Which statement about the epidermis, according to the material, is true?

Which statement about the epidermis, according to the material, is true?

• A. The epidermis provides good resistance to chemicals
• B. The epidermis contains nerves close to the surface to sense touch
• C. The epidermis is not involved in immune defense
• D. The epidermis has abundant blood vessels

Answer: (A)

The epidermis serves as a strong barrier to chemical exposure. Its outermost layer, the stratum corneum, is made of dead, flattened keratinocytes embedded in a lipid-rich matrix, creating a dense, waterproof shield that greatly slows or prevents chemical penetration. The epidermis is also avascular, so substances don’t readily move into the bloodstream through this layer, which further reduces absorption. Nerves aren’t close to the surface in the epidermis; sensation comes from nerve endings in the underlying dermis. The epidermis does participate in immune defense via cells like Langerhans cells, so it is involved in immune responses. Finally, the epidermis lacks abundant blood vessels, with vascular supply located in the dermis. Thus the statement that the epidermis provides good resistance to chemicals is true.

The epidermis serves as a strong barrier to chemical exposure. Its outermost layer, the stratum corneum, is made of dead, flattened keratinocytes embedded in a lipid-rich matrix, creating a dense, waterproof shield that greatly slows or prevents chemical penetration. The epidermis is also avascular, so substances don’t readily move into the bloodstream through this layer, which further reduces absorption.

Nerves aren’t close to the surface in the epidermis; sensation comes from nerve endings in the underlying dermis. The epidermis does participate in immune defense via cells like Langerhans cells, so it is involved in immune responses. Finally, the epidermis lacks abundant blood vessels, with vascular supply located in the dermis.

Thus the statement that the epidermis provides good resistance to chemicals is true.