CLS Skin Anatomy and Fitzpatrick Scale

Question 1

The epidermis is divided into five layers. Which layer is directly responsible for producing new skin cells through mitosis?

Accepted Answer

Stratum basale

Answer

Stratum corneum

Answer

Stratum granulosum

Answer

Stratum spinosum

Question 2

What is the primary function of melanin in skin?

Accepted Answer

Absorbing and dissipating UV radiation to protect underlying cells from DNA damage

Answer

Providing structural support to the dermal collagen matrix

Answer

Regulating transepidermal water loss through the stratum corneum

Answer

Triggering the inflammatory cascade in response to bacterial invasion

Question 3

Which Fitzpatrick skin type is characterized by skin that 'always burns, never tans' and is associated with the highest risk of UV-induced damage?

Accepted Answer

Type I

Answer

Type III

Answer

Type IV

Answer

Type II

Question 4

Where are hair follicles located anatomically, and why does this matter for laser hair removal?

Accepted Answer

Rooted in the dermis (bulb in the deep dermis, bulge in the mid-dermis); laser must penetrate to dermal depth to destroy the follicle

Answer

Entirely in the epidermis; laser energy need only penetrate the epidermis

Answer

Located in the hypodermis; only ablative lasers can reach them

Answer

Attached to sweat glands in the upper epidermis

Question 5

Which statement correctly describes the difference between eumelanin and pheomelanin?

Accepted Answer

Eumelanin is brown-black and absorbs laser energy efficiently; pheomelanin is yellow-red, found in red and blonde hair, and absorbs laser energy less efficiently

Answer

Eumelanin is yellow-red and found predominantly in light hair; pheomelanin is dark brown-black and found in dark hair and skin

Answer

Both types absorb laser energy equally at all wavelengths

Answer

Pheomelanin is produced by keratinocytes; eumelanin is produced by fibroblasts

Question 6

A patient is Fitzpatrick type IV. What clinical characteristics define this skin type?

Accepted Answer

Light brown skin, sometimes burns, tans easily and darkens significantly

Answer

Fair skin, burns easily, tans minimally

Answer

Medium skin (light brown to olive), rarely burns, always tans well

Answer

Dark brown skin, never burns, tans profusely