Kidneys

RELATIONS

Posterior:
The diaphragm covers roughly the upper 1/3 of each kidney. With the diaphragm travels the pleural reflection. The 12th rib crosses the kidney at approximately the lower extent of the diaphragm. The upper border of the left kidney usually extends to the upper border of the 11th rib.

The medial portion of the lower 2/3rds of the kidneys, with renal vessels and pelvis, lie against the psoas muscle.

The lateral portion of the posterior surface of the kidney lies against the quadratus lumborum and the aponeurosis of the transverses abdominus.

The lower pole of each kidney lies further from the midline than the upper pole, partially because of the psoas.

The lower pole is pushed slightly more anterior than the upper pole.

The medial aspect is rotated anteriorly at an angle of that about 30 degrees from the true coronal plane – vessels and the renal pelvis exit the hilum medially in a relatively anterior direction.

Anterior:
The right kidney lies behind the liver; it is separated from the liver by reflection of the peritoneum, except for a small area of the upper pole which comes in contact with the bare area of the liver.

The upper pole is covered by the hepatorenal ligament

The duodenum is on the medial aspect and the hilar structures of the right kidney.

The hepatic flexure of the colon (extraperitoneal) crosses the lower pole.

The adrenal gland covers the superomedial aspect of the upper pole.

With regards to the left kidney, the retroperitoneal tail of the pancreas and related
splenic vessels are applied to the upper middle portion and hilum of the kidney, superior to the pancreas tail.

The left kidney is covered by the peritoneum of the lesser sac and is related to the posterior gastric wall. The pancreatic tail and medial kidney are covered by the peritoneum of the greater sac and are related to jejunum.

The lower pole is crossed by the splenic flexure of the colon, in an extraperitoneal position.

The spleen is separated from the kidney as peritoneal reflection part of
peritoneal extension is called
splenorenal ligament.

The kidneys and adrenals are surrounded by varying degrees of perinephric or perirenal fat loosely enclosed by perirenal fascia called Gerota’s fascia.

Superiorly, Gerota’s fuses and tapers to disappear over the inferior diaphragm surface.

Medially, Gerota’s extends across the midline and is contiguous with the contralateral Gerota’s.

Inferiorly, Gerota’s remains an open potential space, containing the ureter and gonadal vessels.

It then thins inferiorly and becomes contiguous with the retroperitoneal fascia, which extends into pelvis.

In males it extends with spermatic vessels and vas deferens into the scrotum.

Gerota’s forms an important anatomic barrier around the kidney to contain pathologic processes originating from the kidney.

Cavity and Spaces:
The kidneys are situated in the abdominal cavity, in the retroperitoneum, in the renal spaces.

Superiorly, the kidneys are level with the upper border of the twelfth thoracic vertebra; inferiorly with L3.

Rightward and Leftward Positioning:
The kidneys are found posterolaterally and are relatively symmetrically placed on either side of the midline.

Craniocaudal Positioning:
The right kidney is usually 1-2 cm lower in the retroperitoneum because of the mass of the liver.

The left kidney is longer, narrower, and lies nearer to the median plane.

Long Axis:
The long axis of each kidney is directed inferolaterally and the transverse axis is directed postereolaterally.

Kidneys are very mobile and their positions vary with inspiratory and expiratory ovement of the diaphragm,as well as with changes from upright to supine to trendlenberg.

Recent Passage of a Kidney Stone – Note Position of the Stone

47628c01 kidney bladder ureter renal pelvis fx nephrolithiais mild hydronephrosis mild hydroureter stone in bladder dx recent passage of stone CTscan DavidoffMD