NIC Nail Technician Written ExamScientific ConceptsMedium

The stratum corneum is the outermost layer of the epidermis. What is its primary function in relation to nail health and overall skin protection?

  1. ATo provide a waterproof barrier against external threats.
  2. BTo produce melanin for skin pigmentation.
  3. CTo generate new skin cells through mitosis.
  4. DTo house nerve endings for sensory perception.
Show answer & explanation

Correct answer: A. To provide a waterproof barrier against external threats.

The stratum corneum consists of dead, flattened cells filled with keratin, forming a tough, protective layer that prevents water loss and acts as a barrier against pathogens and environmental damage.

Why the other options are wrong

  • B. Melanin production occurs in the stratum basale (melanocytes).
  • C. New skin cells are generated in the stratum basale (germinativum).
  • D. Nerve endings are primarily found in the dermis and deeper epidermal layers.

Stratum Corneum

The outermost layer of the epidermis, composed of dead, flattened keratinocytes, forming a protective, waterproof barrier for the body.

  • Composed of dead skin cells (corneocytes).
  • Provides protection against dehydration, abrasion, and microbes.
  • Continuously sheds and is replaced from deeper layers.

Memory trick: Corneum is like a 'corn'erstone, protecting from all sides.

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