Histology of the GI tract Flashcards
What are the 4 basic types of tissue?
- Epithelial tissue – tissue on the surface
- Connective tissue – ‘space filling’ tissue e.g. blood, bone
- Muscle tissue – contraction, movement
- Nervous tissue – integrates and coordinates
What are the 4 layers of the gut tube?
Mucosa - epithelium, lamina propria, musularis mucosa
Submucosa
Muscularis externa - inner circular, outer longitudinal
Adventitia/serosa
What are the 3 layers of the mucosa?
Epithelium
Lamina propria
Muscularis mucosae
What orientation is the muscle layers in the muscularis externa?
Inner circular
Outer longitudinal
What epithelium is present in the oesophagus?
Stratified squamous non-keratinised epithelium
What type of muscle is found throughout the oesophagus?
- Upper 1/3 - skeletal
- Middle 1/3 – smooth+ skeletal
- Lower 1/3 - smooth
Where are the glands found in the stomach wall?
In lamina propria of mucosa
What are peyers patches?
Clusters of lymphocytes, stain purple
How many layers of muscle are there in the muscularis externa of the stomach?
3 layers:
- inner oblique
- middle circular
- outer longitudinal
What glands are found in the duodenum and where in the wall are they?
Brunners glands - responsible for alkalisation of stomach contents, found in submucosa
What are the crypts of leiberkuhn and where are they found?
Crypts of Leiberkuhn –Gland found in intestinal lining of small intestine and colon. The glands and intestinal villi are covered by epithelium which contains multiple types of cells: enterocytes (absorbing water and electrolytes), goblet cells (secreting mucus), enteroendocrine cells (secreting hormones), cup cells, tuft cells and, at the base of the gland, Paneth cells and stem cells. These cells are not all present in the colon.
What are enterocytes responsible for?
Absorbing water and electrolytes
What are Paneth cells?
Cells in intestines that secrete anti-microbial peptides
