Editing Kidneys (section)

=== Venous drainage ===
* '''Correlates closely with the arterial supply, with the exception that venous drainage has extensive collateral communication. unlike the arterial supply'''
* 3-5 segmental renal veins eventually unite to form the renal vein
* '''The right and left renal veins lie anterior to the right and left renal arteries and drain into the IVC.'''
* '''<span style="color:#ff0000">The right renal vein is 2-4 cm, the left renal vein is 6-10 cm.</span>'''
* '''<span style="color:#ff0000">The longer left renal vein receives the left adrenal vein and the left gonadal (testicular or ovarian) vein.</span>''' 
**'''<span style="color:#ff0000">The left renal vein also may receive a lumbar vein,</span> which could be easily avulsed during surgical manipulation of the left renal vein.'''
* '''The left renal vein traverses the acute angle between the superior mesenteric artery anteriorly'''
** '''Nutcracker syndrome most often refers to compression of the left renal vein between the superior mesenteric artery and aorta'''
** Insert figure
** '''Anomalies of the renal veins are less common than those of the renal arteries'''