Layers of Skin Quiz

Layers of Skin

• Stratum Corneum:

  • Outermost layer consisting of dead, flattened cells without nuclei.
  • Primarily found on palms and soles, providing protection.

• Stratum Lucidum:

  • A thin layer found only in specific areas such as palms and soles.
  • Contains refractile granules of eleidin, contributing to skin resilience.

• Stratum Granulosum:

  • Characterized by keratohyalin granules that produce filaggrin, essential for skin hydration.
  • Contains lamellar granules (Odland bodies) that secrete lipids, helping in skin barrier formation.

• Stratum Spinosum:

  • Rich in desmosomes, which facilitate the attachment of keratinocytes for structural integrity.
  • Key site for keratin synthesis, contributing to skin strength.
  • Highly mitotically active, promoting proliferation of skin cells.

• Stratum Basale (Stratum Germinativum):

  • Innermost layer where active mitosis occurs, leading to generation of new keratinocytes.
  • Site of attachment to the basement membrane and essential for epidermal regeneration.

Epidermal Turnover Time (ETT) / Skin Doubling Time

• Refers to the duration required for keratinocytes to migrate from the stratum Basale to shedding in the environment.
• Average ETT is approximately 8 weeks (42 – 75 days).
• In conditions like psoriasis, epidermal turnover is significantly expedited, occurring within just 4 days.