CLT Skin Anatomy & Physiology 2 — Questions and Answers
Question 1: Which skin appendage is the primary target when performing laser hair removal?
- Eccrine sweat gland
- Hair follicle bulge and bulb (Correct answer)
- Sebaceous gland duct
- Meissner's corpuscle
Correct answer: Hair follicle bulge and bulb
Laser hair removal targets the hair follicle bulge (stem cells) and bulb (matrix cells) where melanin absorbs laser energy to destroy the follicle.
Question 2: The Fitzpatrick skin type scale classifies skin primarily based on which characteristic?
- Sebum production level
- Epidermal thickness
- Reaction to UV exposure and tanning ability (Correct answer)
- Density of melanocytes
Correct answer: Reaction to UV exposure and tanning ability
The Fitzpatrick scale (Types I–VI) classifies skin by its response to UV exposure, specifically burning and tanning tendency.
Question 3: What is the name of the water-insoluble protein that makes up the bulk of the epidermis?
- Collagen
- Elastin
- Keratin (Correct answer)
- Fibronectin
Correct answer: Keratin
Keratin is the fibrous structural protein produced by keratinocytes that provides the epidermis with its protective barrier properties.
Question 4: Which layer of the dermis contains the densely packed collagen bundles that give skin its tensile strength?
- Papillary dermis
- Reticular dermis (Correct answer)
- Stratum basale
- Hypodermis
Correct answer: Reticular dermis
The reticular dermis is the deeper, thicker layer containing coarse, interwoven collagen bundles (primarily Type I) that provide tensile strength.
Question 5: Arrector pili muscles are responsible for which physiological response?
- Regulating eccrine sweat output
- Producing sebum secretion
- Causing hair to stand erect (goosebumps) (Correct answer)
- Constricting dermal blood vessels
Correct answer: Causing hair to stand erect (goosebumps)
Arrector pili are smooth muscles attached to hair follicles; their contraction in response to cold or fear produces piloerection (goosebumps).
Question 6: In the context of selective photothermolysis, the term 'chromophore' refers to:
- The laser wavelength in nanometers
- The target molecule that absorbs laser energy (Correct answer)
- The cooling device used during treatment
- The depth of laser penetration
Correct answer: The target molecule that absorbs laser energy
A chromophore is the target molecule (e.g., melanin, oxyhemoglobin, water) that selectively absorbs specific laser wavelengths, converting light to heat.
Question 7: Which type of collagen predominates in the papillary dermis and is associated with fine, immature fibers?
- Type I collagen
- Type II collagen
- Type III collagen (Correct answer)
- Type IV collagen
Correct answer: Type III collagen
Type III collagen (reticulin fibers) predominates in the papillary dermis and is also found in wound healing and fetal skin.
CLT Skin Anatomy & Physiology 2
Which skin appendage is the primary target when performing laser hair removal?