esophagus stomach-dr.gosai

ESOPHAGUS AND

STOMACH

Dr.B.B.Gosai

Learning Objectives:

At the end of this lecture student should be able to: Explain anatomy of lower end of esophagus Explain clinical aspect of esophagus like

esophageal constrictions and Porto-systemic anastomosis at lower end of esophagus.

Explain anatomy of stomach with focus on shape, divisions, relations, interior, structure, blood supply, nerve supply and lymphatic drainage.

Explain applied aspect of stomach like gastric ulcer, gastric carcinoma, gastric pain and gastroscopy.

Abdominal Part of Esophagus

Esophagus enters in the abdomen through esophageal opening of diaphragm at T10 vertebral level.

It is related to:Anteriorly : Left lobe

of liver.Posteriorly: Left crus

of diaphragm.

Blood supply and Nerve supply of Abdominal Part of Esophagus

Blood supply:Arterial supply: Left

gastric artery from Coeliac trunk.

Venous drainage: Left gastric vein tributary of Portal vein

Lymphatic drainage: Left gastric and coeliac lymph nodes

Nerve Supply: Parasympathetic:

Vagus nervesSympathetic:

Thoracic sympathetic chain

Clinical Aspect of Esophagus

Esophageal Constrictions

Esophagus has three constrictions:1.At its upper end, where it joins the Pharynx.2.Near its middle, where it is crossed by the

arch of aorta and left main bronchus.3.Near its lower end, where it pierces the

diaphragm.The approximate distances:

From the incisor teeth to these constrictions are 6,10 and 16 inches ( 15, 25 and 41 cms) respectively.

From the external nares to these constrictions are 7.2, 11.2 and 17.2 inches ( 18, 28 and 44 cms) respectively.

Porto-systemic Venous Anastomosis

The lower end of the esophagus is an important site of Porto-systemic anastomosis between the esophageal tributaries of the Azygos vein (Systemic) and the left gastric vein (Portal).

Importance:In case of postal obstruction in cirrhosis of liver,

Portal hypertension occurs. It results in dilatation of this anastomosis and forms esophageal varices.

These varicose veins (varices) may rupture and cause severe bleeding in the stomach and vomiting of blood known as Hematemesis.

Esophageal varices

Achalasia of the cardia

It is failure of the function of gastroesophageal junction.

Cause unknown but associated with degeneration of parasympathetic plexus in the wall of esophagus.

It leas to dysphagia (difficulty in swallowing and regurgitation.

Later on it leads to distal narrowing and proximal dilatation of esophagus.

STOMACH

Position and Shape

Stomach is dilated part of GIT responsible for storage and mixing of food.

Position: Occupy Left hypochondrium, epigastrium and umbilical regions.

Shape: In tall and thin persons: J-Shaped (Elongated

vertically.In short obese persons: Steer-horn shape

(High and transversely placed)

Position and Shape of Stomach

Features of Stomach

Features of stomach

Ends (Openings):Cardiac End (Opening): Upper end at the junction with the

esophagus.Pyloric End (Opening): Lower end at the junction with the

first part of Duodenum.Borders (Curvatures):Lesser Curvature (Right Border): Extends from right side

of cardiac end to pyloric end. It is concave. Its maximum concavity is known as Angular notch (Incisura angularis). It is attached to liver by lesser omentum.

Greater Curvature (Left Border): Extends from Left side of cardiac end, follow fundus of stomach to pyloric end. It is convex. It is attached to spleen by gastrosplenic ligament in upper part and to transverse colon by greater omentum in the rest of the part.

Features of stomach

Surfaces:

Anterior surface: Between lesser and greater curvature facing anteriorly.

Posterior surface: Between lesser and greater curvature facing posteriorly.

Relations of Stomach

Anterior Surface: covered by peritoneum of greater sac.

Related to:Liver ( left lobe and quadrate lobe)Spleen Anterior abdominal wallDiaphragm which separates stomach from

left pleura, left lung an lower ribs.

Anterior Relations of Stomach

Relations of Stomach

Posterior Surface: covered by peritoneum of lesser sac except near cardiac end.

Structures related to posterior surface also known as Stomach bed and separated by cavity of lesser sac)

Structures forming stomach bed (Posterior relations):Left crus of diaphragmAbdominal aortaLeft inferior phrenic arteryCoeliac trunk and splenic arteryBody of pancreasLeft kidney and left suprarenal glandTransverse colon and transverse mesocolonSpleen (separated by cavity of greater sac)

Posterior Relation of Stomach (Stomach Bed)

Divisions of stomach

Stomach is divided into two portions by line extending from angular notch of lesser curvature to the bulge on the greater curvature.

