Kidneys: Location and Structure

• Where do the kidneys located?

  Retroperitoneal Position
• The right kidney is slightly lower than the left.
• Renal Hilum - the kidney's medial indentation
• What are the three protective layers of the kidney?

  Fibrous Capsule, Perirenal Fat Capsule, Renal Fascia
• Fibrous Capsule - a transparent layer that encloses each kidney and gives it a glistening appearance
• Perirenal Fat Capsule - a fatty mass that surrounds each kidney and cushions it against blows
• Renal Fascia - the most superficial layer made of dense fibrous connective tissue
• Renal Fascia - layer of the kidney that anchors it and adrenal gland to surrounding structures
• What are the three distinct regions of the kidney internally?

  Renal Cortex, Renal Medulla, Renal Pelvis
• Renal Cortex - the outer region, which is light in color
• Renal Medulla - found deep to the cortex is a darker reddish brown area
• Renal Pyramids - the medulla has triangular regions with a striped appearance
• Base - the broad part of each pyramid faces toward the cortex
• Apex - the tip of each pyramid points toward the inner region of the kidney
• Renal Columns - separates the pyramids by extensions of cortex like tissue
• Renal Pelvis - located lateral to the hilum is flat, funnel-shaped tube
• Calyces - are the extensions of the pelvis, form cup-shaped "drains" that enclose the tips of the pyramids
• Calyces - collect urine, which continuously drains from the tips of the pyramids
• Renal Artery - the artery supplying each kidney with blood
• Segmental Arteries - as the renal artery approaches the hilum, it divides into this type of arteries
• Interlobar Arteries - are several branches from segmental arteries, which travel through the renal columns to reach the cortex
• Arcuate Arteries - are originated from the interlobar arteries, located at the cortex-medulla junction, which arch over the medullary pyramids
• Cortical Radiate Arteries - branch off from the arcuate arteries to supply the renal cortex
• What is the pathway of the venous blood draining from the kidney?

  Cortical Radiate Veins, Arcuate Veins, Interlobar Veins, Renal Vein
• Renal Vein - emerges from the kidney hilum and empties into the inferior vena cava