Left kidney sits behind the spleen.
Right kidney sits behind the liver and is slightly lower than the left.
Each kidney is enclosed in a tough fibrous capsule and is supported and protected by fat tissue. Hilus - fissure in the central concave portion of the kidney where blood vessels enter and leave. Ureters - enter at the hilus, connect the kidney to the bladder. The free ends of the pyramids form a papilla, which opens into the renal pelvis. The renal pelvis is made up of calyces, which drain the upper and lower haves of the kidney.