This document provides an overview of various diseases that affect different body systems, including the integumentary, skeletal, muscular, nervous, and circulatory systems. For each system, it describes two representative diseases, their causes, symptoms, and potential treatments. The integumentary diseases covered are albinism and herpes, the skeletal diseases are osteochondroma and osteoarthritis, the muscular diseases are tendonitis and PCL injury, the nervous diseases are Alzheimer's disease and Parkinson's disease, and the circulatory diseases are peripheral vascular disease and congenital heart defect.