Functional and Applied Anatomy of the Stomach Flashcards
What is the stomach?
The expanded part of the GI tract between the oesophagus and duodenum
What is the stomach specialised for?
The accumulation of ingested food
How much food can the adult stomach hold?
2 to 3 litres
What does the adult stomach loook like?
Resembles the letter J, but the size and position of teh stomach varies1
What does the size and position of the stomach vary depending on?
- Body shape
- Degree of distention
- Posture
What are the structural features of the stomach?
- Five recognisable parts
- Greater and lesser curvature
What are the five recognisable parts of the stomach?
- Cardia
- Fundus
- Body
- Antrum
- Pylorus
What are the curvatures of the stomach?
- Greater
- Lesser
Label this diagram
- A - Oesophagus
- B - Cardiac notch of the stomach
- C - Cardia
- D - Fundus
- E - Body
- F - Lesser curvature of the stomach
- G - Greater curvature of the stomach
- H - Pylorus
- I - Antrum
Where do sphincters exist in the stomach?
At the entry and exit parts of the stomach
Where does the oesophagogastric junction lie?
To the left of the T11 vertebra on the horizontal plane that passes through the tip of the xiphoid process
What is meant by the Z-line?
The line where the mucosa abruptly changes from oesophageal to gastric
What happens immediately superior to the Z-line?
The diaphragmatic musculature forming the oesophageal hiatus functions that contracts and relaxes
What is the purpose of the physiological sphincter formed by the diaphragmatic musculature?
Prevents the reflux of stomach contents
What anatomical feature does the diaphragmatic musculature sphincter work with to prevent reflux of the stomach contents?
Cardiac notch
How common is reflux of the gastric contents into the oesophagus?
Common
When can reflux of the gastic contents into the oesophagus be problematic?
If it is frequent and/or clearance of reflux material is deficient
What can happen if reflux of gastric contents is frequent and/or clearance of reflux material is deficient?
‘Heartburn’ and/or inflammation with ulceration may result
What may chronic reflux result in?
Metaplastic changes in the mucosa (Barrett’s oesophagus)
Label this diagram
- A - Diaphragm
- B - Endothoracic fascia
- C - Pleura
- D - Upper limb of phrenoico-oesophageal ligament
- E - Endoabdominal fascia
- F - Cardial notch
- G - Lower limb of phrenico-oesophageal ligament
- H - Cardial orifice of stomach
- I - Oesophagogastric junction (Z-line)
- J - Peritoneum
Where is the pyloric sphincter located?
At the pyloric end of the stomach obviously
What produces the pyloric sphincter?
The circular muscle coat is thickened
What does the pyloric sphincter do?
Controls the discharge of the stomach contents through the pyloric orifice into the duodenum
Label this diagram
- A - Pyloric part of stomach
- B - Pyloric orifice
- C - Duodenum
What happens to the gastric mucosa when empty?
It is thrown into longitudinal folds called rugae, and a gastric canal forms temporarily
Where does the gastric canal form?
Between the gastric folds along the lesser curvature
What is the purpose of the gastric canal?
Allows saliva and other fluids (and small amounts of chewed food) to pass along to the pylorus
What are the histologically distinct zones of the gastric mucosa?
- Cardia
- Fundus and body
- Pyloric
What cells are found in the cardia mucosa?
Neck cells
What do neck cells in the cardia produce?
Mucus
What cells are found in the fundus and body mucosa?
- Neck cells
- Parietal
- Chief
What do neck cells in the fundus and body produce?
Mucus
What do parietal cells in the fundus and body produce?
Acid
What do chief cells in the fundus and body mucosa produce?
Pepsinogen
What cells are found in the pyloric mucosa?
- Neck cells
- G-cells
What do the neck cells in the pyloric mucosa produce?
Mucus
What do G-cells in the pyloric mucosa produce?
Gastrin
Label this diagram
- A - Gastic pit (opening to the gastric gland)
- B - Mucous epithelium
- C - Lymphatic vessel
- D - Lamina propria
- E - Muscularis mucosae
- F - Submucosa
- G - Oblique muscle
- H - Circular muscle
- I - Longitudinal muscle
- J - Serosa
- K - Myenteric plexus
- L - Gastric pit
- M - Gastric gland
- N - Mucous cells
- O - Neck
- P - Parietal cells
- Q - Chief cells
- R - Smooth muscle cel
- S - G cell
Where do peptic ulcers commonly occur?
In the antrum and along the lesser curvature of the stomach
What does perforation of peptic ulcers lead to?
Spillage of gastric contents into the peritoneal cavity
What may be the result of spillage of gastric contents into the peritoneal cavity?
Affects abdominal structures
What abdominal stuctures may be affected by the spilling of gastric contents into the peritoneal cavity?
