In the kidney, simple cubodial epithelium tissue forms the tubules. Cubodial tissue is classified as simple, since it consists of only a single layer of cells, as reported by the University of Michigan Medical School.
The kidneys are vital organs that filter waste, removing it as urine, and are a part of the sophisticated urinary system. The human body has two kidneys, that, according to WebMD, contain about one million tiny nephrons, each made up of a filter that is attached to a tubule.
In the process of filtration, the kidneys retain as much water, sugars and salts as possible while filtering out the waste products, such as urea, states the Kidney & Urology Foundation of America. The tubules, often referred to as the renal tubules, reabsorb the beneficial solutes and water back into the body while continuing the filtration of the waste during its journey to the bladder.