Question

complete each sentence by selecting the proper word or phrase from each drop - down.

1. the (click to select) is made up of multiple layers of dead keratinocytes that regularly exfoliate.
2. the next layer is the (click to select), which is present only on the soles of the feet, hands, fingers, and toes.
3. the (click to select) is named for the presence of dark staining keratohyalin granules which bind the cytoskeletal keratin filaments together.
4. towards the apical surface, in the (click to select), the keratinocytes cease cell division, while at the deeper regions, they can still undergo mitosis.
5. comprised of viable, cuboidal and columnar cells, the (click to select) contains the keratinocyte stem cells that replenish the exfoliated cells at the surface.

(click to select)
stratum basale
stratum lucidum
stratum spinosum
stratum granulosum
stratum corneum

Explanation:

1. The stratum corneum is the outermost layer of the epidermis, consisting of dead, keratin - filled cells that are shed regularly.
2. The stratum lucidum is a clear, thin layer present only in thick skin areas like the soles of feet and palms of hands.
3. The stratum granulosum contains keratohyalin granules which contribute to keratin filament aggregation.
4. In the stratum spinosum, keratinocytes near the surface stop dividing while deeper ones can still undergo mitosis.
5. The stratum basale is the innermost layer of the epidermis with viable cuboidal and columnar cells including keratinocyte stem cells.

Answer:

1. stratum corneum
2. stratum lucidum
3. stratum granulosum
4. stratum spinosum
5. stratum basale