Gastro-intestinal tract
1. Stomach
External features
J shaped muscular bag
Two orifices
th
o Cardiac orifice - Lies behind the left 7 costal cartilage (T11).
Has a physiological sphincter (not anatomical)
o Pyloric orifice -Lies at the level of transpyloric plane (L1).
Its position is indicated by,
A circular groove produced by underlying pyloric sphincter
The prepyloric vein/ vein of Mayo lying in front
Anatomical, physiological sphincter
In epigastric, umbilical and left hypochondrial regions
Widest and most distensible part of GI tract
Fundus-filled with air
Parts of the stomach Cardiac part Body
Pyloric part Pyloric antrum
Pyloric canal
▪Relations –
-Peritoneal,
Ventral mesogastrium (dorsal part) - lesser omentum
Dorsal mesogastrium 1.along the greater curvature- greater omentum
2. near the fundus- gastrosplenic ligament
3. near the cardiac end- gastrophrenic ligament
1
, -Visceral,
Anterior – Anterior abdominal wall
Left costal margin
Diaphragm
Left lobe of liver
Posterior (Stomach bed) –
Pancreas
Transverse colon
Left kidney
Left suprarenal gland
Spleen
Splenic artery
▫Are separated from stomach by the lesser sac
Superior – left dome of diaphragm
Inferior – coils of intestine
Functions
Storage of food
Mechanical grinding and digestion
Prevent reflux
Prevent digestion and damage of its wall
Controlled release of food at pylorus
Absorption (H2O, Ethanol)
Intrinsic factor
Mechanisms to prevent gastroesophageal reflux
Physiological sphincter at the gastroesophageal junction
o Transverse mucosal folds of gastroesophageal junction
o Sphincteric action of right crus of diaphragm
Acute angle of entrance of esophagus into the stomach
The positive intra-abdominal pressure compresses the abdominal part of esophagus.
2
1. Stomach
External features
J shaped muscular bag
Two orifices
th
o Cardiac orifice - Lies behind the left 7 costal cartilage (T11).
Has a physiological sphincter (not anatomical)
o Pyloric orifice -Lies at the level of transpyloric plane (L1).
Its position is indicated by,
A circular groove produced by underlying pyloric sphincter
The prepyloric vein/ vein of Mayo lying in front
Anatomical, physiological sphincter
In epigastric, umbilical and left hypochondrial regions
Widest and most distensible part of GI tract
Fundus-filled with air
Parts of the stomach Cardiac part Body
Pyloric part Pyloric antrum
Pyloric canal
▪Relations –
-Peritoneal,
Ventral mesogastrium (dorsal part) - lesser omentum
Dorsal mesogastrium 1.along the greater curvature- greater omentum
2. near the fundus- gastrosplenic ligament
3. near the cardiac end- gastrophrenic ligament
1
, -Visceral,
Anterior – Anterior abdominal wall
Left costal margin
Diaphragm
Left lobe of liver
Posterior (Stomach bed) –
Pancreas
Transverse colon
Left kidney
Left suprarenal gland
Spleen
Splenic artery
▫Are separated from stomach by the lesser sac
Superior – left dome of diaphragm
Inferior – coils of intestine
Functions
Storage of food
Mechanical grinding and digestion
Prevent reflux
Prevent digestion and damage of its wall
Controlled release of food at pylorus
Absorption (H2O, Ethanol)
Intrinsic factor
Mechanisms to prevent gastroesophageal reflux
Physiological sphincter at the gastroesophageal junction
o Transverse mucosal folds of gastroesophageal junction
o Sphincteric action of right crus of diaphragm
Acute angle of entrance of esophagus into the stomach
The positive intra-abdominal pressure compresses the abdominal part of esophagus.
2
