Kidneys

The kidney (Ren, Greek. Nephros) is a pair of excretory organ that forms and removes urine. The kidney is bean, dark red color, dense consistency. The size of the kidney in an adult is as follows: length 10-12 cm, width 5-6 cm, thickness 4 cm. The mass of the kidney ranges from 120 to 200 g. The surface of the kidney in an adult person is smooth. There are a more convex front surface (Facies Anterior) and a less convex rear surface (Facies Posterior), the upper end (Extremmitas Superior), as well as a convex lateral edge and a concentrated medial edge (Margo medialis). In the middle department of the medial region there is a recess - renal gate (Hilum Renalis). The renal gate includes the renal arteries and nerves, the ureter, renal vein, lymph vessels come out of them. Blood vessels and nerves form the so-called renal leg. The renal gate move into an extensive recess that is drawn into the substance of the kidneys and called the renal sinus (sinus renalis). In the renal sinus are small and large renal cups, renal pelvis, blood and lymph vessels, nerves and adipose tissue.

The kidney parenchyma consists of two sharply different layers: external and internal. The outer layer, the cortical substance of the kidney (Cortex Renalis), or the bark of the kidney, is abundantly blood supply, as a result of which it has an intense red color. Crimean substance occupies the entire peripheral (external) part of the organ; Its thickness is 1 cm. The inner layer, known as the brain of the kidney (Medulla Renalis), is significantly inferior to the cortical substance in terms of the intensity of blood supply. Structurally, brain substance is devoid of homogeneity. It is divided into 8-18 conical structures that are known as renal pyramids (Pyramides Renales) located fan-shaped: their base is facing the kidney bark, and the top (renal papilla, Papilla Renalis) is located in the renal gate (Hilum Renale). Each of the pyramids is separated from the other renal pillars (Columnae Renales), which are areas of the cortical substance of the kidney, which are introduced into the brain substance.

The renal pyramid and part of the cortical substance above it are called the renal share. In the brain substance, two zones are distinguished - external and internal. The area of the outer zone of the brain substance, bordering the cortical substance of the kidney, is called corticomedullary compound. From it, the so-called brain rays (Radii Medullaries) go to the bark of the kidneys, which are the functional structures of the cortical substance - direct segments of the proximal tubules, thick ascending segments and cortical collective tubes. The internal zone (Zona Interna) of the brain substance ends with the area of the renal papity free from the structural elements of the nephron. The papillae are pierced with 10-25 in small holes, which are terminal segments of renal collecting tubes (Bellini ducts). The mouths of these ducts are around the top of the papilla.

The renal papillae are opened in small renal cups {Calitses Renales minores) - the first structural elements of the urinary tract, connecting the kidney parenchyma with the urinary system, which is represented by urethics, uric bubble and urethra.

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Topography of the kidneys

The kidneys are located in the lumbar region (regio lumbalis) on both sides of the spinal column, on the inner surface of the posterior abdominal wall and lie retroperly (retroperitoneal). The upper ends of the kidneys are close to each other up to 8 cm, and the lower ends are settled from each other by II cm. The longitudinal axis of the right and left kidneys at the top intersect at an angle open downward. The left kidney is located slightly higher than the right, 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 of the III 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 located as follows: the XII rib crosses the rear surface of the left kidney almost in the middle of its length, and the right one - approximately on the border of its upper and middle thirds. There are individual characteristics of the kidney topography. The high and low location is different. In 11 % of women, the lower end of both buds touches the ridge of the iliac bones.

The kidneys are in complex relationships with neighboring organs. The back surface of the kidney, along with its shells, is adjacent to the lumbar part of the diaphragm, the square muscle of the lower back, the transverse muscle of the abdomen and the large lumbar muscle, which form for the kidney, the renal bed. The upper end of the kidney is in contact with the adrenal gland. The front surface of the kidneys is covered with a leaf of the parietal peritoneum at its larger length and is in contact with some internal organs. The liver is adjacent to the upper two-thirds of the front surface of the right kidney, and the right bend of the colon is adjacent to the lower third. The descending part of the duodenum is adjacent to the medial edge of the right kidney. The front surface of the left kidney in the upper third is in contact with the stomach, in the middle one - with the pancreas, and in the lower - with the loops of the skin. The lateral edge of the left kidney is adjacent to the spleen and the left bend of the colon. The normal topographic arrangement of the kidneys is provided by its fixing apparatus, which includes the renal bed, the “renal leg”, the kidney shell (especially the renal fascia).

Of great importance is intra-abdominal pressure, maintained by contraction of the abdominal muscles.

Kids' shells

A few shells are distinguished by the kidney. Outside, the kidney is covered with a thin connective tissue plate with a fibrous capsule (Capsula fibrosa), which can be easily separated from the substance of the kidney. Substantine from the fibrous capsule is a significant thickness of the fat capsule (Capsula adiposa), penetrating through the renal gate into the renal sinus. The fat capsule is most pronounced on the back of the kidney, where a peculiar fat pillow is formed - the peripheated fatty body (Corpus adiposum pararenale). With a rapid decrease in the thickness of the fat capsule (with rapid weight loss), the kidney can become mobile (wandering kidney).

Based on the fat capsule, the kidney is covered (in the form of a bag open downward) renal fascia (Fascia Renalis), consisting of two sheets - premised and behind the prospective. The preferential sheet covers the front of the ice kidney, renal vessels, the abdominal part of the aorta, the lower hollow Vienna and continues in front of the spine on the right kidney. Be protected by the renal fascia on the left and on the right is attached to the side departments of the spinal column. The lower edge of the pre- and behind the leaf of the renal fascia is not interconnected. The renal fascia, through heavy fibrous connective tissue, which penetrate the fat capsule, is connected to the fibrous capsule of the kidney. Ahead of the premise sheet of the renal fascia is the Parent sheet of the peritoneum.

Kidney x-ray

On the radiograph, the contours of the kidneys are smooth, have the form of arcuate lines; The shadow of the kidneys is homogeneous. The upper boundary of the shadow of the left kidney reaches the XI ribs and the middle of the body of the XI thoracic vertebra, and the right - the lower edge of the same vertebra. The shape and size of the kidney are detected by administering oxygen or gas into the retroperitoneal space - pneumoraloperitoneum. With pyelography (after the introduction of a contrast matter into the bloodstream or retrograde through the ureter), the shadow of the renal pelvis is at the level of tel I and II lumbar vertebrae, the shadows of the renal cups are visible. The condition of the arterial channel of the kidney is detected using arteriography.