Capacity about 2 pints. The cardiac orifice lies opposite the eleventh dorsal vertebra, (Fig. XIX, 2) and is situated about 4 inches away from the surface. It corresponds in position to a point on the seventh costal cartilage 1/2 inch away from the outer border of the sterno-xiphoid junction. The seventh costal cartilage is the lowest of the series of cartilages which articulate in front with the mesial sterno-xiphoid bar, and forms, therefore, the upper lateral boundary of the epigastric triangle. The pyloric orifice lies opposite the first lumbar vertebra, (Fig. XIX, 3.) and corresponds in position to a point in the transpyloric plane just to the right of the middle line.
The lesser curvature is represented by a curved line, convexity to the left, uniting the above two points. The greater curvature, in the moderately distended condition of the stomach, ascends to the lower border of the left fifth costal cartilage and rib, lying immediately above and behind the apex of the heart. Sweeping then downwards, the greater curvature usually cuts the left costal margin at some part of the ninth costal cartilage, and finally curves upwards and inwards to the pylorus.
The upper limit of the fundus of the stomach corresponds to the level of the left dome of the diaphragm. (Fig. XX, 1.)
Total length, about 10 inches. (Fig. XIX, 4.)
Part 1 =2 inches;
Part 2 =3 to 4 inches;
Part 3 = 4 to 5 inches.
The pyloric orifice of the stomach lies opposite the first lumbar vertebra, and the first part of the duodenum is directed backwards, with a slight inclination upwards, to the right side of the body of the first lumbar vertebra.
Part 2 descends, on the right side of the median vertical plane, from the level of the first lumbar vertebra (transpyloric plane) to the level of the third lumbar vertebra (subcostal plane). The third part of the duodenum passes almost transversely across the middle line at the level of the subcostal plane, (Fig. XIX, 5.) and having reached the left side of the middle line, ascends sharply to the duodenojejunal flexure, which is placed on a level with the second lumbar vertebra, just below the transpyloric plane, and 1 to 1 1/2 inches to the left of the middle line. The duodenum is subject to great variation in position, and the description given merely represents the average situation of this loop of the small gut. The pyloric orifice of the stomach and the duodeno-jejunal flexure are both fairly constant in position, and between these two more or less fixed points the gut describes a loop which varies both in shape and in extent.