NIC Esthetician Written ExamScientific ConceptsMedium
A client is interested in treatments to improve skin texture and reduce pore size. The esthetician explains that regular exfoliation and professional treatments can stimulate cellular renewal. Which epidermal layer is primarily responsible for producing new keratinocytes that migrate upwards to form the outer layers of the skin?
- AStratum Spinosum
- BStratum Lucidum
- CStratum Basale
- DStratum Granulosum
Show answer & explanationAnswer & explanation
Correct answer: C. Stratum Basale
The stratum basale (also known as the basal layer or stratum germinativum) is the deepest layer of the epidermis, containing stem cells that continuously divide to produce new keratinocytes.
Why the other options are wrong
- A. The stratum spinosum is characterized by desmosomes and keratinocyte maturation, but cells originating from the basale.
- B. The stratum lucidum is a clear layer found only in thick skin (palms/soles) and consists of dead, flattened cells.
- D. The stratum granulosum is involved in keratinization and lipid production, but not the primary site of cell division.
Stratum Basale
The deepest layer of the epidermis, consisting of a single layer of cuboidal or columnar cells that undergo continuous cell division to produce new keratinocytes.
- Deepest epidermal layer
- Site of keratinocyte stem cells
- Continuous cell division (mitosis)
Memory trick: The 'Basale' is the 'Base' where new cells are born.