Final answer:
Cells in muscle tissue and epithelial tissue form cohesive sheets via structures like desmosomes and intercalated discs, crucial for the functionality of organs that stretch or require synchronized contractions.
Step-by-step explanation:
Cells, especially in muscle tissue, fit closely together to form cohesive sheets that are critical for proper function. In the human body, these cell sheets are held together by structures such as desmosomes, which act similarly to spot welds, connecting adjacent epithelial cells.
Desmosomes are composed of proteins like cadherins that bond to intermediate filaments within the cell, providing durability and stability in organs that require elasticity, such as the skin, heart, and various muscle types. This is particularly important in the heart, where cardiac muscle cells are connected by intercalated discs that house desmosomes and gap junctions, ensuring synchronized contractions. Furthermore, epithelial tissue forms continuous sheets made up of cells tightly packed together, which line body cavities, internal organs, and cover the body surface such as the skin.