Oesophagus and Stomach Flashcards
At what levels does the oesophagus start and end?
C5
T10
What is the organisation of the epithelial layer in the oesophagus?
Stratified squamous
What type of epithelium does the oesophagus have?
Non-keratnising
How many sphincters does the oesophagus have?
2 - Upper/lower oesophageal sphincter
What triggeres the opening of the oesophageal sphincter?
Swallowing
What type of muscle are the oesophageal sphincters made of?
Upper: Skeletal
Lower: Smooth
What happens if you food cannot pass down the oesophagus?
Signal to brain
Initiates second peristaltic wave
What is the organisation of epithelial cells in the stomach?
Simple columnar
to facilitate absorption
What muscle prevents reflux from the lower oesophageal sphincter?
Diaphragm
What are the gastric folds in the stomach called?
Rugae
What is the purpose of the gastric folds?
When stomach is empty it can get smaller
When full, allows stomach to get larger
What is the top of the stomach called?
Fundus
What is region of the stomach at the entry?
Cardiac
What is the main section of the stomach called?
Body
What is released in the Cardiac region and Pyloric canal?
Mucus only
What is secreted in the Body and fundus?
Mucus, HCL, Pepsinogen
How much acid does the stomach produce a day?
2L
What does mucus contain in the stomach?
HCO3- trapped in mucus gel to neutralise acid to protect cells
What are the two types of stomach contractions, what do they do?
Peristalsis 20%
- To move food down further into system
- Triggered by vagus nerve
Segmentation 80%
- Weaker, mixes contents
- Fluid chyme moved towards pyloric sphincter
- Solid chyme moved towards fundus
What is the cell types in the stomach that secretes proteins (pepsinogen)?
Chief cell
What is present in the chief cell?
Lots of RER
Many golgi
Mass of apical granules for secretion
What cell in the stomach produces acid?
Parietal cells
What cell in the stomach produces acid?
Parietal cells
What two structures are (specially) present in parietal cells?
Cytoplasmic Tubulovesicles -
Internal Canaliculi
What converts Pepsinogen into active Pepsin?
HCl
What does the pyloric antrum produce?
Gastrin
What is Gastrin?
Endocrine hormone that travels to body of stomach!!!!!!!!!
What are the three phases of Gastric secretion?
Cephalic
Gastric
Intestinal
What causes the cephalic phase of secretion?
Thought, sight, smell and taste of food causes signal to be sent from vagus nerve to release ACh to Parietal cells
What triggers the gastric phase of secretion?
Stretch and chemo receptors
What is food that has passed through the stomach called?
Chyme
What triggers the Intestinal phase of stomach secretion?
pH < 2 or lipids in intestine
What happens if the chyme entering the intestine has a high protein concentration?
Intestinal phase causes Antrum to secrete more gastrin to try harder to break down proteins in the food that remains in the stomach
What are the four sections of the Gut wall?
Mucosa
Submucosa
Muscularis
Serosa/Adventitia
What cells does the mucosa contain?
Epithelial cells
Lamina propria
Muscularis mucosae
What does the submucosa contain?
Connective tissue
W/nerve plexus
What is the middle oesophagus comprised of?
Both skeletal and smooth muscle (neither voluntarily controlled)
What is the last section of the stomach?
Pyloric canal
What section of the stomach secretes Gastrin, and where is it found?
Pyloric antrum, just before Pyloric canal
