Final answer:
Hypopigmentation refers to a decrease in skin pigmentation, leading to lighter colored patches, observed in conditions like vitiligo. Hyperpigmentation, like that seen in untreated Addison's disease, increases skin pigmentation. The tanning response is protective against UV radiation, but excessive exposure can still lead to skin damage and aging effects on the skin are evident in the integumentary system.
Step-by-step explanation:
The level of response of hypopigmentation can vary, but it generally refers to the decreased pigmentation in the skin compared to normal levels, leading to lighter colored patches of skin. Conditions such as vitiligo are characterized by hypopigmentation, where individuals develop lighter patches as melanocytes, the cells responsible for skin pigmentation, are destroyed or cease to function properly. In contrast, hyperpigmentation is an increase in skin pigmentation, which is apparent in conditions like Addison's disease before treatment.
The body's defense against skin damage from UV radiation is reflected in the tanning response, in which pigments are produced to absorb UV radiation, protecting living cells beneath the inert skin layers. It is important to note that while the tanning response is a protective mechanism, excessive exposure to UV-B can lead to skin damage such as sunburn and increase the risk of developing skin cancer.
As we age, our skin undergoes various changes reflected in systems like the integumentary system. These changes include decreased cell division and metabolic activity, leading to a thinner epidermis, reduced elasticity and resilience in the dermis, and changes in the hypodermis resulting in the thinning and sagging of the skin.