Final answer:
The kidney tubules are lined with simple cuboidal epithelium which consists of a single layer of cube-shaped cells that are involved in secretion and absorption.
Step-by-step explanation:
Kidney tubules are composed of simple cuboidal epithelium. This type of epithelial tissue consists of a single layer of cube-shaped cells that promote secretion and absorption in ducts and tubules. The simple cuboidal epithelia are found lining the walls of kidney tubules, where they play a crucial role in the process of filtering the blood. The cells in the simple cuboidal epithelium usually have their nucleus located centrally. These cube-shaped cells are also present in the smallest duct glands in addition to kidney tubules. In the context of kidney structure, they are involved in functions essential for the kidney's role in maintaining homeostasis, including secretion and reabsorption of various substances.