Final answer:
The symptoms described are indicative of the natural ageing process of the skin, which involves various systemic changes leading to thinner skin, less elasticity, and slower wound healing.
Step-by-step explanation:
The signs of loss of resilience, elasticity, and strength, along with sagging skin, dryness, itching, and brown ageing spots are indicative of the natural ageing process of the integumentary system. These symptoms are associated with reductions in cell division, metabolic activity, and hormonal levels, leading to decreased mitosis in the stratum basale, thinner epidermis, and reduced elasticity in the dermis. This results in slower wound healing and the thinning and sagging of skin, as well as other changes like wrinkles, which occur due to decreased collagen and elastin production.