KIDNEY Shape & Size ▸ Kidneys are reddish brown, bean shaped structures. ▸ Situated between the levels of last thoracic and third lumbar vertebra close to the dorsal inner wall of the abdominal cavity. ▸ Each kidney of an adult human measures 10-12 cm in length, 5-7 cm in width, 2-3 cm in thickness with an average weight of 120-170 g. ► Inner to the hilum is a broad funnel shaped space called the renal pelvis with projections called calyces. ► The outer layer of kidney is a tough capsule. ► Inside the kidney, there are two zones, an outer cortex and an inner medulla. ► The medulla is divided into a few conical masses (medullary pyramids) projecting into the calyces (sing.: calyx). ► The cortex extends in between the medullary pyramids as renal columns called Columns of Bertini.