Pancreas and associated blood vessels lying in close proximity to the stomach
What is the greater omentum?
A prominent, four-layered peritoneal fold that hangs down like an apron from the greater curve of the stomach
What happens to the greater omentum after descending?
It folds back and attaches to the anterior surface of the transverse colon and its mesentery
What is the lesser omentum?
A much smaller, double-layered peritoneal fold that connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver
What does the lesser omentum connect the stomach to?
The portal triad
What is the epiploic foramen (omental foramen)?
An opening
What is the importance of the epiploic foramen?
The greater and lesser sacs communicate through it
Where is the epiploic foramen situated?
Posterior to the free edge of the lesser omentum (hepatoduodenal ligament)
How can the omental foramen be located?
By running a finger along the gall bladder to free the edge of the lesser omentum
How many fingers does the omental foramen usually admit?
Two fingers
Label this diagram
- A - Diaphragm
- B - Falciform ligament
- C - Liver
- D - 7th rib
- E - Porta hepatis
- F - Lesser omentum
- G - Finger is inserted through omental forament into omental bursa
- H - Gallbladder
- I - Costodiaphragmatic (pleural) recess
- J - 10th rib
- K - 11th costal cartilage
- L - Transversus abdominis muscle
- M - Oesophagus
- N - Diaphragm
- O - Stomach
- P - Greater omentum, gastrocolic portion
- Q - Anastomosis between right and left gastro-omental arteries
- R - Transverse colon appearing in an unusal gap in the greater omentum
What does the coeliac trunk originate from?
The abdominal aorta
What does the coeliac trunk give rise to?
The left gastric, splenic, and common hepatic arteries
Label this diagram
- A - Left gastric artery
- B - Celiac trunk
- C - Right and left branches
- D - Cystic artery
- E - Hepatic artery proper
- F - Right gastric artery
- G - Common hepatic artery
- H - Gastroduodenal artery
- I - Supraduodenal artery
- J - Superior pancreaticoduodenal artery
- K - Right gastro-omnetal artery
- L - Abdominal aorta
- M - Left gastro-omental artery
- N - Spleen
- O - Splenic branches
- P - Short gastric arteries
- Q - Splenic artery
- R - Posterior gastric artery
- S - Aortic hiatus
What does the rich arterial blood supply of the stomach arise from?
The celiac trunk and its branches
What is the arterial supply to the lesser curvature of the stomach?
- Left gastric artery
- Right gastric artery
What does the left gastic artery arise from?
Coeliac trunk
What does the right gastric artery arise from?
Coeliac trunk -> Common hepatic
What is the arterial supply to the greater curvature?
- Left gastro-omental
- Right gastro-omental
What does the left gastro-omental artery arise from?
Coeliac trunk -> Splenic
What does the right gastro-omental artery arise from?
Coeliac trunk -> Common hepatic -> Gastroduodenal
What is the arterial supply to the fundus and body of the stomach?
Posterior gastric/small gastric
What is the arterial supply to the fundus and body?
Coeliac trunk -> Splenic
What do the veins of the stomach do?
Parallel the arteries in position and course
What does the left gastric vein follow?
The course of the left gastric artery
What does the left gastrin vein drain into?
The hepatic portal vein
What does the right gastric vein follow?
The course of right gastric artery
What does the right gastric vein drain into?
The hepatic portal vein
What does the short gastric vein follow?
The course of the short gastric artery
What does the short gastric vein drain into?
The splenic vein
What does the splenic vein join?
Superior mesenteric vein
What is formed from the joining of the splenic vein and SMV??
Hepatic portal vein
What does the left gastro-omental vein follow?
The course of the left gastro-omental artery
What does the left gastro-omental vein drain into?
The splenic vein
What does the right gastro-omental vein follow?
The right gastro-omental artery
What does the right gastro-omental vein drain into?
The superior mesenteric vein
Label this diagram
- A - Left gastric vein
- B - Right gastric vein
- C - Portal vein
- D - Prepyloric vein
- E - Pylorus
- F - Pancreaticoduodenal veins
- G - Duodenum
- H - Superior mesenteric vein
- I - Inferior mesenteric vein
- J - Right gastro-omental vein
- K - Splenic vein
- L - Left gastro-omental vein
- M - Middle gastric vein
- N - Short gastric vein
What are the categories of causes of inflammation of the stomach (gastritis)?
- Acute
- Chronic
What can cause acute gastritis?
- NSAIDS
- Alcohol
- Exfoliation of the surface epithelial cells and decreased secretion of protective mucus
What can cause chronic gastritis?
- Infection with the bacteria H. Pylori
- Inflammatory changes in the mucosa result in atrophy and epithelial metaplasia
What may gastric epithelial metaplasia develop into?
Carcinoma
