This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
When the stomach is moderately distended it is a pear-shaped organ lying almost entirely to the left of the median line and occupying the epigastric and left hypochondriac regions. It has an average capacity of 1 to 2 litres (about 2 1/2 pints). Its direction is an oblique one, being downward, forward, and to the right. The upper two-thirds are more longitudinal, the lower third more transverse, the two parts making an angle of 60 to 70 degrees. The part just adjoining the pylorus is slightly enlarged when the stomach is distended, and is called the antrum. The stomach is spoken of as having anterior and posterior walls, but they could just as truthfully be called superior and inferior, especially when the organ is distended. When it is relaxed it tends to hang in a more vertical position, but when it is distended it rotates on a tranverse axis, the greater curvature coming forward, and the organ assumes a more horizontal plane. When the stomach is empty it may not be relaxed but contracted. This contraction is liable to be very marked toward the middle of the organ, producing the hour-glass stomach. At other times the contraction proceeds a variable distance from the pylorus toward the cardiac extremity. In such cases instead of being pear-shaped the stomach becomes more or less tubular so as to resemble the remainder of the intestinal canal. It then differs but little in appearance from the duodenum, and the position of the pylorus is not readily recognized. If, as may normally occur, the contraction extends well over toward the cardiac end, then liquids do not lodge in the stomach but pass almost immediately through it 26 into the small intestine beyond. When this condition is found to exist, the stomach is to be recognized by its position, its attachments, and the thickness of its walls. It hangs suspended by its cardiac extremity from the oesophagus. This is beneath the seventh left costal cartilage, about an inch from the edge of the sternum and 10 cm. (4 in.) from the surface; this brings it opposite the eleventh dorsal vertebra immediately in front of the aorta. The pylorus lies just under the edge of the liver, either in the median line when the stomach is empty or, as is more often the case, 2.5 cm. (1 in.) or more to the right of the median line - a little higher up than the gall-bladder or opposite the eighth right costal cartilage and on a level with the first lumbar vertebra. The pylorus is usually a little higher in women than in men. If the liver is contracted the pylorus and adjacent portion of the stomach may be in direct contact with the anterior abdominal wall. The lesser curvature is 7.5 to 12.5 cm. (3 to 5 in.) long and passes downward, forward, and to the right.
Fig. 415. - The bed of the stomach. The stomach has been removed showing the surrounding structures.