Final answer:
Epithelial tissues have functions including protection, secretion, absorption, and excretion. They act as a barrier against damage, produce and release substances, and facilitate waste absorption and excretion.
Step-by-step explanation:
Epithelial tissues have several functions including protection, secretion, absorption, and excretion. They act as a barrier to protect the body from physical, chemical, and biological damage. For example, the outer layer of the skin is made up of epithelial tissue, which protects underlying tissues from injury, infection, and dehydration.
Epithelial tissues also have glandular functions, meaning they can produce and secrete substances. For instance, the epithelial cells in the lining of the stomach produce and release digestive enzymes and gastric acid to aid in the digestion process. In addition, epithelial tissues in the kidneys are responsible for absorption and excretion of waste materials.