Oesophagus Flashcards
What is the oesophagus?
A muscular tube that runs from the pharynx to the stomach
What does the oesophagus lie posterior to?
The heart and trachea
What are the 2 sphincters of the oesophagus?
Upper oesophageal sphincter
Lower oesophageal sphincter
What epithelium does the oesophagus have?
Non-keratinising stratified squamous epithelium
Is the epithelium of the oesophagus keratinised or non-keratinised?
Non-keratinised
Where do the submucosal glands lie and what is their function?
In the lamina propria.
They secrete mucus that protects the oesophagus from acidic gastric juices.
What is the thin layer of smooth muscle that supports the mucosa and allows it to move and fold?
The muscularis mucosa
What are the 2 muscular layers of the oesophagus?
Circular inner layer
and
Outer longitudinal layer
What are the 3 muscle types of the oesophagus?
Upper - skeletal
Middle - mixed
Lower - smooth
What occurs at the gastro-oesophageal junction?
A distinct cell change
What is the distinct cell change at the gastro-oesophageal junction?
From stratified squamous (in the oesophagus) to simple columnar (in the stomach)
What are the 2 phases of swallowing?
Oral phase and pharyngeal phase
What are 3 ways in which food moving in the wrong direction is avoided?
- Soft palate raises: to block nasal cavity
- Tongue blocks the oral cavity
- Epiglottis closes: to block the trachea and larynx
What constricts to move the food bolus from the pharynx into the oesophagus?
The pharyngeal constrictor
What occurs to drive the food bolus down the oesophagus?
Peristalsis
