
The renal capsule is a tough fibrous layer surrounding the
kidney
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...
and covered in a layer of perirenal fat known as the
adipose capsule of kidney. The adipose capsule is sometimes included in the structure of the renal capsule. It provides some protection from trauma and damage. The renal capsule is surrounded by the
renal fascia. Overlying the renal fascia and between this and the
transverse fascia
The transversalis fascia (or transverse fascia) is the fascial lining of the anterolateral abdominal wall situated between the inner surface of the transverse abdominal muscle, and the preperitoneal fascia. It is directly continuous with the ilia ...
is a region of
pararenal fat.
The renal capsule resists stretching, limiting renal swelling, with important implications for renal circulation. Stretching of the renal capsule due to swelling of the kidney causes flank pain.
Structure
The renal capsule surrounds the
functional tissue of the kidney, and is itself surrounded by a fatty adipose capsule, fascia, and fat. From the inner part of the kidney to outside the kidney, the positioning of the capsule is:
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renal medulla
The renal medulla (Latin: ''medulla renis'' 'marrow of the kidney') is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the renal pyramids. Blood enters into the kidney via the renal artery, which ...
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renal cortex
The renal cortex is the outer portion of the kidney between the renal capsule and the renal medulla. In the adult, it forms a continuous smooth outer zone with a number of projections ( cortical columns) that extend down between the pyramids. I ...
# renal capsule
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adipose capsule of kidney (or perirenal fat, or perinephric fat)
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renal fascia
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pararenal fat
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peritoneum
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesotheli ...
(anteriorly), and
transverse fascia
The transversalis fascia (or transverse fascia) is the fascial lining of the anterolateral abdominal wall situated between the inner surface of the transverse abdominal muscle, and the preperitoneal fascia. It is directly continuous with the ilia ...
(posteriorly).
Sometimes the adipose capsule of the kidney also known as the perirenal fat, is regarded as a part of the renal capsule.
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See also
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Renal medulla
The renal medulla (Latin: ''medulla renis'' 'marrow of the kidney') is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the renal pyramids. Blood enters into the kidney via the renal artery, which ...
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Renal pyramid
The renal medulla (Latin: ''medulla renis'' 'marrow of the kidney') is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the renal pyramids. Blood enters into the kidney via the renal artery, which ...
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Renal artery
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Renal vein
References
External links
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{{kidney
Kidney anatomy