Explain the structure of kidney.

Kidneys are bean-shaped organs located in the left and right of vertebrae column backside below stomach. Each kidney is enclosed in a renal capsule which is surrounded by the adipose tissue. Internally the kidney has the following parts- renal cortex, renal medulla, renal pyramids, renal columns and renal pelvis along with major and minor calyces. Kidney is the main excretory organ of excretion that release about 80% of liquid waste from the body. Blood enters the kidney through renal artery and leaves the kidney through renal vein.