THE ABDOMINAL CAVITY. 1615 



In the use of oesophageal instruments the normal curves, measurements, and 

 constrictions should be remembered, as should the possible relation of abnormal 

 narrowing- to abscess, aneurism, or thoracic disease. The curve made by the roof 

 of the mouth, the pharynx, and the beginning of the oesophagus should be some- 

 what straightened out by throwing the patient's head slightly back ; the tongue and 

 anterior pharyngeal wall should be pulled forward or pushed in that direction by a 

 finger in the pharynx. The point of the instrument should be guided past the 

 epiglottis and brought in contact with the posterior wall of the pharynx before it is 

 pushed downward. This wall — like the upper wall of the urethra — is the more 

 fixed and should guide the instrument safely into the gullet, except in cases of 

 pressure of diverticula. The beginning of the procedure may be facilitated by 

 voluntary deglutition on the part of a non-anaesthetized patient. 



In some cases, especially in children, it is preferable to pass the instrument 

 through the nose to avoid the struggle to keep the mouth open. 



THE ABDOMINAL CAVITY. 



The general shape of the abdominal cavity is best understood by dividing it into 

 three imaginary zones, one above the lumbar region of the spine, one opposite to it, 

 and one below it. The anterior wall is but slightly convex. The upper zone, 

 excepting a small part in front, is within the cage of the thorax, from which it is 

 separated by the dome of the diaphragm, the lower part of which is nearly vertical 

 and posterior to the abdominal viscera. This zone is very capacious. The second 

 zone, bounded behind by the convexity of the lumbar spine, which is broadened on 

 each side by the psoas muscle, is very shallow in the middle, the antero-posterior 

 diameter not being more than 5 cm. (2 in.). At the sides it is deep, extending into 

 the hollow of the lower ribs. Thus it presents two deep lateral recesses connected by 

 a shallow median portion. The lowest zone, below the promontory of the sacrum, 

 consists in the middle of both abdominal cavity proper and of the cavity of the true 

 pelvis ; for, owing to the inclination of the pelvis, the promontory is near the level 

 of the anterior superior spines of the ilia. On each side of this deep median portion 

 the lower zone is bounded behind by the shallow iliac fossae, rendered yet more so 

 by the ilio-psoas muscles. The deep lateral divisions of the middle zone pass with- 

 out interruption into these shallow ones. 



It has been so long the custom to divide the abdomen into nine regions by 

 drawing two vertical and two transverse lines on the anterior wall, that the names 

 applied to these conventional regions must be retained for general and vague use, 

 although the method is inadequate for accurate description. ^ Hardly two authorities 

 agree as to the location of the lines, but for general purposes the following suffices. 

 Draw a vertical line upward from the middle of Poupart's ligament on each side. 

 Let the upper transverse line cross these at their points of contact with the lower 

 borders of the costal cartilages ; let the lower line connect the anterior superior spines 

 of the ilia. The three middle regions thus mapped out are named, from above down- 

 ward, epigastric, iimbi/ical, and hypogastric ; the lateral ones, the right and left 

 hypochondriac, lumbar, and iliac. The advantage of this method is that the vertical 

 lines approximately represent the borders of the median divisions of the two lower 

 zones, and the lower cross-line is near the level of the sacral promontory. 



The abdominal cavity is lined by a serous membrane, \}^<t peritoneum, which, in 

 addition to covering the walls of the space, forms a more or less extensive investment 

 for the abdominal organs. The latter, however, all lie really without the cavity of 

 the peritoneal sac, the serous membrane being pushed in by the viscera. When the 

 latter remain attached to the body-wall, as the kidneys, the peritoneal reflection is 

 limited ; if, on the contrary, the organ becomes otherwise free, as the small intestine, 

 the serous covering forms practically a complete investment. The latter is, however, 

 never absolutely complete, since there is always an uncovered area through which 

 the blood-vessels, lymphatics, and nerves reach the organs. The detailed description 

 of the complex relations of the peritoneum will be given later (page 1740) ; suffice it 



' The information conveyed by this method is of the same nature as that given by saying 

 that Boston is north of Washington and Chicago west of it. 



