Anatomy of Esophagus & stomach Dr. Mohammed Abuelnor

Objectives: Describe the anatomy of the esophagus; extent, length, parts, structures, relations, blood & nerve supply and lymphatic. Describe the anatomy of the stomach; location, shape, parts, relations, blood & nerve supply and lymphatic. اسم ورقم المقرر – Course Name and No. 4/25/2019

Esophagus Esophagus is a muscular tube about 25 cm long It extends from pharynx to the stomach It begins at the level of cricoid cartilage in the neck passes behind the trachea It passes down in the thorax through mediastinum It enters the abdominal cavity by piercing diaphragm at the level of 10th thoracic vertebra It enters the right side of the stomach 4/25/2019

Relations in the Neck Anteriorly: Trachea, recurrent laryngeal nerve Posteriorly: Prevertebral muscles, vertebral column Laterally: Thyroid gland, carotid sheath, carotid artery. اسم ورقم المقرر – Course Name and No. 4/25/2019

Relations in the Thorax & Abdomen Anteriorly: Trachea, and the heart Posteriorly: vertebral column, descending thoracic aorta Right : Mediastinal pleura, azygos vein Left : aortic arch, left mediastinal pleura Left and right vagi lie on its anterior and posterior surfaces, respectively

Blood Supply, Nerve Supply, Lymph drainage Inferior thyroid artery, descending thoracic aorta, left gastric artery Venous Drainage: inferior thyroid vein, azygos veins, left gastric veins, tributaries of portal vein Recurrent laryngeal nerve, branches from sympathetic trunk, vagal trunks, esophageal plexus, anterior and posterior gastric nerves (vagi) Lymph: Deep cervical lymph nodes, mediastinal nodes, celiac nodes. اسم ورقم المقرر – Course Name and No. 4/25/2019

Stomach Is the dilated portion of the alimentary canal and has three main functions: Stores food Mixes the food with gastric secretions to form a semifluid chyme Controls the rate of delivery of the chyme to the small intestine

Stomach Situated in the upper part of the abdomen Located into the epigastric and umbilical regions Much of it lies under cover of the lower ribs Is “J” shaped and has two openings, the cardiac and pyloric orifices

Stomach Has two curvatures, lesser and greater Has two surfaces, anterior and posterior Is relatively fixed at both ends but is very mobile in between

PARTS 2 Orifices: Cardiac orifice Pyloric orifice 2 Borders: Greater curvature Lesser curvature 2 Surfaces: Anterior surface Posterior surface 3 Parts: Fundus Body Pylorus: The pylorus is formed of : Pyloric antrum Pyloric sphincter PARTS

Pylorus The pyloric antrum extends from the incisura angularis to the pylorus Pylorus is the tubular part of the stomach Has a thick muscular wall called the pyloric sphincter The cavity of the pylorus is the pyloric canal

ANATOMY OF STOMACH Lesser curvature (LC) forms right border (concave medial border) it is connected to the liver by lesser omentum Greater curvature (GC) forms longer convex lateral border of stomach Gastrosplenic omentum extends from upper part of GC to spleen greater omentum extends from lower part of GC to transverse colon

ANTERIOR RELATIONS Anterior abdominal wall. Diaphragm. The liver.

POSTERIOR RELATIONS Left suprarenal gland. Part of left kidney Spleen. Splenic artery. Pancreas. Transverse mesocolon. Transverse colon. Lesser sac. All these structures form the stomach bed.

Mucous Membrane Mucous membrane of the stomach is thick and vascular and is thrown into numerous folds or rugae Mainly longitudinal in direction The folds flatten out when the stomach is distended

ARTERIES 5 arteries: 1- Left gastric artery: It is a branch of celiac artery. Ascends along the lesser curvature. 2- Right gastric artery: From the hepatic artery of celiac. Runs to the left along the lesser curvature.

ARTERIES 3- Short gastric arteries – arise from the splenic artery. Pass in the gastrosplenic ligament. 4-Left gastroepiploic artery: from splenic artery 5- Right gastroepiploic artery: from the gastroduodenal artery of hepatic . Passes to the left along the greater curvature.

VEINS All of them drain into the portal circulation. The right and left gastric veins drain directly in the portal vein. The short gastric veins and the left gastroepiploic vein join the splenic vein. The right gastroepiploic vein drain in the vein. superior mesenteric

LYMPH DRAINAGE The lymph vessels follow the arteries. They first drain to the: Left and right gastric nodes. Left and right gastroepiploic nodes and the Short gastric nodes. all the lymph from the stomach is collected at the celiac nodes.

NERVE SUPPLY Sympathetic fibers are derived from the celiac plexus. Parasympathetic fibers from both vagi. Anterior vagal trunk: Formed from the left vagus Supply the anterior surface of the stomach Gives off a hepatic branch and from it - a branch to the pylorus. Posterior vagal trunk: Formed from the right vagus Supply the posterior surface of the stomach Gives off a large branch to the celiac and the superior mesenteric plexuses.

References: Gray's Anatomy for Students- Second edition. Clinically Oriented Anatomy , Keith L. Moore- Sixth edition. Netter’s Clinical Anatomy, Second edition.