Topography of the kidneys
The kidneys are located in the lumbar region (regio lumbalis) on either side of the vertebral column, on the inner surface of the posterior abdominal wall and lie retroperitoneally (retroperitoneally). The upper ends of the kidneys are approximated to each other up to 8 cm, and the lower ends are separated from each other by II cm. The longitudinal axis of the right and left kidneys intersect at the top at an angle open downward. The left kidney is slightly higher than the right kidney, which lies directly under the liver. The upper end of the left kidney is at the level of the middle of the XI thoracic vertebra, and the upper end of the right kidney corresponds to the lower edge of this vertebra. The lower end of the left kidney lies at the level of the upper edge III of the lumbar vertebra, and the lower end of the right kidney is at the level of its middle. In relation to the ribs, the kidneys are arranged as follows: the XII rib crosses the posterior surface of the left kidney almost at the middle of its length, and the right one roughly at the border of its upper and middle thirds. There are individual features of the topography of the kidneys. Their high and low location is different. In 11% of women, the lower end of both kidneys touches the crest of the iliac bones.
The kidneys are in complicated relationships with neighboring organs. The posterior surface of the kidney, along with its membranes, is attached to the lumbar part of the diaphragm, the square muscle of the waist, the transverse abdominal muscle and the large lumbar muscle, which form a kidney for the kidney . The upper end of the kidney is in contact with the adrenal gland. The anterior surface of the kidneys on the larger length is covered with a leaf of the parietal peritoneum and comes into contact with some internal organs. To the upper two thirds of the anterior surface of the right kidney is the liver, and to the lower third - the right bend of the colon. The medial margin of the right kidney is the descending part of the duodenum. The anterior surface of the left kidney in the upper third touches the stomach, in the middle - with the pancreas, and in the lower - with the loops of the jejunum. The lateral margin of the left kidney is due to the spleen and left curvature of the colon. The normal topographic location of the kidneys is provided by its fixation apparatus, which includes the kidney bed, the "renal pedicle", the kidney shell (especially the renal fascia).
Of great importance is intra-abdominal pressure, supported by contraction of the abdominal muscles.
In the kidney, several membranes are isolated. Outside, the kidney is covered with a thin connective tissue plate with a fibrous capsule (capsula fibrosa), which can be easily separated from the kidney substance. Outside the fibrous capsule is a significant thickness of the fat capsule (capsula adiposa), which penetrates through the renal gates into the renal sinus. The fat capsule is most pronounced on the posterior surface of the kidney, where a peculiar fat pad is formed - the perineal fat body (corpus adiposum pararenale). With a rapid reduction in the thickness of the fat capsule (with rapid weight loss), the kidney can become mobile (a wandering kidney).
Outside the fatty capsule, the kidney is covered (in the form of an open bottom of the sac) by the fascia renalis, consisting of two sheets - the preference and the back-bone fascia. The preference sheet covers the front of the left kidney, kidney vessels, the abdominal part of the aorta, the lower vena cava and extends in front of the spine to the right kidney. The posterior- kidney fascia of the renal fascia on the left and right is attached to the lateral sections of the vertebral column. The lower edge of the pre- and posterolateral leaf of the renal fascia is not joined together. Renal fascia by means of strands of fibrous connective tissue that permeate the fatty capsule is connected to the fibrous capsule of the kidney. Ahead of the preference sheet of the renal fascia is the parietal leaflet of the peritoneum.
Renal X-ray of the kidney
On the roentgenogram, the contours of the kidney are smooth, have the appearance of arcuate lines; the shadow of the kidneys is uniform. The upper border of the shadow of the left kidney reaches the XI rib and the middle of the body XI of the thoracic vertebra, and the right - the lower edge of the same vertebra. The shape and magnitude of the kidney are detected by introducing oxygen or gas into the retroperitoneal space - pneumoreteroperitoneum. When pyelography (after the introduction of contrast agent into the blood or retrograde through the ureter), the shadow of the renal pelvis is at the level of the bodies of I and II lumbar vertebrae, the shadows of the kidney cups are visible. The condition of the arterial bed of the kidney is revealed through arteriography.