NIC Esthetician Written ExamScientific ConceptsHard
A client is interested in understanding the structural components of their skin. They ask about the protein fibers that provide strength and resilience, preventing the skin from tearing, and the fibers that allow the skin to stretch and recoil. Which pair of protein fibers, respectively, best describes these functions in the dermis?
- AActin and Myosin
- BFibronectin and Laminin
- CCollagen and Elastin
- DKeratin and Melanin
Show answer & explanationAnswer & explanation
Correct answer: C. Collagen and Elastin
Collagen fibers provide tensile strength and prevent tearing, while elastin fibers provide elasticity, allowing the skin to stretch and recoil. Both are crucial protein fibers found in the dermis.
Why the other options are wrong
- A. Actin and myosin are proteins primarily involved in muscle contraction, not the structural integrity of skin.
- B. Fibronectin and laminin are extracellular matrix glycoproteins involved in cell adhesion and migration, but not the primary fibers for skin strength and elasticity.
- D. Keratin provides structural integrity to the epidermis, hair, and nails; melanin is a pigment. Neither fits the description of dermal strength/stretch.
Dermal Connective Tissue Fibers
The two primary protein fibers in the dermis are collagen (providing strength and resistance to tearing) and elastin (providing elasticity and the ability to stretch and recoil).
- Collagen: strength, anti-tear
- Elastin: stretch, recoil
- Found in the dermis
Memory trick: Collagen is the 'Carpet' of strength, Elastin is the 'Elastic Band' of stretch.