on 
THE BACK: 1193 
which is the situation at which the stethoscope is placed in order to hear the 
sound produced by the passage of fluid into the stomach. 
Clinically it is important to bear in mind the relation of the esophagus to the trachea and 
bronchi (especially to the left bronchus), to the left recurrent laryngeal nerve, to the bronchial 
and posterior mediastinal glands, to the descending thoracic aorta, and to the right posterior 
mediastinal pleura. Uleers of the cesophagus are liable to open into either the trachea, the left 
bronchus, or the right pleura. 
The veins of the lower end of the esophagus open partly into the systemic veins and partly 
into the portal system; like those at the lower end of the rectum they are hable to become 
varicose in conditions which give rise to chronic interference with the portal circulation. 
The lymphatics of the upper part of the cesophagus open into the lower carotid glands, the 
remainder into the posterior mediastinal glands. 
The cesophagus is very distensible in the transverse but not in the antero- posterior direction, 
hence the most useful forceps for removing foreign bodies from the cesophagus are those which 
open laterally. 
THE BACK. 
In the middle line of the back is the spinal furrow, which is deepest in the 
lower dorsal and upper lumbar regions, where the erectores spinze muscles are most 
prominent. Over the upper sacral region, where the erectores spine: muscles are 
tendinous, 1s a flattened area forming an equilateral triangle, the angles of which 
correspond respectively to the posterior superior spines of the two iliae bones and the 
third sacral spine. The vertebral spines can be palpated at the bottom of the spinal 
furrow; they become more distinct when the spine is flexed, and, as pointed out 
by Holden, they become mapped out by reddened areas when friction is applied 
along the furrow. The identification and counting of the spimes will be facilitated 
if it be remembered that the first dorsal is more prominent than the vertebra 
prominens (seventh cervical), that the third dorsal is on a level with the root of 
the spine of the scapula, the seventh dorsal with its imferior angle, the fourth 
lumbar with the highest part of the iliac crest, and the second sacral with the 
posterior superior iliac spine. 
Above the spine of the scapula is the suprascapular region, which is padded by a 
thick mass of muscle consisting of the supra-spmatus and levator anguli scapulie, 
covered by the upper part of the trapezius; the two latter muscles may be thrown 
into relief by shrugging the shoulders. 
In the interscapular region are the rhomboid muscles, which are thrown into 
prominence by bracing back the shoulders. 
Below the inferior angle of the scapula the last five ribs can readily be felt 
external to the erector spine muscle; when the twelfth rib does not reach 
beyond this muscle, the eleventh rib will be mistaken for it, unless the ribs be 
counted from above downwards. 
The lower border of the trapezius is indicated by a lne extending upwards and 
outwards from the twelfth dorsal spine to the root of the spine of the scapula; the 
upper border of the latissimus dorsi by a line extending from the sixth dorsal spine 
transversely outwards across the angle of the scapula. Between these two muscles 
and the lower part of the vertebral border of the scapula is a triangular area, the 
floor of which is formed by the rhomboideus major muscle and the sixth costal 
interspace. 
The outer border of the erector spine is indicated on the surface by drawing a 
line from a point on the iliae crest 34 in. (four fingers’ breadth) from the middle 
line, upwards and shehtly outwards to the angles” of the ribs. The outer border 
of the quadratus lumborum, which passes upwards and slightly inwards, lies a little 
external to that of the erector spinze at the crest, and a ‘little internal to it at the 
— twelfth rib. 
The anatomy of the muscles and fascize which complete the abdominal wall 
between the last rib and the iliac crest is of great importance in connexion with 
operations in the region of the loin. The space between the last rib and the ilac 
crest varies greatly according to the length of the former, and according to the general 
shape of the chest and slope of the ribs. Asa rule, the tip of the twelfth rib lies 
about two inches vertically above the centre of the iliac crest. From a surgical 
