Nebraska Barber State Practice Exam

Dry skin is caused by under-active sebaceous glands, not sudoriferous glands, thyroid glands, or salivary glands. The sudoriferous glands produce sweat, not oil, so they are not responsible for moisturizing the skin. The thyroid glands, which are responsible for regulating metabolism and producing hormones, do not have a direct impact on skin moisture. The salivary glands also do not contribute to skin hydration, as their main function is to produce saliva for digestion.