The kidneys are located in the back of the abdominal cavity, one on the left and one on the right side of your spine. The left one is usually larger than the right, as the right kidney often shares space with the liver. Kidneys are covered with two thick layers of fat for protection and one thin layer of microfibers that create a renal capsule or covering. On the top of each kidney sits an adrenal gland that helps connect the kidneys to other organs.
Kidneys contain multiple lobes that are shaped in the form of small pyramids. Consequently, each lobe consists of its own renal cortex (outer section) and medulla (inner section). The space between these elements is filled with nephrons (smallest single unit of the kidneys) that are responsible for the creation of urine. The urine runs through thin tubes called the ureters to reach the bladder, while blood passes through the renal arteries and drains back to the renal veins.