1890 HUMAN ANATOMY. 



position the kidney is so overlapped by the lower thoracic wall that the resonance 

 and resistance of the loin have at best but little relation to it (page 1873). 



Of course, obstruction of the ureter from other causes — as valvular folds at the 

 ureteral orifice, thought to follow a congenital exceptionally oblique insertion of the 

 ureter into the pelvis (Virchow), or brought about by distention of the pelvis 

 (Simon), or aggravated by swelling of the pelvic mucosa (Kiister, Cabot) — or ob- 

 structive disease of any part of the lower urinary tract may also result in a -hydrone- 

 phrosis which, if infection occurs, — as it often does, — hecon\Q.S3i pyonephrosis. Either 

 a purulent collection thus formed or an abscess originating in the renal structure 

 (pyogenic or tuberculous infection) may find its way into the fatty and connective 

 tissue of the loin, — perinephric tissue, — or suppuration may reach that region from 

 other sources or may occur there primarily. 



Perinephric abscess is characterized by certain symptoms which should be studied 

 in connection with the anatomy of the region, as (<a;) pain, radiating to the lower ab- 

 domen, genitalia, or thigh, — i.e., in the distribution of the ilio-hypogastric, ilio-ingui- 

 nal, anterior crural, obturator, and other branches of the lumbar plexus ; ((^) flexion 

 and adduction of the thigh, from irritation of the motor filaments of the same nerves, 

 especially if the abs(?ess is about the lower pole of the kidney, and therefore in inti- 

 mate relation with the third and fourth lumbar nerves, from which the supply of the 

 flexors and adductors is chiefly derived ; (^) bending of the body towards the 

 affected side, towards which the concavity of a lateral lumbar curve in the spine is 

 directed, — a symptom which, like b, may be due either to muscular spasm or to an 

 instinctive effort to increase the loin space ; (^) intestinal disturbance from the 

 proximity of the abscess to the colon, into which it may open. Such abscess may 

 also penetrate the lumbar 'aponeurosis and the quadratus lumborum muscle and ap- 

 pear in the loin at the outer border of the erector spinse between the latissimus dorsi 

 and external oblique (the lower part of which interval is Petit' s triangle, g.v.), or may 

 descend by gravity into the pelvis, or may — very exceptionally — open into the peri- ' 

 toneal cavity. 



Abscess of the kidney which penetrates the renal capsule to reach the perirenal 

 region usually does so at a non-peritoneal area of the kidney surface, but does not 

 necessarily reach the loin. As reference to the relations of the kidney (page 1873) 

 will show, the pus may be evacuated directly into the colon or duodenum, or more 

 frequently— because the apposed areas are covered with peritoneum which favors 

 limiting adhesions — into the stomach or liver, or through the diaphragm into the 

 base of the chest. 



Renal calcuhis produces symptoms which are analogous to those described 

 above as associated with suppurative disease in or about the kidney, and which — 

 apart from haematuria and pyuria and the physical evidence of the presence of a stone, 

 such as is afforded by the X-rays — depend for their interpretation upon a knowledge 

 of the renal reflexes, — i.e., of the association of the small and lesser splanchnics and 

 the tenth to twelfth dorsal and first lumbar spinal segments with the sensory and 

 motor nerves derived from the same segments. These symptoms are, in part, pain 

 radiating to the genitalia, vesical irritability, nausea and vomiting, rectal tenesmus, 

 and retraction of the testicle. The last-named symptom is more marked in children 

 and young persons, in whom the gland is often drawn up to the external ring or 

 ^ven into the inguinal canal. After puberty, as the testis increases in weight and the 

 cremaster grows feebler with age, the retraction becomes less obvious (Lucas). 



It has been suggested that occasionally the sudden exacerbation of pain occur- 

 ring at night when the patient is at rest may be due to the passage of flatus along 

 the colon that presses against the kidney (Jacobson). 



The aching pain beginning at the lower edge of the last rib, in the angle between 

 it and the spine, and extending along the edge of the rectus muscle below the level 

 of the umbilicus, is probably reflected along the last dorsal nerve, as it is almost 

 certainly relieved by operations in which that nerve is divided, but the stone is not 

 found (Lucas). 



Disease of the kidney, when non-suppurative, has but little obvious anatomical 

 bearing. It may be noted, however, that the time-honored practice of applying 

 counter-irritants and heat to the loin in renal congestions has a scientific basis in the 



