In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin?The cells of the epidermis store glucose as glycogen for energy. It aids in the transport of materials throughout the body. It converts modified epidermal cholesterol to a vitamin D precursor important to calcium metabolism. It absorbs vitamin C so that the skin will not be subject to diseases.

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.