|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
Component Parts of the Stomach.A plane passing through the incisura angularis on the lesser curvature and the left limit of the opposed dilatation on the greater curvature divides the stomach into a left portion or body and a right or pyloric portion. The left portion of the body is known as the fundus, and is marked off from the remainder of the body by a plane passing horizontally through the cardiac orifice. The pyloric portion is divided by a plane through the sulcus intermedius at right angles to the long axis of this portion; the part to the right of this plane is the pyloric antrum (Fig. 1046).
FIG. 1046 Outline of stomach, showing its anatomical landmarks. (See enlarged image)
FIG. 1047 Diagram showing shape and position of empty stomach. Erect posture. (Hertz.) (See enlarged image)
| If the stomach be examined during the process of digestion it will be found divided by a muscular constriction into a large dilated left portion, and a narrow contracted tubular right portion. The constriction is in the body of the stomach, and does not follow any of the anatomical landmarks; indeed, it shifts gradually toward the left as digestion progresses, i. e., more of the body is gradually absorbed into the tubular part (Figs. 1047, 1048, 1049).|
FIG. 1048 Diagram showing shape and position of moderately filled stomach. Erect posture. (Hertz.) (See enlarged image)
FIG. 1049 Diagram showing shape and position of distended stomach. Erect posture. (Hertz.) (See enlarged image)
Position of the Stomach.The position of the stomach varies with the posture, with the amount of the stomach contents and with the condition of the intestines on which it rests. In the erect posture the empty stomach is somewhat J-shaped; the part above the cardiac orifice is usually distended with gas; the pylorus descends to the level of the second lumbar vertebra and the most dependent part of the stomach is at the level of the umbilicus. Variation in the amount of its contents affects mainly the cardiac portion, the pyloric portion remaining in a more or less contracted condition during the process of digestion. As the stomach fills it tends to expand forward and downward in the direction of least resistance, but when this is interfered with by a distended condition of the colon or intestines the fundus presses upward on the liver and diaphragm and gives rise to the feelings of oppression and palpitation complained of in such cases. His 1 and Cunningham 2 have shown by hardening the viscera in situ that the contracted stomach has a sickle shape, the fundus looking directly backward. The surfaces are directed upward and downward, the upper surface having, however, a gradual downward slope to the right. The greater curvature is in front and at a slightly higher level than the lesser.
|Note 1. Archiv für Anatomie und Physiologie, anat. Abth., 1903. [back]|
|Note 2. Transactions of the Royal Society of Edinburgh, vol. xlv, part i. [back]|