NIC Nail Technician Written ExamScientific ConceptsMedium
The stratum corneum is the outermost layer of the epidermis. What is its primary function in relation to the skin's overall protective role?
- ATo provide strength and flexibility to the skin.
- BTo act as a waterproof barrier against environmental damage and dehydration.
- CTo produce melanin for UV protection.
- DTo initiate immune responses against foreign invaders.
Show answer & explanationAnswer & explanation
Correct answer: B. To act as a waterproof barrier against environmental damage and dehydration.
The stratum corneum consists of dead, flattened keratinocytes embedded in a lipid matrix, forming a tough, waterproof barrier that protects the body from desiccation, chemical irritants, and microbial invasion.
Why the other options are wrong
- A. Strength and flexibility are provided by the dermis and deeper epidermal layers, not primarily the dead cells of the stratum corneum.
- C. Melanin production occurs in the stratum basale (melanocytes), not the stratum corneum.
- D. Immune responses are primarily initiated by Langerhans cells in the stratum spinosum and other immune cells in deeper layers.
Stratum Corneum Function
The outermost layer of the epidermis, acting as the primary protective barrier against environmental damage, pathogens, and water loss.
- Composed of dead keratinocytes.
- Forms a waterproof barrier.
- Protects against abrasion and chemical entry.
Memory trick: Corneum: 'Corn'ers the market on protection.