Two portions are: 1. Cardiac portion 2. Pyloric portion Cardiac portion is subdivided in to two parts by transverse line

passing through cardiac end. The two parts are:

The fundus: lies above the transverse line and dome shaped. The body: between transverse line and line from angular notch.

Pyloric portion is subdivided in to two parts by constriction. The two parts are:

The pyloric antrum: between line from angular notch to constriction.

The pyloric canal (pylorus): Terminal part. 1 inch long. In the wall contains circular muscle fibers which form pyloric sphincter.

Structure of Stomach

Mucous membrane: thick, vascular ad thrown in to folds known as Rugae. Space at the lesser curvature between prominent longitudinal fold is known as gastric canal.

Muscular wall: Formed by three layers:Longitudinal: superficial layerCircular layer: Middle layer. At pylorus forms

pyloric sphincter.Oblique: Innermost layer.

Arterial Supply of Stomach

The stomach is a part of foregut. Hence it is supplied by branches of Coeliac artery.

It is supplied by five arteries:1. Left gastric artery: branch of coeliac trunk. Runs

along upper part of lesser curvature and supplies lower part of esophagus and upper right part of stomach.

2. Right gastric artery: branch of hepatic artery (which is branch of Coeliac artery ) near upper border of pylorus. Runs near the lower part of lesser curvature and supplies lower right part of stomach.

Arterial Supply of Stomach

Arterial Supply of Stomach

3. Short gastric arteries: branches of splenic artery (which is branch of Coeliac artery) at the hilum of spleen . Runs in gastrosplenic ligament and supplies fundus of stomach.

4. Left gastroepiploic artery: branch of splenic artery (which is branch of Coeliac artery ) near hilum of spleen. Runs in gastrospleninc ligament and supplies stomach along greater curvature.

5. Right gastroepiploic artery: branch fomr the gastroduodenal beanch of hepatic artery (Which is branch from coeliac artery). Passes along greater curvature and supplies lower part of stomach along the greater curvature.

Venous drainage of Stomach

Venous drainage of stomach

There are 5 veins corresponding to arteries.All drain into portal system as follows:Left and right gastric veins into portal vein.Short gastric and left gastroepiploic vein into

splenic vein.Right gastroepiploic vein into superior

mesenteric vein.

Lymphatic Drainage of Stomach

Lymphatic drainage of stomach

Lymph vessels follow the arteries.They terminate into right and left gastric and

right and left gastroepiploic lymph nodes.Efferents from these nodes drain into coeliac

lymph nodes around the root if coeliac artery on posterior abdominal wall.

Nerve supply of stomach

Sympathetic nerve supply:From coeliac plexus (Formed by greater

splanchnic nerve of thoracic sympathetic chain).

Afferent carry pain sensation.Efferent are motor to blood vessels and

pyloric sphincter.

Nerve supply of Stomach

Nerve Supply of Stomach

Nerve supply of stomach

Parasympathetic nerve supply from vagus nerves:Anterior vagal (gastric)trunk (formed by left vagus):

enter abdomen in front of esophagus. Supply anterior surface of stomach and liver and pylorus.

Posterior vagal (gastric) trunk (formed by right vagus) enter abdomen behind esophagus. Supply posterior surface of stomach, pancreas, intestine upto right 2/3 rd of transverse colon.

Afferent related to gastric reflex.Efferent is secretomotor to glands, motor to muscles

wall and inhibitory to pyloric sphincter..

Clinical Aspect of stomach

Gastric ulcer: Most common site at Antrum close to lesser curvature.

Ulcer on posterior wall may perforate into the lesser sac and becomes adherent to the pancreas. Erosion of pancreas cause referred pain on back.

Erosion of splenic artery leads to hemorrahge.Perforation of ulcer from anterior wall leads to

leakage of contents of stomach in greater sac and cause peritonitis. It may adhere to liver.

Gastric Ulcer: Erosion of mucosaGastric Ulcer: Erosion of mucosa

Gastric Carcinoma: Abnormal growth of the mucosaGastric Carcinoma: Abnormal growth of the mucosa

Clinical Aspect of stomach

Clinical Aspect of stomach

Gastric carcinoma: Common at the greater curvature of stomach.

Gastric pain: Caused by stretching of wall (distension) or spasmodic contraction. Carried by sympathetic nerves via greater splanchnic nerves to T6-T9 spinal segments. It is referred to epigastrium.

Gastroscopy: direct visualization of stomach by flexible fibroptic instrument (Endoscope). It also used to take mucosal biopsy.

Nasogastric intubation in patients with severe debilitating illnesses..

Gastroscopy

References

Clinical Anatomy by Richard Snell (8th Edition)

Gray’s Anatomy (40th Edition)

…..Thanks…..