Year III – Unit V (GI & Renal Systems) DEMO – III Stomach & Duodenum Ali Jasim Alhashli Year III – Unit V (GI & Renal Systems)

STATION – 1 (Anatomy of The Stomach & Duodenum) The shape of the stomach is dynamic (changing in shape as it functions) & highly variable from person to person. The stomach has four parts & two curvatures. Four Parts of The Stomach Cardia Surrounding the cardial orfice (the trumpet-shaped opening of the esophagus into the stomach) Fundus The dilated superior part – it is related to the left dome of the diaphragm – and it is limited inferiorly by the horizontal plane of the cardial orfice – there is a cardial notch between the sophagus and the fundus. Body It is the major part of the stomach between the fundus and the pyloric antrum. Pyloric part Funnel shaped with two parts: -Pyloric antrum: wide part. -Pyloric canal: narrow part. -The pylorus is the distal sphincteric region (a thickening of the circular layer of smooth muscle, which controls discharge of the stomach contents through the pyloric orfice into the duodenum. Two Curvature of The Stomach Lesser curvature The shorter concave border of the stomach – The angular notch is found 2/3 the distance along the lesser curvature (it is the junction of the body and pyloric part of the stomach. Greater curvature The longer convex border of the stomach.

STATION – 1 (Anatomy of The Stomach & Duodenum) Interior of the stomach: - There are contracted longitudinal gastric folds (rugae). These are most marked toward the pyloric part and along the greater curvature. Vasculature of the stomach Arterial supply •Lesser curvature: left gastric artery (from the celiac trunk) & right gastric artery (from hepatic artery). •Greater curvature: right & left gastro-omental (gastro-epiploic artery) from the celiac trunk. •Fundus & upper body: short & posterior gastric arteries branches from the splenic artery. Venous drainage •Left & right gastric veins will drain into hepatic portal vein. •Short gastric veins & left gastro-omental veins drain into the splenic vein. •Right gastro-omental vein empties into SMV. Lymphatics •Gastric & gastro-omental lymph nodes draining to celiac lymph nodes. Innervation •Parasympathetic: anterior and posterior vagal trunks. •Sympathetic: T6-T9 Relations of the stomach: Anteriorly: diaphragm – left lobe of the liver & anterior abdominal wall. Posteriorly: omental bursa and pancreas.

STATION – 1 (Anatomy of The Stomach & Duodenum)

STATION – 1 (Anatomy of The Stomach & Duodenum)

STATION – 1 (Anatomy of The Stomach & Duodenum) Stomach bed: - From superior to inferior the stomach bed is formed by the left dome of the diaphragm, spleen, left kidney and suprarenal gland, splenic artery, pancreas, transverse mesocolon and colon.

STATION – 1 (Anatomy of The Stomach & Duodenum) - It is the first and shortest (25 cm) part of the small intestine. Also it is the widest and the most fixed part. It begins at the pylorus on the right side and ends at the duodenojejunal junction on the left side. The duodenum has four parts: Four Parts of The Duodenum Superior (first) part Short (5 cm) – horizontal – lies anterolateral to the body of L1 vertebra. Descending (second) part Longer (7-10 cm) – runs infeiorly along the right sides of the L2 & L3 vertebra – curving around the head of the pancreas – lies to the right & parallel to the IVC. The bile duct & main pancreatic duct open it its posteromedial wall via the hepatopancreatic ampulla. Inferior (horizontal or third) part (6-8 cm) – crosses anterior to IVC & aorta – crosses posterior to superior mesenteric vessels – at the level of L3 vertebra. Ascending (fourth) part Short (5 cm) – left to the L3 vertebra – rises to the superior border of the L2 vertebra – left to the aorta – it curves anteriorly to join the jejunum at the duodeno-jejunal junction which is supported by the suspensory muscle of the duodenum. Note: the first 2 cm of the superior part of the duodenum has a mesentery and is mobile. The distal 3 sm of the superior part and the other three parts of the duodenum have no mesentery and are immobile because they are retropreitoneal.

STATION – 1 (Anatomy of The Stomach & Duodenum)

STATION – 1 (Anatomy of The Stomach & Duodenum)

STATION – 1 (Anatomy of The Stomach & Duodenum) Arterial Supply of The Duodenum •Superior pancreatico-duodenal arteries arising from the gasroduodenal artery. These arteries supply the first & second parts of the duodenum. •Inferior pancreatico-duodenal arteries arising from SMA. These arteries supply the third and forth parts of the duodenum. Venous drainage of the duodenum •Through the hepatic portal vein. Lymphatics •Anterior lymphatic vessels will drain into the pancreaticoduodenal lymph nodes which in turn will drain into the pyloric lymph nodes. •Posterior lymphatic vessels will drain into the superior mesenteric lymph nodes. Note: eventually, all of them will drain into the celiac lymph nodes. Innervation •Parasympathetic: from vagus nerve. •Sympathetic: from the greater & lesser splanchnic nerves by the way of the celiac and superior mesenteric plexus.

STATION – 2 (Surface Anatomy of The Stomach & Duodenum) Cardia: at the level of T10 vertebra – left 7th costal cartilage – 2.5 cm away from the left side of the sternum. Pyloric part of the stomach: at the level of L1 vertebra (transpyloric plane). Lesser curvature: it is the convex line joining the two opening of the stomach – it is 1 cm right to the midline. Fundus: it is 1 cm below the apex of the heart (6th costal cartilage). Surface anatomy of the duodenum: First part of the duodenum: at the level of L1 vertebra (right midclavicular line). Second part of the duodenum: from L1-L3 vertebra (at the midpoint between the transpyloric & trantubercle planes). Third part of the duodenum: at the level of L3 vertebra. Fourth part of the duodenum: from L3 to L2 ending toward the left side in duodenojejunal junction. Note: The pancreas is at the level of L1-L3 vertebra (retroperitoneally) and it is embrace by the C-shaped curve of the second part of the duodenum. CA of the pancreas: when removing the head we must take care not to injure superior & inferior pancreaticoduodenal arteries because they are supplying the duodenum.

STATION – 2 (Surface Anatomy of The Stomach & Duodenum)

STATION – 2 (Surface Anatomy of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

STATION – 3 (Histology of The Stomach & Duodenum)

GOOD LUCK!