Stomach Week 5 FINISHED Flashcards
What is the stomach? Where is it found?
Expanded part of the digestive system
Found between the oesophagus and the small intestine
What does the size and position of the stomach depend on?
The shape and position however varies between people
Also varies within the individual because of the movement of the diaphragm with respiration
- the stomach’s contents
- the position of the person eg lying or standing
What is the function of the stomach?
- Food blender
- Reservoir
- Secretes gastric juices which gradually converts a mass of food into a liquid mixture = chyme (juice)
- Chyme – semi fluid mixture, creamy material, homogenous (results from the gastric digestion of food)
How much food can the stomach hold?
2-3 litres
What are the 4 parts of the stomach?
Cardia, fundus, body, pyloric region
What are the 2 curvatures of the stomach?
Lesser and greater
Where is the cardia of the stomach?
- part surrounding the cardial orifice (orifice between the distal oesophagus and stomach)
What is the fundus of the stomach? Where is it found? What part of the diaphragm does it relate to? What height does it reach?
= Base / bottom
Dilated superior region
Found above the horizontal plane of the cardial orifice
Relates to the left dome of the diaphragm
Usually reaches the 5th intercostal space (same maximum height as the Lt dome of the diaphragm)
What is found between the fundus and the oesophagus?
The cardial notch is found between the fundus and the oesophagus
Where is the body of the stomach?
Body - region between the fundus and the pyloric antrum
What is the pyloric part of the stomach? What does pylorus refer to?
Funnel part of the stomach
Pylorus - refers to the sphincteric region
What is the widest part of the pyloric region called?
The widest part is called the pyloric antrum (antrum = cave, cavity, chamber)
What is the narrowest part of the pyloric region?
This leads into the narrowest part called the pyloric canal
What is the pyloric sphincter? What does it do?
A region of the pyloric region thickened to form the pyloric sphincter
= gate keeper
The sphincter controls the movement of stomach contents through the pyloric orifice to the duodenum
What is the lesser curve of the stomach? What is 2/3rds along the border of the lesser curvature?
- The shorter concave border of the stomach
- 2/3 rds along the border find a sharp indentation called the angular notch
What is the greater curve of the stomach?
The longer, convex border of the stomach
What does the angular notch of the stomach indicate?
Indicates the junction between the body of the stomach and the pyloric region
Describe the coverage of the stomach by peritoneum
Most of the stomach is covered by peritoneum
2 layers of the lesser omentum extend around the stomach and leave its greater curvature as the greater omentum
What is anterior to the stomach?
- diaphragm
- Lt lobe of the liver
- anterior abdominal wall
What is posterior to the stomach?
- omental bursa (lesser peritoneal sac/ cavity)
- pancreas
What is the arterial supply to the stomach?
Rich supply
Gastric arteries arise from the celiac trunk and its branches
Lt gastric artery: arises directly off the celiac trunk, passes in the lesser omentum
It then courses along the lesser curvature and anastomoses with the Rt gastric artery
Rt gastric artery: arises from the hepatic artery
It also runs along the lesser curvature of the stomach and anastomoses with the Lt gastric artery
Lt gastro-omental artery: arises from the Splenic artery
Runs along the greater curvature of the stomach
Rt gastro-omental artery: is a terminal branch of the gastroduodenal artery
Runs along the greater curvature of the stomach
Anastomoses with the Lt gastro-omental artery
Short gastric arteries (4-5): which arise from the distal end of the splenic artery
Supply the fundus of the stomach
What is the venous drainage of the stomach?
Follow the arteries in position and course
Rt and Lt gastric veins drain into the portal vein
Short gastric veins and the Lt gastro-omental vein drain into the splenic vein
Rt gastro-omental vein drains into the SMV
SMV + splenic vein = portal vein (behind the junction of the neck and the head of the pancreas)
What is the nerve supply to the stomach?
Parasympathetics
- Vagus nerve
Sympathetics
- T6- T9 through the celiac plexus via the greater splanchnic nerves
What are the 3 layers of muscle of the stomach from innermost to outermost?
Three layers of mm
- outermost - longitudinal
- middle - circular
- innermost - oblique
What is the stomach lined with?
What happens to the stomach mucosa when the stomach contracts?
Lined with gastric mucosa
When the stomach contracts the mucosa is thrown into longitudinal folds/ ridges called gastric folds or rugae
What does rugae mean?
Ridge
What epithelium lines the stomach?
Lining epithelium mainly consists of a single layer of mucous secreting columnar cells
