University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

23

Pages:

7
Author:

Mariam A. A.

Stomach Position Between oesophagus and intestine Inferior to oesophagus Superior to intestines Lies in epigastric and umbilical regions Parts of the stomach Cardia Top part Has cardiac sphincter ✓ Prevents food from travelling back up the oesophagus Surrounds the superior opening of the stomach at the level of T11 In supine position the cardiac orifice usually lies posterior to the 6th left costal cartilage In medial plane at level of 11th vertebra Cardia notch is between oesophagus and fundus Fundus Rounded part Superior to and left to the cardia The dilated superior part is related to the left dome of the diaphragm May be dilated by gas, fluid, food, or any combination of these In supine position lies posterior to the left 6th rib in the plane of MCL Has gastric glands: make gastric juice Has parietal cells which secrete HCL Has Chief Cells which secrete pepsinogen Body Between fundus and pyloric antrum • Antrum Closes during digestion of food and opens again to allow the passage of the digested food to the intestines Leads to pyloric canal Has G cells: secrete gastrin Gastrin stimulates parietal cells to secrete HCl Pyloric Canal The inferior terminal segment of the pyloric antrum that ends at the gastroduodenal junction Pyloric Sphincter Small piece of smooth visceral muscle that acts as a valve Regulated the flow of partially digested food from the stomach to the duodenum Stomach curvatures Lesser curvature Forms the shorter concave right boarder of the stomach Contains a small notch called angular incisure. ✓ Poster inferior part of the lesser curvature ✓ Lies to left of the midline ✓ This marks the line of intersection between the body and the pyloric part of the stomach Greater curvature Forms the longer convex left border of the stomach Passes inferiorly to the left from the junction of the 5th intercostal space and MCL, the curves to the right passing deep to the 9th/10th left cartilage as it continues medially to reach the pyloric antrum Starts from cardiac notch that is formed between the oesophageal border and fundus Interior of the stomach Smooth gastric mucosa Reddish brown except in the pyloric part where it is pink • Covered by a continuous mucus layer that protects its surface from the gastric acid that the stomach’s glands secrete The gastric mucosa is organised into the longitude ridges called gastric folds/gastric rugae Most marked towards the pyloric part and along the greater curvature during swallowing a temporary groove (gastric canal) form between the longitudinal gastric folds along the lesser curvature gastric canal forms because if the firm attachment of the gastric mucosa to the muscular layer which does not have an oblique layer at this site the gastric folds dimmish and obliterate as the stomach distended (fills) Muscles of the stomach • longitudinal muscle • circular muscle • oblique muscle • help mechanical digestion of food Blood supply Celiac trunk > Right and left gastric arteries (along lesser curvature) > Right and left gastro-omental arteries (along greater curvature) > Short gastric artery arising from splenic artery Venous drainage • Right and left gastric veins -> hepatic portal vein • Short vein, right and left gastro-omental veins -> superior mesenteric vein Innervation • Parasympathetic: veins • Sympathetic: celiac plexus