Upper GI Flashcards
esophagus journey to stomach
Starts at cricoid cartilage
Runs anterior to the vertebrae down through the posterior mediastinum beside descending aorta
passing through esophageal hiatus of diaphragm
into stomach
anatomical markers on esophgus frrom incisor (4)
- Cricopharyngeal sphincter (15cm)
- Arch of aorta (22cm)
- Left main bronchus (27cm)
- Esophageal junction (OG) (40cm)
Normal constrictions of esopgus
cricoid cartilage
aortic arch
diaphram
importance of esophageal constrictions (4)
- Swallowed objects are more likely to get stuck in these areas
- Corrosive fluids swallowed pass slower at these areas than others and can thus cause more damage that at other points in the esophagus
- Difficult to pass surgical instruments through these areas for investigations or interventions
- Food may become lodged in the piriform fossae (two channels on either side of the epiglottis which normally allow liquids into the esophagus)
esophgeal layers
mucosa
submucosa
muscularis externa
adventitia
blood supply of esophagus (3)
- Inferior Thyroid Artery
- Aortic Esophageal Branches
- Left Gastric Esophageal Branches
venous drainage of esophagus
inferior thyroid vein/ aortic branches drain to left gastric vein then hepatic portal system
rest drains through azygous/ brachiocephallic to systemic circulation
portosystemic anastamosis
lumen epithelium of esophagus
non kertitinzed stratified squamous epithleium
what do parietal cells do
HCL and intrinsic factor
cheif cells
pepsinogen, gastric lipase and renin
g cell
gastrin
what does gastrin do
stimulate release of HCL and pepsinogen, increase gastric motility and relaxes pyloric sphincter
diagnosis of barretts
- Endoscopy (OGD)
- Biopsy to confirm metaplasia
- Endoscopic Grading system (prague critera)- measuring length of barretts
management of barretts
- PPI
- Surveillance
- Anti-reflux surgery (if not controlled medically)
- Resection
- Ablation
Normal function of the lower esophageal sphincter (LES)
- Food is transported from the mouth to the stomach by peristaltic contractions of the esophagus muscle
- The LES relaxed as you swallow and this allows food to enter the stomach
- LES contracts and closes to prevent reflux into the esophagus
Multiple mechanisms in place to prevent stomach contents from entering the esophagus:
- LES which only opens during swallowing
- Oblique angle of abdominal esophagus which acts as a valve
- Rosette of mucosal folds from the gastric mucosa at the gastro-esophageal junction which acts like a plug
- Muscle of diaphragm constrict around esophagus to prevent backflow
esopheal offenses
- Gastric secretion
2. Pyloric competence
Protective factors that prevent peptic ulcers:
- Bicarbonate- buffers acid
- Prostaglandins- gets rid of pathogens
- Mucus production- creates a layer between epithelium and acid
- Blood flow to mucosa
Risk factors for peptic ulcers:
- H-pylori (pan gastritis- reduces acid secretion/ pylorus)
- Gastric acid
- Pepsin
- NSAIDs
- Genetics
- Diet
- Smoking
