Final answer:
The term for long, rectangular-shaped epithelial cells is 'columnar epithelial cells'. They are taller than wide and commonly found in a simple epithelium arrangement. These cells function in absorption and are present in the digestive tract and reproductive system.
Step-by-step explanation:
Classification of Epithelial Tissues
Epithelial tissues are primarily classified based on two characteristics: the shape of the cells and the number of cell layers they form. One cell shape that we encounter in epithelial tissues is columnar, in which the cells are shaped like long rectangles and are taller than they are wide. These columnar epithelial cells are often found in a single-layer arrangement, known as a simple epithelium.
Particularly, in the digestive tract, columnar epithelial cells play a crucial role in absorption. They have nuclei aligned at the base of the cell, which is a structure helpful in their function. These cells are specialized to absorb nutrients and other substances from the lumen of the digestive tract, moving them into the circulatory and lymphatic systems. Goblet cells scattered throughout release mucus to protect and lubricate the luminal surface, while microvilli increase the surface area for more efficient absorption.
Furthermore, the simple columnar epithelium not only lines parts of the digestive system but is also present in sections of the female reproductive tract. Some of these columnar epithelia possess cilia, which help move particles along the luminal surface, as seen in the fallopian tubes and parts of the respiratory tract.