyloric ratio of pits : glands?
Pit has 2x length of glands (2:1)
What is the Body ratio of pits : glands?
Gland is 4x the length of Pits (1:4)
Which cells are seen in the body, but not in the pyloric region?
- Parietal cells
- Zymogenic cells
What are the layers of the small intestine?
Mucosa:
- Crypt and villi
- Epithelium → Simple columnar epithelium with brush border
- Lamina Propria → loose CT
- Muscularis mucosa → 2 layers of smooth muscle (inner circular/outer longitudinal)
Submucosa:
- Dense irregular CT
- Brunner’s glands (mucous) in duodenum only
- Plicae circularis seen in jejunum
Tunica muscularis:
- 2 layers of smooth muscle (inner circular/outer longitudinal)
Adventitia or Serosa:
- Adventitia → dense irregular CT
- Serosa → thin layer of loose CT covered by mesothelium (simple squamous epithelium)
What are all the different cells found in the brush border of the small intestine?
- Enterocytes
- Goblet cells
- Paneth cells
- Crypt base cells
- Enteroendocrine cells
Which cells/glands are found in the submucosa of the small intestine?
Brunner’s glands (mucous) in duodenum only
Plicae circularis seen in jejunum
What are the features of the Ileum?
- No Brunner’s gland
- No visible plicar circularis
- More Goblet cells
- Few Paneth cells
- Crypts and villi appear straight
What are the layers of the large intestine?
Mucosa:
- No villi, only crypts (wich appear very straight in that region, and have no paneth cells, has goblet cells)
- Epithelium → simple columnar and contains mainly goblet cells
- Lamina Propria → Loose Irregular CT (like SI)
- Muscularis mucosa → 2 layers (inner circular/outer longitudinal like in SI)
Submucosa:
- Poorly preserved because very dense
- No place circularis
Tunica muscular:
- Inner circular
- Outer longitudinal (can be modified to form a 3rdlayer that runs the length of the colon) → called taenia coli and functions to strenghten longitudinal contractions
Serosa:
- Thins layer of loose CT covered by mesothelium (simple squamous epithelium)