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.
The kidney is held in place by the attachment to the diaphragm of the perirenal fascia, by its vessels, peritoneum, ureter, and by intra-abdominal pressure. Normally it cannot be felt beneath the edge of the ribs. It, however, readily becomes displaced and slides down so as to be felt below the costal margin; it is then called a movable kidney. If the displacement becomes more marked it may descend into the iliac fossa or even toward the median line; then it is called a floating or wandering kidney. In some instances it slides around without pushing the peritoneum markedly forward, hence it then has no mesentery or pedicle. In other cases it stretches the peritoneum in front of it and has sufficient of a mesentery to allow it to come in contact with the anterior abdominal wall.
Fig. 435. - Transverse section of the kidney. The renal artery is seen dividing into anterior and posterior branches. Incisions into the organ are to be made as indicated on the posterior surface just back of the prominent edge.
As the kidney enlarges it does so in a forward and downward direction. As it comes forward it may go to the outer side of the colon, to its inner side, or carry the colon directly in front of it. Greig Smith ("Abdominal Surgery," p. 868) states that on the right side the ascending colon passes over the front and to the inner side of the growth, while on the left side the descending colon passes to the front and a little to the outer side. Renal tumors may be mistaken for tumors of the liver and gall-bladder, spleen, and ovaries. A longitudinal coil of resonant intestine passing over the tumor is prima facie evidence of its being renal in character. Renal growths appear as more or less spherical tumors which can in some cases be palpated around their entire circumference. If one portion only can be felt, the remainder leads towards the loin; in gall-bladder tumors (cysts) the base of the growth leads toward the liver and is in contact with the abdominal wall, overlying the colon and small intestine. In splenic tumors a notch can sometimes be felt and the growth makes its appearance from above, down under the left costal margin.
The kidney is frequently involved in suppurative affections. Calculi and tuberculous diseases are of that nature, and pyogenic infection may creep up from the bladder, producing pyelonephritis, or surgical kidney. The pus may be extrarenal, involving the adipose capsule and perirenal fascia; it commonly points in the loin. As this fascia is open below and to the inner side the pus may descend to the iliac fossa or follow inside the sheath of the psoas muscle beneath Poupart's ligament. It may work its way up along the psoas under the ligamentum arcuatum internum and empty through the lung, or perforate the diaphragm at the hiatus and so reach the lung (page 425). We have seen it work along the under surface of the liver and point anteriorly at the costal margin. It may also rupture into the duodenum or colon. Sometimes it goes posteriorly and perforates the lumbar fascia to appear at the outer edge of the latissimus dorsi and erector spinas muscles in the iliocostal space, or at the triangle of Petit (page 394).
Fig. 436. - Diagrammatic longitudinal section, showing relations of supporting tissue to right kidney. (Gerota).