Stomach Flashcards
where does the stomach extend between?
T7-L3
where is the stomach located between?
oesophagus and duodenum
what is the anterior and posterior surfaces of the stomach covered in?
smoothly rounded with a peritoneum covering
what are the 4 regions of the stomach?
cardia, fundus, body, pylorus
what is the cardia?
surrounds the superior opening of the stomach
what is the fundus?
the rounded portion superior to and left of the cardia
what is the body?
the large central portion inferior to the fundus
what is the pylorus of the stomach?
connects the stomach to the duodenum
what are the medial and lateral borders of the stomach known as? why?
medial & lateral borders of the stomach are curved
known as the lesser and greater curvatures
what does the greater curvature of the stomach form?
long convex lateral border of the stomach
where does the greater curvature of the stomach arise from?
the cardiac orifice
describe the greater curvature of the stomach
cardiac orifice, arches backwards and passes inferiorly to the left
what happens to the greater curvature of the stomach as it continues medially? what does it reach?
curves to the right as it continues medially to reach the pyloric antrum
which arteries supply the greater curvature of the stomach?
short gastric arteries
right & left gastro-omental arteries
what does the lesser curvature of the stomach form?
forms the shorter concave medial surface of the stomach
what is the angular incisure?
the most inferior part of the lesser curvature
what does the angular incisure indicate?
the junction of the body and pyloric region
what does the lesser curvature give attachment to?
hepatogastric ligament
which artery supplies the lesser curvature?
left gastric artery and right gastric branch of the hepatic artery
where does the stomach lie in a supine position?
lies in the right and left upper quadrants or epigastric, umbilical, left hypochondrium and flank regions
where does the stomach move in an erect position?
moves inferiorly
what happens to the internal surface (mucosa) of the stomach when it is empty?
the mucosa lies in folds called rugae
where do rugae (folds) become most prominent in the stomach?
toward the pyloric part and greater curvature
what happens to the rugae during swallowing?
the rugae can form a temporary groove along the lesser curvature
what is the temporary groove along the lesser curvature called?
gastric canal
what is the function of the gastric canal?
masticated food and fluid drain along the canal to the pyloric canal when the stomach is empty
how many sphincters are there in the stomach and where are they located?
2 sphincters of the stomach, one at each end
what is the function of the sphincters of the stomach?
function to control what enters and exists the stomach and when
where is the inferior oesophageal sphincter?
the sphincter between the oesophagus and the stomach
where is the superior oesophageal sphincter located?
in the pharynx
where is the inferior oesophageal sphincter located anatomically?
to the left of the T11 vertebra
how is the inferior oesophageal sphincter marked histologically?
marked by an abrupt change from oesophageal to gastric mucosa
what is located immediately superior to the inferior oesophageal sphincter?
oesophageal hiatus
what is the oesophageal hiatus?
a hole in the diaphragm through which the oesophagus travels
what is the inferior oesophageal sphincter called? why?
physiological (or functional) sphincter
why is the inferior oesophageal sphincter called a physiological sphincter?
it does not have any specific sphincteric muscle, instead, a number of extrinsic forces act
what happens at the oesophageal hiatus?
the right crus exerts pressure on the oesophageal wall
in the normal (non-eating) state, how is the lumen of the oesophagus like?
collapsed
how does the oesophagus enter the stomach?
at an angle
why does the oesophagus enter the stomach at an angle?
when the stomach is full, this closes off entry to the stomach
where is the pyloric sphincter found?
between the pylorus and the duodenum
what does the pyloric sphincter control?
the exit of chyme (food and gastric acid mixture)
what type of sphincter is the pyloric sphincter?
an anatomical sphincter
why is the pyloric sphincter a type of anatomical sphincter?
it contains smooth muscle
what is the function of the smooth muscle in the pyloric sphincter?
thickens to control the discharge of stomach contents through the orifice
how does emptying of stomach occur?
intermittently when intragastric pressure overcomes the resistance of the pylorus
how does the pylorus normally contract? why?
pylorus contracts tonically so that the orifice is small and food can stay in the stomach for a suitable period
what is the function of gastric peristalsis?
gastric peristalsis pushes the chyme through the pyloric canal into the duodenum for further digestion
what are organs within the abdominal cavity covered with?
double layered membrane called peritoneum
what is the function of the peritoneum?
supports viscera and attaches them to the abdominal wall
what is the greater and lesser omenta?
2 structures that consist of peritoneum folded over itself (2 layers of peritoneum, or 4 membrane layers)
