Clinically applied GI I Flashcards
from esophagus to rectum the GI tube is composed of how many layers?
4
what type of epithelium makes up the esophagus?
stratified squamous keratinized
the epithelium lies on top of what layer?
basal lamina
the basal lamina lies on what layer?
lamina propria
what are the four layers of the GI tract?
- mucosa
- submucosa
- muscularis externa
- serosa
what is the histological makeup of the mucosal epithelium?
proximal and distal - stratified squamous nonkeratinized
rest of the tract is simplu columnar
in which sections of the GI tract are there glands in the submucosa?
esophagus and duodenum
what layers make up the mucosa?
epithelium, lamina propria, muscularis mucosae
what are the enteric nerve plexuses?
submucosal (meissner’s) and myenteric (auerbach’s)
the submucosal (meissner’s) plexus carries what fibers?
parasympathetic postganglionic and sympathetic postglanglionic fibers
what is the function of the submucosal (meissner’s) plexus?
regulates activity of muscularis mucosae, gland secretion, blood flow
the myenteric (auerbach’s) plexus carries what fibers?
parasympathetic postganglionic neurons and sympathetic postganglionic fibers
what is the function of the myenteric (auerbach’s) plexus?
regulates activity of muscularis externa
what is the z line?
region in esophagus where stratified squamous nonkeratinized epithelium meets stratified columnar
what is barrett’s esophagus?
metaplastic simple columnar epithelium with goblet cells and adenocarcinoma
what is necessary for the diagnosis of barrett’s esophagus? what stain is used and what component does it stain?
- presence of goblet cells
2. alcian blue - stains acidic mucosubstances secreted by goblet cells
what third of the esophagus will harbor an adenocarcinoma?
distal third
what type of cancer would most likely cause hoarseness?
squamous cell carcinoma
where are the four esophageal constrictions?
- UES
- aortic arch
- primary bronchus
- diaphragm
men are how many times more likely to have stratified squamous cell carcinoma of the esophagus than women?
4x
african americans are how many times more likely to have stratified squamous cell carcinoma of the esophagus?
8x
what muscle constitute the inferior pharyngeal constrictor?
cricopharyngeus and thyropharyngeus
what muscle makes up the superior portion of the inferior constrictor?
thyropharyngeus
what muscle makes up the inferior portion of the inferior constrictor?
cricopharyngeus
what is the clinical relevance of the orientation of the cricopharyngeus and thyropharyngeus?
potential site of weakness between transition in fiber orientation - Killian’s triangle
diverticulum may form
perforation
where does ligation of inferior thyroid artery occur during a thyroidectomy?
distal to esophageal branch
what is the clinical relevance of venous drainage of the esophagus?
portal hypertension with attendant esophageal varices and hematogenous spread of cancer
what is the cause of achalasia?
loss of inhibitory neurons secreting NO and VIP that populate the myenteric plexus
possibly damage to dorsal motor nucleus of vagus nerve or extraesophageal nerve plexus
in which layer of the esophagus does lymph flow most easily? why? what is the clinical significance?
submucosal - longitudinally arrayed channels
easier for metastatic spread
what is the direction of esophageal lymph flow above and below the bifurcation of the trachea?
above - upward
below - downward
what is the incisura angularis?
external landmark to assist in indentifying the antrum from the body of the stomach
where do the majority of peptic ulcers occur?
in the vicinity of the incisura angularis (lesser curvature near gastric notch)
parietal cells are influenced by what other cell type in the stomach?
gastrin producing cells
what is zollinger ellison sydrome? where are these tumors usually located?
- gastrin producing tumor
2. gastrinoma triangle
what are the borders of the gastrinoma triangle? what is within in?
- junction of cystic duct and common hepatic duct
- junction of neck and body of pancreas
- junction of 2nd and 3rd parts of duodenum
pancreas, duodenum
what are the target cells of a gastrinoma?
parietal cells
what is the physical manifestation of gastrinomas in zollinger ellison syndrome?
prominent rugae due to increased parietal cell mass
what are the 6 primary arterial feeders to the stomach?
- right gastric
- left gastric
- right gastro-omental
- left gastro-omental
- gastroduodenal
- splenic
what should be considered when ligating gastric arteries?
anatomical variation - left hepatic artery arising from left gastric
each vagal trunk gives rise to what nerve innervating the stomach?
left and right gastric nerves
what are the nerves of Laterjet?
anterior and posterior gastric nerves
which nerves are preserved in surgery for refractory PUD?
crows feet nerves supplying pylorus
what is the reason for vagotomy of the stomach? what nerves are resected?
denervation regions containing acid secreting parietal cells
how may gastric cancer progress to pancreatic duct obstruction?
lymph drainage along greater curvature into those at head of pancreas
or, mass effect of tumor growing into pancreas
what are the four signature histologic changes of celiac sprue?
arrayed enterocytes
villus atrophy
crypt hyperplasia
inflammation of lamina propria
