Histology of the GIT Flashcards
What is the hierarchical organisation?
- Organism
- Organ system
- Organ
- Tissue
- Cells
What are the 4 basic types of tissue?
- Epithelial tissue: tissue on the surface
- Connective tissue: space filling tissue
- Muscle tissue: contraction, movement
- Nervous tissue: integrates and coordinates
Tissue
A group of cells that work together and perform the same function
What are tissue composed of?
Cells and extracellular substance
What is an organ made up of?
2 or more types of tissue
What are the 4 layers of the gut tube?
- Mucosa
- Submucosa
- Muscularis externa
- Adventitia/serosa
What are the 3 layers of the gut tube mucosa?
- Epithelium
- Lamina propria
- Muscularis mucosae
What are the 2 layers of the gut tube muscularis externa?
- Inner circular
- Outer longitudinal
How can you identify if a gland lies in the LP or inn the submucosa?
Identify if it lies above or belowe the muscularis mucosae
What type of epithelium is in the oesophagus?
Stratified squamous non-keratinised epithelium
What is in the submucosa of the oesophagus?
Mucous glands
How does the muscle differ along the oesophagus?
- Upper 1/3: skeletal
- Middle 1/3: both
- Lower 1/3: smooth
What epithelium is found in the stomach?
Simple columnar
Where are the gastric glands of the stomach located?
Mucosa
How many layers of muscularis externa are there?
3
What are the cells stained pink in the gastric glands of the stomach?
Parietal cells that secrete HCl
Where are the chief cells located in the stomach?
Base of the gastric gland and the secrete pepsinogen
What histological landmarks can be found in the small intestine?
- Villi
- Crypts of Leiberkuhn
- Lymphoid aggregations in the mucosa: Peyer’s patches
What glands are found in the submucosa of the duodenum?
Brunner’s glands
What is the ileum characterised by?
- Villi
- Peyer’s patches
What is absent in the jejunum that is present in other parts of the small intestine?
- Brunner’s glands
- Peyer’s patches
How does the large intestine present histologically?
- Thick mucosa
- Crypts
- Mucous secreting cells
- No villi
What are the main glands in the GIT?
- Salivary glands
- Pancreas
- Liver
How doe glands present histologically?
- Secretory, acinar component
- Roundish structure
- Columnar cells
- Nuclei at the base
- Ducts
How does the pancreas present histologically?
- Islet of Langerhans: endocrine part: no acini
- Exocrine part: pancreatic acini
- Pancreatic duct
How does the liver present histologically?
- Hexagonal structures
- Central vein
- Portal triad at each corner
