The two kidneys of the human body are located in a retroperitoneal location, each on one side of the spine. The left kidney sits slightly higher than the right kidney, and the left kidney sits slightly closer to the spine that the right. Kidneys can move a few centimeters, and they move regularly with respiration. They are surrounded by and moved by the psoas major, quadratus lumborum, and transverse abdominis muscles. Kidneys are approximately fist-sized and weigh about five ounces. They are partially protected by the rib cage. The adrenal glands sit immediately to the top of the kidneys.
Kidneys are bean-shaped; the concave area is referred to as the hilum. The hilum is situated to face the spine. This is the area where the ureter exits the kidney. There are also nerves, many blood vessels, and some lymph vessels in this area. Specifically, the renal artery, and the renal vein enter the kidney here. These vessels and the kidney itself are surrounded by perirenal fat. This fat also spreads to the renal sinus.
The entire kidney itself is enclosed in three layers of tissue. The renal capsule is made of connective tissue and it protects the kidney from diseases and infections as well as trauma (Kidney Anatomy, 2017). It also helps the kidneys maintain their shape. Interior to the renal capsule is a layer of adipose tissue. This fatty capsule helps to secure the kidney in the abdominal cavity and it also buffers it from physical trauma. This layer is dense and irregular tissue, and it also helps the kidneys maintain their shape. The innermost layer of tissue surrounding the kidney is the renal facia. It is connective tissue “that anchors the kidney to the surrounding structures and to the abdominal wall” (Tortoria & Derrickson, 2013). This facia keeps the kidneys in a retroperitoneal position.
- Kidney anatomy. (2017). Kidney Chat. Retrieved from http://www.kidneychat.com/kidney-anatomy.html
- Tortoria, G.T. & Derrickson, B. (2013). Principles of anatomy & physiology. Hoboken, NJ: Wiley.
