The kidneys are two organs that belong to the urinary system.
The kidneys are located on both sides of the spine, along the posterior wall of the abdomen, below the diaphragm.
Location of kidneys
The right kidney is a little lower, due to the presence of the liver. Above the kidneys are the adrenal glands.
The kidneys are bean-shaped and reddish-brown in color. They are about 12 centimeters long and weigh up to 170 grams each.
Kidney Anatomy and Histology
Each kidney is lined with three layers of tissue: the renal fascia, the fat capsule, and the fibrous capsule.
The internal anatomy of the kidneys is divided into two zones, the cortex and the kidney medulla.
The renal cortex corresponds to the outermost layer, just after the fibrous capsule of the kidney. The cortex has a reddish color and smooth texture.
Nephrons are found in the renal cortex. The nephron is the basic functional unit of the kidney, responsible for the formation of urine. Each kidney has thousands of nephrons.
Learn more about nephron.
The renal medulla has a reddish-brown color. Basically, the medulla consists of 8 to 18 cuneiform structures, the kidney pyramids.
The kidney pyramids are groupings of ducts that collect the urine formed in the nephrons. The base of the pyramids faces the cortex and the apex faces the medulla. At the apex of each pyramid is the renal papilla.
Each papilla is surrounded by the smaller chalices that come together to form the larger chalices. From the greater renal calyx, urine drains into the renal pelvis, where all the urine produced in the kidney is released. From the renal pelvis, urine reaches the ureter until it reaches the urinary bladder.
As for the external anatomy, there is an upper region, where the suprarenal gland is located, and an inferior one. In the middle region is the hilum, a vertical cleft. From the hilum depart the renal artery, renal vein, and ureter.
kidney anatomy
Learn more about Urinary system.
Kidney Functions
The main functions of the kidneys are:
- Urine production;
- Elimination of metabolism products, such as urea and creatine;
- Regulation of body fluid volume;
- Removal of toxins from the blood;
- Blood pressure control.
Learn more, read also:
- Organs of the Human Body
- Human Body
- Urinary System Exercises
