NIC Cosmetology Written (Theory) ExamScientific ConceptsEasy
A cosmetologist is performing a facial service. They are applying a product that contains an alpha hydroxy acid (AHA) to exfoliate the client's skin. Which of the following layers of the epidermis is the outermost protective layer, composed of dead, keratinized cells, and is primarily targeted by superficial exfoliation treatments?
- AStratum Spinosum
- BStratum Lucidum
- CStratum Corneum
- DStratum Granulosum
Show answer & explanationAnswer & explanation
Correct answer: C. Stratum Corneum
The stratum corneum is the outermost layer of the epidermis, consisting of flattened, dead keratinocytes. It acts as a protective barrier and is the layer primarily removed during superficial exfoliation.
Why the other options are wrong
- A. The stratum spinosum is below the granulosum and is known for its spiny appearance due to desmosomes.
- B. The stratum lucidum is a clear layer found only in thick skin like palms and soles, not typically targeted by facial exfoliants.
- D. The stratum granulosum is where keratinization begins, and cells start to flatten and die.
Stratum Corneum
The outermost layer of the epidermis, composed of dead, flattened keratinocytes, acting as the primary protective barrier of the skin.
- Contains 15-20 layers of dead cells.
- Provides protection against environmental damage and water loss.
- Targeted by superficial exfoliation treatments.
Memory trick: Come, Let's Get Sun Burned (Corneum, Lucidum, Granulosum, Spinosum, Basale).