ANATOMY

Detailed explanation-1: -The oldest epidermal cells in the epidermis are found in the stratum basale.

Detailed explanation-2: -The stratum corneum is the outermost layer of the epidermis, and is made up of 10 to 30 thin layers of continually shedding, dead keratinocytes.

Detailed explanation-3: -It is composed primarily of keratinocytes (95%), with the remainder being Langerhans cells, melanocytes, and Merkel cells. Keratinocytes arise from the stratum basale and undergo progressive differentiation whilst migrating toward the stratum corneum (Benson et al., 2019).

Detailed explanation-4: -The human stratum corneum comprises several levels of flattened corneocytes that are divided into two layers: the stratum disjunctum and stratum compactum. The skin’s protective acid mantle and lipid barrier sit on top of the stratum disjunctum. The stratum disjunctum is the uppermost and loosest layer of skin.

Detailed explanation-5: -Answer and Explanation: Keratinocytes form in the hypodermis, the lowest layer of our skin. This means we find the youngest keratinocyte cells in the hypodermis.