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LSS Urinary System

Alexandra Burke-Smith

Blood supply  Arterial – from renal arteries which branch directly from the abdominal aorta (lies posterior to the left renal vein) o These arteries are short, fat therefore receive a good blood supply at HIGH pressure (this high pressure drives the ultrafiltration process by glomerular capillaries) o Renal arteries branch profusely into arcuate arteries which supply each glomerulus  Venous – renal vein from each kidney drain directly into the IVC Structure  Each kidney is surrounded by a deep dense fibrous capsule, a middle adipose capsule and a superficial renal fascia o Clinical correlate: kidney infection/absess – pressure builds up within the capsule which leads to a reduced blood supply and risk of necrosis. Treatment involves needle insertion + drainage from capsule  each kidney consists of a superior + inferior pole, and can be described as segmental/multilobular  frontal section through kidney reveals two distinct regions: a granular looking cortex + an inner striated medulla  The renal medulla consists of several cone-shaped renal pyramids. The base of each pyramid faces the renal cortex, and its apex (called the renal papilla) points towards the renal hilum  The granular-looking renal cortex extends from the renal capsule to the bases of each renal pyramid, forming renal columns between each pyramid  A renal lobe consists of a renal pyramid, its overlying area of renal cortex, and ½ of each adjacent renal column  Together, the renal cortex + renal pyramids constitute the parenchyma of the kidney (functional portion), with associated functional units called nephrons. o The cortex + medulla each contain distinct parts of the nephrons, with the cortex consisting of the glomeruli surrounded by the convoluted tubules, and the medulla containing loops of Henle (in parallel bundles – gives striated appearance) o Urine formed by the nephrons drain into large papillary ducts which extends through the renal papilla (involved in making urine concentrated) o The papilla then drain into cuplike structures called minor + major calyces o Each minor calyx receives urine from the papillary ducts of one renal papilla, and delivers it to a major calyx o From the major calyx, urine is drained into a single large cavity called the renal pelvis, then out through the ureter to the urinary bladder 2

Alex's Urinary  

Alex's Urinary