Final answer:
The structures found in simple epithelial tissues are squamous, cuboidal, and columnar cells, which form a single layer attached to the basal lamina and specialize in functions such as protection, secretion, and absorption.
Step-by-step explanation:
Epithelial tissue, also known as epithelium, is a group of cells forming the outer layer of the body and lining internal surfaces and cavities. It is essential for functions such as protection, secretion, absorption, and filtration. When we talk about simple epithelial tissue, we are referring to a single layer of cells adhering to the basement membrane or basal lamina. The cells in simple epithelial tissues can be of various shapes;
- Squamous: These cells are flat and thin, resembling a tiled floor when viewed from above, and are found in places where rapid diffusion is necessary, such as the walls of capillaries and alveoli of the lungs.
- Cuboidal: As the name suggests, these cells are cube-like and are often found lining glands and ducts, such as those in the kidney and liver, where their function includes secretion and absorption.
- Columnar: These cells are taller than they are wide, much like columns, and are present in areas like the lining of the stomach and intestines, where the cells absorb nutrients and produce mucus.
It is important to note that while all these cell shapes can be found in simple epithelia, meaning they are arranged in a single layer, these cell types can also be arranged in layers to form stratified epithelia for added protection and durability in certain parts of the body. Furthermore, there are specialized epithelial tissue types, such as pseudostratified and transitional epithelium.