Semester II, Weeks 4-5 (mouth to stomach) Flashcards
What is this slide?
How can you tell?
What is the stain?
Developing Tooth in the bell stage
- the distinct enamel/dentin layer structure in the center of the image
- AZAN stain
What is the blue area of this central structure?
It’s actually made up of two layers… one darker blue to the right and one lighter blue to the left… what are they?
darker blue - predentine - uncalcified dentine matrix produced by odontoblasts
lighter blue - dentine - partially calcified
What is this green highlighted area?
What does it contain?
dental papilla
- contains mesenchyme and small blood vessels
- becomes the dental pulp
There is a layer of cells between the blue central structure and the lighter, spotty pink area to its right.
What are these cells?
odontoblasts
- single layer of columnar cells
What is the thin dark pink layer shaped like a fingernail just left of the blue area?
enamel
What is this circled layer of cells just left of the dark pink layer?
two terms: the kind of cells and the layer
ameloblasts in the inner enamel epithelium
- elongated columnar cells which produce enamel
- AKA enameloblasts or adamantoblasts
What is this layer just left of the enamel-producing cells?
stratum intermedium
What is this darker pink cell layer just inside the green circle?
outer enamel epithelium
- simple cuboidal
What is this area where the outer and inner pink layers meet?
Hertwig’s Rooth Sheath
- meeting of inner and outer enamel epithelium
- no enamel produced here
What is this area marked by the orange arrow?
stellate reticulum
- area inside the “enamel organ” surrounded by the two enamel epithelial layers
- filled with star-shaped epithelial cells
Theoretically, there are small blue processes extending from the odontoblast layer into the blue structure here.
What are they and what are they called?
Tomes’ Fibers
- odontoblast processes extending into the dentine
What is this organ?
How can you tell?
Parotid Gland
- only serous acini
- contains adipocytes within lobules which differentiates it from the pancreas
What are these structures pointed out here?
How can they be differentiated from other similar structures in this organ?
Striated Ducts of the parotid gland
- found within the lobules, unlike the interlobular ducts within the septa between them
- much more visible than the squamous/low cuboidal intercalated ducts because they are tall cuboidal/columnar
What is this structure?
How can you tell?
Intercalated Duct in the parotid gland
- within a lobule, so not interlobular
- low cuboidal cells… much smaller than the nearby striated duct
- organ contains only serous acini so it’s parotid
What is the structure circled in red?
Its location gives away its name… how?
Interlobular Duct of the parotid gland
- found within a CT septum between lobules of the gland
What is this organ?
How can you tell?
This is not the staining used on this specimen in class… what staining is that and why?
Sublingual Gland
- contains both serous and mucus acini but has more mucus acini than the submandibular gland
- we have mucicarmin and hematoxylin stained specimens to show the mucus acini better
What is the structure indicated by the pointer?
interlobular duct of the sublingual gland
What is this organ?
How can you tell?
Submandibular Gland
- mixed sero-mucus gland with predominantly serous acini
What is this structure?
How can you tell?
Striated Duct in the submandibular gland
- organ is mixed seromucus with mostly serous acini
- duct is within a lobule, so it’s striated, not interlobular
What is this organ?
How can you tell?
esophagus
- contains inner circular and outer tongitudinal muscles layers with skeletal muscle interspersed throughout
- epithelium is stratified squamous non-keratinized
What is this layer?
In what organ?
What does it contain?
submucosa of esophagus
- esophageal glands and Meissner’s Plexus
What is this layer?
muscularis mucosae
- longitudinal smooth muscle that makes the folds of the GI tract
What is this layer?
Myenteric Plexus of Auerbach
- neurons and nerve fibers between the layers of the tunica muscularis
What is this layer?
Lamina Propria of the esophagus
- loose CT with lymph follicles
What is this layer called?
What is it called in organs outside the peritoneum?
Serosa
- known as adventitia on extraperitoneal organs
What are the structures indicated by the long arrows?
How can you tell?
esophageal glands proper
- they are mucous glands found in the submucosa of the esophagus
- this can be distinguished by the stratified squamous non-keratinized epithelium to the left of the small arrow at the esophagogastric junction
What are these circled structures?
How can you tell?
If they were found under the other kind of epithelium in this slide what would they be?
Cardiac Glands
- mucus secreting glands in the lamina propria of the cardiac region of the stomach
- if they were found under the stratified squamous non-keratinized epithelium to the right they would be Schaffer’s Glands (AKA cardiac esophageal glands)
What is this organ?
How can you tell?
Stomach (specifically fundus)
- gastric pits are visible on the lumenal (right) side of the slide
What layer does the pointer indicate?
Tela Submucosa of the stomach
- between the epithelium/propria/muscularis mucosae and the tunica muscularis
What are the invaginations indicated by the two arrows?
Gastric Pits
- openings of gastric glands
This is a close-up view of a gastric gland.
What are these lighter staining cells indicated by arrows?
Mucus Neck Cells
- found along the neck and corpus of the gland
What are these larger cells found in a gastric gland called?
Parietal Cells
- round eosinophilic cells with prominent nuclei
- secrete HCl
What is this circled cell here, found in a gastric gland?
How can you tell?
Where in the gland is it found?
What is its function?
Chief Cell
- chief cells are much more basophilic than parietal cells (one of which is seen at the top of the image) and contain zymogen granules
- found in the base of gastric glands
- releases pepsinogen
What is this organ?
How can you tell?
What is the staining?
Stomach (fundus)
- gastric pits
- PAS-Congo-haemotoxylin stain
What is this cell type?
How can you tell?
Parietal Cells (w/ PAS-Congo-H stain)
- eosinophilic cytoplasm
- large round central nucleus
- staining pinkish/orange with congo
What is this organ?
How can you tell?
Pylorus / Gastro-duodenal Junction
- Brunner’s glands are visible in the submucosa of the duodenum on the right side of the image
(none of which are found in the pyloric part to the left)
What is this structure?
How can you tell?
Pyloric Sphincter
- it’s an obvious thickening of the inner circular layer of the tunica muscularis
What are these structures?
Where are they found specifically?
How can you tell?
Mucus glands of the pylorus
- here they are seen at the gastroduodenal junction which is evident because Brunner’s glands and intestinal glands are visible nearby
