So when u see this picture, u might wonder; Whats a kidney??? :3 i took my time to explain!

In humans, the kidneys are located behind the abdominal cavity, in a space called the retroperitoneum. There are two, one on each side of the spine; they are approximately at the vertebral level T12 to L3.[2] The right kidney sits just below the diaphragm and posterior to the liver, the left below the diaphragm and posterior to the spleen. Resting on top of each kidney is an adrenal gland (also called the suprarenal gland). The asymmetry within the abdominal cavity caused by the liver typically results in the right kidney being slightly lower than the left, and left kidney being located slightly more medial than the right.[3][4] The upper (cranial) parts of the kidneys are partially protected by the eleventh and twelfth ribs, and each whole kidney and adrenal gland are surrounded by two layers of fat (the perirenal and pararenal fat) and the renal fascia. Each adult kidney weighs between 125 and 170 g in males and between 115 and 155 g in females.[2] The left kidney is typically slightly larger than the right.[citation needed]
[edit]Structure

1. Renal pyramid Ãf¢EUÃ'¢ 2. Interlobar artery Ãf¢EUÃ'¢ 3. Renal artery Ãf¢EUÃ'¢ 4. Renal vein Ãf¢EUÃ'¢ 5. Renal hilum Ãf¢EUÃ'¢ 6. Renal pelvis Ãf¢EUÃ'¢ 7. Ureter Ãf¢EUÃ'¢ 8. Minor calyx Ãf¢EUÃ'¢ 9. Renal capsule Ãf¢EUÃ'¢ 10. Inferior renal capsule Ãf¢EUÃ'¢ 11. Superior renal capsule Ãf¢EUÃ'¢ 12. Interlobar vein Ãf¢EUÃ'¢ 13. Nephron Ãf¢EUÃ'¢ 14. Minor calyx Ãf¢EUÃ'¢ 15. Major calyx Ãf¢EUÃ'¢ 16. Renal papilla Ãf¢EUÃ'¢ 17. Renal column
Bean-shaped structures, each kidney has concave and convex surfaces. The concave surface, the renal hilum, is the point at which the renal artery enters the organ, and the renal vein and ureter leaves. The kidney is surrounded by tough fibrous tissue, the renal capsule, which is itself surrounded by perinephric fat, renal fascia (of Gerota), and paranephric fat. The anterior (front) border of these tissues is the peritoneum, while the posterior (rear) border is the transversalis fascia.
The substance, or parenchyma, of the kidney is divided into two major structures: superficial is the renal cort.. :D