Which layer of skin is thickest on the palms of the hands and soles of the feet?

• A. Stratum basale
• B. Stratum corneum
• C. Stratum lucidum
• D. Stratum granulosum

Answer: (C)

The thickest layer of skin on the palms of the hands and the soles of the feet is the stratum corneum. This layer is composed of dead keratinized cells that provide a protective barrier against environmental damage, including abrasion and water loss. The stratum corneum is particularly thick in areas of high friction, which is essential for protecting these areas from wear and tear.

In the palms and soles, the increased thickness of the stratum corneum is an adaptation to the mechanical stress experienced in these high-use areas. The presence of a stratum lucidum, which is only found in thick skin such as that on the palms and soles, provides additional protection but does not contribute to thickness in the same way the stratum corneum does.

While the stratum basale and stratum granulosum are important layers involved in cell proliferation and keratinization, they do not have the same role in providing the thickness seen in the stratum corneum in these regions, making the stratum corneum the correct answer.