Final answer:
The correct answer is C) Decreased Skin Elastin, as aging leads to reduction in skin elasticity due to changes like thinner epidermis and dermis, and decreased mitosis in the stratum basale.
Step-by-step explanation:
The functional changes to the musculoskeletal (MSK) system due to aging include a loss of lean body mass, development of osteoporosis, changes in joints and cartilage, degenerative changes in the cervical spine, and loss of skin elastin and subcutaneous fat. Of the options provided, Decreased Skin Elastin corresponds with these age-related changes. Aging is associated with a decrease in the elasticity of skin due to reductions in cell division, metabolic activity, and hormonal levels which affect the skin's ability to regenerate, leading to a thinner epidermis and dermis. Sarcopenia, or the age-related atrophy of muscle tissue, and osteoporosis, the reduction of bone density, are common issues affected by genetic and environmental factors including diet, smoking, alcohol consumption, and lack of exercise. Overall, aging has a profound effect on the musculoskeletal system, leading to decreased muscle mass, bone density, joint flexibility, and overall tissue health.