Histology of the GI tract Flashcards
What is the hierarchical organisation?
Cells (ultrastructural level)
Tissues (molecular level)
Organ
Organ system
Organism
What is the first question you should ask yourself when looking at a histological image?
How magnified the image is
What are the 4 basic types of tissues?
Epithelial
Connective tissue
Muscle tissue
Nervous tissue
What are different classifications of epithelial tissue?
Columnar
Cuboidal
Squamous
What is epithelial tissue?
Tissue on the surface
What is connective tissue?
Space filling tissue
What are the functions of muscle tissue?
Contractions, movement
What are the functions of nervous tissue?
Integrates and coordinates
What is a tissue?
Group of cells that work together and perform the same function
What is a tissue formed from?
Cells and extracellular substance
What is an organ formed from?
Two or more types of tissues
What are the layers of the muscularis externa?
Inner circular muscle
Outer longitudinal muscle
What is the classification of the epithelium in th eoesophagus?
Stratified squamous non-keritinised epithelium
What kind of muscle is the upper 1/3 of the muscular layer of the oesophagus?
Skeletal muscle
What kinds of muscle is the middle 1/3 of the muscular layer of the oesophagus?
Smooth muscle and skeletal muscle
What kind of muscle of the lower 1/3 of the muscular layer of the oesophagus?
smooth muscle
What do parietal cells secrete?
(stain pink) – secrete HCl
What do chief cells secrete?
at base of the gland – secrete pepsinogen
What is the classification of the epithelium in the stomach?
Simple columnar epithelium
In what layer are the gastric glands in the stomach found?
Gastric glands in mucosa (above muscularis mucosae)
What is unique about the muscularis externa of the stomach?
3 layers of muscles in m.externa (if you can see this layer in the micrograph)
What is found in the mucosa of the small intestine?
Lymphoid aggregations in mucosa - Peyer’s patches
What are crypts of Leiberkuhn?
The crypts of Lieberkuhn (often referred to simply as crypts) are similar to the gastric pits in the stomach. The crypts contain stem cells that can differentiate to produce a number of different cell types, including enterocytes
Where are Brunner’s glands found?
duodenum in submucosa
In what part of the GI tract are peyer’s patches found?
ileum
Where in the GI tract do villi first appear?
They are most prevalent at the beginning of the small intestine and diminish in number toward the end of the tract.
What are Paneth cells?
Paneth cells are secretory cells located in the crypts of Lieberkühn, adjacent to the intestinal stem cells. They produce antimicrobial peptides and proteins and other components that are important in host defense and immunity.
What does the large intestine contain histologically?
Thick mucosa, crypts, mucous secreting cells. No villi.
What are some glands of the GI tract?
Salivary glands (in head/neck block)
Pancreas
Liver (very elaborate gland!)
What is the secretory component of exocrine glands?
Secretory (acinar component) – roundish structure with columnar cells and nuclei at the base
What are the 3 major pairs of salivary glands?
Salivary glands (in head/neck block)
Pancreas
Liver (very elaborate gland!)
what are the histological parts of the pancreas?
1 – Islet of Langerhans – endocrine part – no acini
2 – exocrine part – pancreatic acini
3 – pancreatic duct ( for exocrine part)
