Desmosomes are found in which membrane regions?

• A. Lateral and basal
• B. Apical only
• C. Basal only
• D. Lateral only

Answer: (A)

Desmosomes are cell–cell junctions that give epithelial tissues their mechanical strength by linking intermediate filaments of neighboring cells. They are located on the lateral membranes—the sides where adjacent cells touch—so the cells hold together along the length of the tissue. The basal surface, facing the basement membrane, is where structures called hemidesmosomes attach cells to the extracellular matrix, not desmosomes. The apical surface is where tight junctions and other junctions are most prominent. Therefore, desmosomes are best described as being in the lateral regions between cells, not basal.