Question

As a student in an esthetic program, Hannah is tasked with building a three-dimensional model of the layers of the skin. Her model must include captions describing each skin layer and connect skin histology and physiology to esthetics.

Hannah's aunt has been diagnosed with melanoma; therefore, she is interested in how the skin protects itself from the sun. She includes in her notes that in the stratum germinativum, melanocytes produce the pigment _____ in response to DNA damage.*

a) Melanin
b) Carotene
c) Hemoglobin
d) Collagen

Answer 1

Melanocytes in the stratum germinativum produce the pigment melanin in response to DNA damage from UV light, which helps protect the skin by absorbing UV radiation.

Step-by-step explanation:

In response to DNA damage from exposure to UV light, melanocytes in the stratum germinativum (also known as the stratum basale) produce the pigment melanin. Melanin's primary function is to absorb UV light and protect underlying cells from UV damage. It is transferred into the keratinocytes via a cellular vesicle called a melanosome. This action is a defense mechanism of the skin against the harmful effects of the sun. Melanocytes are distributed throughout the stratum basale layer of the epidermis and upon stimulation, increase melanin production.

This process is responsible for the tanning of the skin, as well as the natural skin pigmentation which varies among individuals. The more melanin present in the skin, the greater the protection against UV-induced damage, such as the development of skin cancers like melanoma. In contrast, other pigments like carotene and hemoglobin also contribute to skin color but are not involved in response to DNA damage due to UV light.