THE KIDNEYS 1357 



below the lower edge of each kidney. (2) A vertical line carried upward to the costal arch from 

 the middle of Poupart's ligame-it has one-third of the kidney to its outer side and two-thirds to 

 its inner side i. e., between this line and the median line of the body." In adopting these lines 

 it must be borne in mind that the axes of the kidneys are not vertical, but oblique,and if con- 

 tinued upward would meet about the ninth thoracic vertebra. Posteriorly: The upper end of the 

 left kidney would be defined by a line drawn horizontally outward from the spinous process of the 

 eleventh thoracic vertebra, and its lower end by a point two inches (5 cm.) above the iliac crest. 

 The right kidney would be half to three-quarters of an inch lower. Morris lays down the fol- 

 lowing rules for indicating the position of the kidney on the posterior surface of the' body: '"'(I) 

 A line parallel with, and one inch from, the vertebral column, between the lower edge of the tip 

 of the spinous process of the eleventh thoracic vertebra and the lower edge of the spinous 

 process of the third lumbar vertebra. (2) A line from the top of this first line outward at right 

 angles to it for two and three-quarter inches. (3) A line from the lower end of the first trans- 

 versely outward for two and three-quarter inches. (4) A line parallel to the first and connecting 

 the outer extremities of the second and third lines just described." 



The hilum of the right kidney is two inches from the mesal plane; the hilum of the left one 

 and one-half inches from the mesal plane. A line joining the two hili crosses the vertebral 

 column opposite the disk between the first and second lumbar vertebrae. 



Applied Anatomy .Cases of congenital absence of a kidney, of atrophy of a kidney, and 

 a horseshoe kidney are of great importance, and must be duly taken into account when'neph- 

 rectomy is contemplated. A more common malformation is where the two kidneys are fused 

 together. They may be only joined together at their lower ends by means of a thick mass of 

 renal tissue, so as to form a horseshoe-shaped body, or they may be completely united, forming 

 a disk-like kidney, from which two ureters descend into the bladder. These fused kidneys are 

 generally situated in the middle line of the abdomen, but may be misplaced as well. 



One or both kidneys may be misplaced as a congenital condition, and remain fixed in this 

 abnormal position. They are then very often misshapen. They may be situated higher or lower 

 than normal or removed farther from the spine than usual or they may be displaced into the 

 iliac fossa, over the sacroiliac joint, on to the promontory of the sacrum, or into the pelvis be- 

 tween the rectum and bladder or by the side of the uterus. In these latter cases they may give 

 rise to very serious trouble. The kidney may also be misplaced as a congenital condition, but 

 may not be fixed. It is then known as a floating kidney. It is believed to be due to the fact 

 that the kidney is completely enveloped by peritoneum, which then passes backward to the 

 vertebral column as a double layer, forming a mesonephron, which permits of movements taking 

 place. The kidney may also be misplaced as an acquired condition; in these cases the kidney is 

 mobile in the tissues by which it is surrounded, either moving in or moving with its fatty capsule. 

 This condition is known as movable kidney (nephroptosis), and is more common in the female 

 than in the male, and on the right than the left side. If a displaced kidney becomes fixed in an 

 abnormal position, it is said to be dislocated. Movable kidney cannot be distinguished from 

 floating kidney until the kidney is exposed by incision. Other malformations are the persist- 

 ence of the fetal lobulation; the presence of two pelves or two ureters to the one kidney. In 

 some rare instances a third kidney may be present. 



The kidney is embedded in a large quantity of loose fatty tissue, and is but partially covered 

 by peritoneum; hence rupture of this organ is not nearly so serious an accident as rupture of 

 the liver or spleen, since the extravasation of blood and urine which follows is, in the majority 

 of cases, outside the peritoneal cavity. Occasionally the kidney may be bruised by blows in the 

 loin or by being compressed between the lower ribs and the ilium when the body is violently 

 bent forward. This is followed by a little transient hematuria, which, however, speedily passes 

 off. Occasionally, when rupture involves the pelvis of the ureter or the commencement of the 

 ureter, this duct may become blocked, and hydronephrosis follows. 



The loose cellular tissue around the kidney may be the seat of suppuration, constituting 

 pen'nephritic abscess. This may be due to injury, to disease of the kidney itself, or to extension 

 of inflammation from neighboring parts. The abscess may burst into the pleura, causing 

 empyema; into the colon or bladder; or may point externally in the groin or loin. Tumors of the 

 kidney, of which, perhaps, sarcoma in children is the most common, may be recognized by their 

 position and fixity; by the resonant colon lying in front of it; by their not moving with respira- 

 tion; and by their rounded outline, not presenting a notched anterior margin like the spleen, with 

 which they are most likely to be confounded. The examination of the kidney should be bimanual; 

 that is to say, one hand should be placed in the flank and firm pressure made forward, while 

 the other hand is buried in the abdominal wall, over the situation of the organ. Manipulation 

 of the kidney frequently produces a peculiar sickening sensation and some faintness. 



The kidney is frequently attacked surgically. It may be exposed and opened for exploration 

 or the evacuation of pus (nephrotomy); it may be incised for the removal of stone (nephro- 

 Kihotamy)', it may be sutured when wounded (nephrorrhaphy}; it may be fixed in place by 

 sutures (nephropexy) or gauze pads when movable or floating; or it may be removed (nephren- 

 tomy). 



