Supracolic Compartment with Stomach, Liver and Spleen Flashcards
Click on Answer for transverse section images of the abdomen.
Click on Answer to view images of the various vessels supplying this region.
The stomach is the widest and most distensible part of the alimentary canal between the esophagus and the duodenum. State its functions.
- Forms a reservoir of food.
- Mixes food with gastric secretions to form a semifluid substance called chyme.
- Controls the rate of delivery of chyme into the small intestine to allow proper digestion and absorption in the small intestine.
- Hydrochloric acid secreted by the gastric glands destroys bacteria present in the food and drink.
- Castle’s intrinsic factor present in the gastric juice helps in the absorption of vitamin B12 in the small intestine.
State the location of the stomach.
Situated in the upper left part of the abdomen occupying left hypochondriac, umbilical, and epigastric regions. It extends obliquely from the left hypochondriac region into the epigastric region.
Further notes:
⚚ The stomach is mostly “J” shaped. Its long axis passes downward, forward, and to the right and finally backward and slightly upward. It tapers from the fundus on the left of the median plane to the narrow pylorus slightly to the right of the median plane.
⚚ Both the shape and position of the stomach vary greatly according to the build of an individual. It is:
1. High and transverse (steer-horn type) in short obese persons.
2. Low and elongated in tall and weak persons.
State the external features that the stomach presents.
- Two ends: Cardiac and pyloric.
- Two curvatures: Greater and lesser.
- Two surfaces: Anterior (anterosuperior) and posterior (posteroinferior).
State the difference between cardiac and pyloric orifices in terms of anatomical sphincters.
The cardiac orifice does not have an anatomical sphincter but is guarded by the physiological sphincter while the pyloric orifice has anatomical pyloric sphincter formed by the thickening of a circular coat of muscle assisted by a deep set of longitudinal fibres of the stomach.
Morphology of lesser curvature of stomach?
⚚ Concave.
⚚ Forms the shorter right border of the stomach.
⚚ The angular notch/incisura angularis on the lesser curvature indicates the junction of the body and pyloric part.
⚚ The lesser curvature provides attachment to the lesser omentum.
morphology of greater curvature of stomach
⚚ Convex.
⚚ Forms the longer left border of the stomach.
⚚ At its upper end this curvature presents a cardiac notch which separates it from the left aspect of the esophagus.
⚚ The greater curvature provides attachment to the greater omentum, gastrosplenic, and gastrophrenic ligaments.
Name the four parts of the stomach.
- Cardiac part (or cardia)
- Fundus
- Body
- Pyloric part
- [Diagram]
Why does gastric pain sometimes imitate the pain of angina pectoris?
Because superiorly, the fundus usually reaches the level of the left 5th intercostal space just below the nipple.
The pyloric part is divided into three parts. State them.
- Pyloric antrum is the proximal wide part which is separated from the pyloric canal by an inconstant sulcus, sulcus intermedius present on the greater curvature. It is about 3 inches (7.5 cm) long and leads into the pyloric canal.
- Pyloric canal is a distal narrow and tubular part measuring 1 inch (2.5 cm) in length. It lies on the head and neck of the pancreas.
- Pylorus (Greek gatekeeper) is the distal most and sphincteric region of the pyloric canal. The circular muscle fibres are markedly thickened in this region, which control the discharge of stomach contents through the pyloric orifice into the duodenum.
Note: The position of the pyloric orifice is indicated on the surface by (a) a circular sulcus—pyloric constriction produced by the underlying pyloric sphincter or pylorus; and (b) the prepyloric vein of Mayo on the anterior surface of the pylorus.
arterial supply of stomach
The stomach has rich arterial supply derived from the coeliac trunk and its branches. The arteries supplying the stomach are:
1. Left gastric artery, a direct branch from the coeliac trunk.
2. Right gastric artery, a branch of the common hepatic artery.
3. Left gastroepiploic artery, a branch of the splenic artery.
4. Right gastroepiploic artery, a branch of the gastroduodenal artery.
5. Short gastric arteries (five to seven in number), branches of the splenic artery.
Note that the veins of the stomach correspond to the arteries and drain directly or indirectly into the portal vein.
