Page 1014 - Fundamentals of anatomy physiology

&T i p s T r i c k s Chapter 26 The Urinary System 1001
To visualize the kidneys’ retroperitoneal positions, think of
each kidney as a picture on the body wall that got covered with the deep fascia surrounding the muscles of the body
over by wallpaper (the parietal peritoneum). To remember the wall. Anteriorly, the renal fascia forms a thick layer that
organs positioned entirely or partially retroperitoneally, use fuses with the peritoneum.
the mnemonic SAD PUCKER for Suprarenal (adrenal) glands,
Aorta and inferior vena cava, Duodenum, Pancreas, Ureters, In effect, each kidney hangs suspended by collagen fibers
Colon, Kidneys, Esophagus, Rectum. from the renal fascia and is packed in a soft cushion of adipose
tissue. This arrangement prevents the jolts and shocks of day-
The kidneys are held in position within the abdominal cav- to-day living from disturbing normal kidney function. If the
ity by (1) the overlying peritoneum, (2) contact with adjacent suspensory fibers break or become detached, a slight bump or
visceral organs, and (3) supporting connective tissues. Three hit can displace the kidney and stress the attached vessels and
concentric layers of connective tissue protect and stabilize each ureter. This condition is called a floating kidney. It may cause
kidney (Figure 26–2b): pain or other problems from the distortion of the ureter or
blood vessels during movement.
1. The fibrous capsule, a layer of collagen fibers that covers
the outer surface of the entire organ. A typical adult kidney is reddish-brown and about 10 cm
(4 in.) long, 5.5 cm (2.2 in.) wide, and 3 cm (1.2 in.) thick
2. The perinephric fat, a thick layer of adipose tissue that (Figures 26–3 and 26–4). Each kidney weighs about 150 g
surrounds the fibrous capsule. (5.25 oz). The hilum, a prominent medial indentation, is the
point of entry for the renal artery and renal nerves. The hilum is
3. The renal fascia, a dense, fibrous outer layer that anchors also the point of exit for the renal vein and the ureter.
the kidney to surrounding structures. Collagen fibers ex-
tend outward from the fibrous capsule through the peri- Sectional Anatomy of the Kidneys
nephric fat to this layer. Posteriorly, the renal fascia fuses
The fibrous capsule covering the outer surface of the kidney
also lines the renal sinus, an internal cavity within the kidney

Figure 26–3 The Gross Anatomy of the Urinary System. The abdominopelvic cavity (with the

digestive organs removed), showing the kidneys, ureters, urinary bladder, and blood supply to the urinary
structures. ATLAS: Plates 61a; 62a,b

Diaphragm Esophagus (cut) 26
Inferior vena cava Left adrenal gland

Celiac trunk Left kidney
Right adrenal gland Left renal artery
Left renal vein
Right kidney Superior mesenteric artery
Hilum
Left ureter
Quadratus lumborum Abdominal aorta
muscle
Left common iliac artery
Iliacus muscle
Psoas major muscle Gonadal artery and vein

Peritoneum (cut)
Rectum (cut)

Urinary bladder

Anterior view