Lab 2: Histology Flashcards
What are the main layers of the stomach?
Mucosa
Submucosa
Muscularis externa
Adventitia/Serosa
What are the layers of the mucosa layer?
Epithelium
Lamina propria
Muscularis mucosae
The oesophagus transports food from the oral cavity to the stomach. It is lined by ____ epithelium.
Stratified non-keratinised squamous epithelium
The muscularis externa of the oesphagus is made up of which layers of muscle
- The inner circular smooth muscle
- The outer longitudinal smooth muscle
How does the composition of the muscularis externa change between the first 1/3 and the final 2/3 of the oesophagus?
The first 1/3 of the oesophagus features striated, voluntary muscle (skeletal). Not under voluntary control but reflex
While the latter 2/3 is involuntary smooth muscle
Which layer of the wall of the oesphagus is important in driving peristalsis
Muscular externa
What is the function of the muscular mucosae layer in the oesphagus wall
Improves the contact between the stratified sqamous epithelium and the bolus
The sqamous epithelium in the oesphagus is very pink in colour. Why is this?
This is because of the glycogen that is stored in these cells
Mucous glands are located in the _____ layer of the oesphagus
Submucosa layer
Fill in the blanks regarding the layers of the stomach
Chief cells have high levels of which cellular structure and why?
High in ribosomes
This is because they have a high turnover for the protein, pepsinogen
The gastric glands contain mucous cells, chief cells, parietal cells, and enterochromaffin-like (ECL) cells.
What does each of the cell types above secrete?
Mucous cell = mucous
Chief cell = pepsinogen
Parietal cell = HCl and intrinsic factor
ECL cell = histamine.
Where do G-cells secrete gastrin?
Gastrin is secreted into the blood (NOT into the stomach lumen).
What cells does gastrin act upon?
It acts upon parietal cells to increase HCl secretion.
In the haematoxylin and oesin standed section of a stomach, the parietal cells and chief cells can be seen.
Which cell would be stained red and which blue?
Chief cells stain blue bcause they have a high level of rough ER
Describe how the gastric glands vary between the regions of the stomach?
The cardia is high in glands
The pylorus glands are more mucus secreting in function
Describe Barrett’s oesphagus?
- The esophagus is typically characterized as having a stratified squamous epithelium that protects against mechanical damage that can be induced by the peristaltic action of the esophagus on food.
- In patients who have chronic gastro-esophageal reflux disease (GERD), the lower portion of the esophagus is exposed to large amounts of stomach acid and undergoes a metaplastic change. This metaplastic response involves the development of a columnar, secretory epithelium typical of the duodenum and small intestine.
- While this new mucous-producing epithelium is protective, the metaplasia may serve as a precursor to esophageal cancer.
Name this junction?
Gastro-oesphageal junction
