Stomach Flashcards
Function of the stomach
Accumulation of ingested food
How much food can an adult stomach hold
2-3l
What affects the size and position of the stomach
Body shape
Degree of distension
Posture
What are the 5 parts of the stomach
Cardia - surrounds superior opening
Fundus - rounded portion superior to and left of the cardia
Body - large central portion inferior to the fundus
Antrum - rounded portion inferior to the body and left of the pylorus
Pylorus - connects to duodenum
What is the Z line
Line where the mucosa changes from oesophageal to gastric
Where is the oesophagogastric junction
Left of T11 vertebra
What is the inferior oesophageal sphincter
Diaphragmatic musculature forming the oesophageal hiatus (hole in diaphragm that oesophagus passes through) immediately superior to the Z line
What prevents acid reflux as well as the inferior oesophageal sphincter
Cardiac notch
What occurs as a result of frequent acid reflux
Heartburn
Ulceration
Barrett’s oesophagus
What is the pyloric sphincter
Thickened coat of circular muscle at the pyloric end of the stomach
Function of the pyloric sphincter
Controls discharge of the stomach contents through the pyloric orifice into the duodenum
How does the gastric mucosa exist when the stomach is empty
In longitudinal folds called rugae and a gastric canal temporarily forms between the gastric folds along the lesser curvature
What does the gastric canal allow
Saliva and other fluids to pass along to the pylorus
What cells produce mucus
Neck cells
What cells produce acid
Parietal cells
What cells produce pepsinogen
Chief cells
What cells produce gastrin
G cells
What cells are found in the cardia
Neck cells
What cells are found in the fundus and body
Neck cells
Parietal cells
Chief cells
What cells are found in the pylorus
Neck cells
G cells
Where do peptic ulcers commonly occur
Antrum
Lesser curvature
What does perforation of peptic ulcers lead to
Spillage of gastric contents into the peritoneal cavity
Origin of the coeliac trunk
Abdominal aorta
What arises from the coeliac trunk
Left gastric artery
Splenic artery
Common hepatic artery
Blood supply of lesser curvature
Coeliac trunk -> left gastric
Coeliac trunk -> common hepatic -> right gastric
Blood supply of the greater curvature
Coeliac trunk -> splenic -> left gastro-omental
Coeliac trunk -> common hepatic -> gastroduodenal -> right gastro-omental
Blood supply of the fundus and body
Coeliac trunk -> splenic -> posterior gastric
Coeliac trunk -> splenic -> short gastric
Venous supply of the stomach
Left gastric vein Right gastric vein Short gastric vein Left gastro-omental vein Right gastro-omental vein (All follow course of respective arteries)
What does the left gastric vein drain into
Hepatic portal vein
What does the right gastric vein drain into
Hepatic portal vein
What does the short gastric vein drain into
Splenic vein
What forms the hepatic portal vein
Formed when the splenic vein and superior mesenteric vein join
What does the left gastro-omental vein drain into
Splenic vein
What does the right gastro-omental vein drain into
Superior mesenteric vein
What causes acute gastritis
NSAIDs
Alcohol
What occurs in acute gastritis
Exfoliation of surface epithelial cells and decreased secretion of protective mucus
What causes chronic gastritis
Helicobacter pylori
What occurs in chronic gastritis
Inflammatory changes in the mucosa result in atrophy and epithelial metaplasia
What abdominal regions does the stomach occupy
Epigastric
Umbilical
Where does the greater curvature run from and to
From cardiac orifice to pyloric antrum
What is the junction between the body and pylorus
Angular incision (most inferior part of the lesser curvature)
What extrinsic forces control entry of material into the stomach
At the oesophageal hiatus, the right crus of the diaphragm exerts pressure on the oesophageal wall
In the non eating state, the oesophagus is collapsed
The oesophagus enters the stomach at an angle so when the stomach is full, entry to the stomach is closed off
When does the stomach empty
When intragastric pressure overcomes the resistance of the pylorus (normally contracted)
Parasympathetic innervation
Posterior vagal trunks which are derived from the vagus nerve
Sympathetic innervation
Coeliac plexus (T6-9)
What do the gastric lymphatic vessels drain into
Gastric lymph nodes
Gastro-omental lymph nodes
What do the efferent vessels from the gastric and gastro-omental lymph nodes drain into
Coeliac lymph nodes
Where are the coeliac lymph nodes
Posterior abdominal wall
What is GORD
Gastro-oesophageal reflux disease
A disorder affecting the lower oesophageal sphincter
Main causes of GORD
Dysfunction of the lower oesophageal sphincter
Delayed gastric emptying
Hiatus hernia
What is a hiatus hernia
Part of the stomach protrudes into the chest though oesophageal hiatus in the diaphragm
Types of hiatus hernia
Sliding
Rolling
Describe a sliding hiatus hernia and give the common complication
Lower oesophageal sphincter slides superiorly
Reflux as the diaphragm is no longer reinforcing the sphincter
Describe a rolling hiatus hernia
Lower oesophageal sphincter remains in place but a part of the stomach herniates into the chest next to it
