Upper GI Flashcards
What are the four histological layers of the GI tract?
Mucosa
Submucosa
Muscularis externa
Serosa
What type of epithelium are the proximal and distal ends of the GI tract?
Stratified squamous, nonkeratinized
What type of epithelium is the majority of the GI tract?
Simple columnar
What are the two nerve plexi of the GI system?
Submucosal (Meissner’s)
Myenteric (Auerbach’s)
What is the function of the submucosal (Meissner’s) plexus? Parasympathetic or sympathetic innervation?
Regulate the activity of the muscularis mucosae and secretion of glands/blood flow
Parasympathetic
What is the function of the Myenteric (Auerbach’s) plexus? Parasympathetic or sympathetic innervation?
Regulates the activity of the muscularis externa
What is the Z-line in the distal esophagus?
Where stratified squamous epithelium meets stratified columnar (esophagus to cardiac region of the stomach, just distal to the esophageal sphincter)
What is the outermost layer of the mucosae?
Muscularis mucosae
Where are lymphatics found in the GI Tract layers?
Submucosa
What are the layers of the GI tract?
Mucosa
Submucosa
Muscularis externa (propria)
What is the outermost layer of the GI tract? What is the exception to this?
Serosa
Esophagus has an outer coat of epithelium, not a serosa
Where are glands found in the GI tract? What are the two exceptions to this?
Submucosa
What does the myenteric plexus lie between?
Internal circular and external longitudinal muscularis layers
What is Barrett’s esophagus?
Change of the distal esophagus from stratified squamous to simple columnar with goblet cells. This is precancerous (adenocarcinoma)
What is the stain that is used to identify goblet cells? What is this staining?
Alcian blue stains the acidic mucosubstances secreted by the goblet cells
What third of the esophagus is most likely to harbor an adenocarcinoma?
distal third
What third of the esophagus is most likely to harbor a squamous cell carcinoma?
Middle third
How do you determine the staging of esophageal stratified squamous cell carcinoma?
How far the squamous cells infiltrate the esophagus
Who is particularly at risk of squamous cell carcinoma?
AA
EtOH abuse
Men
What type of esophageal cancer would most likely cause hoarseness: SCC or adenocarcinoma? Why?
SCC–can penetrate the wall of the esophagus, and hit the recurrent laryngeal nerve (from CN X)