Final answer:
The stratum corneum, being the most superficial layer of the epidermis, is primarily responsible for preventing the entry of pathogens. Due to increased keratinization and several layers of cells, it serves as a barrier against microbes and the dehydration of underlying tissues. It also provides mechanical protection against abrasion.
Step-by-step explanation:
The function of preventing the entry of pathogens is attributed to the stratum corneum. This is the most superficial layer of the epidermis, thus making it the first point of contact with the external environment. Comprising of 15 to 30 layers of cells, the stratum corneum has increased keratinization of cells which serve as a barrier that prevents the penetration of microbes and the dehydration of tissues lying beneath.
Moreover, it is known for providing mechanical protection against abrasion. The cells in this layer are periodically shed off, and subsequently replaced by new ones pushed up from the stratum granulosum. This constant renewal of cells, about every 4 weeks, keeps the skin 'fresh' and healthy.
The subcutaneous tissue and the stratum germinativum have important roles in the skin, but the primary function of preventing the entry of pathogens is carried out by the stratum corneum.
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