This course is the last in the continuum of the organ system approach to the study of human disease presented in PATHD 1601 and PATHD 1602. The causes and pathophysiologic mechanisms underlying diseases of specific organ systems are examined along with their cytological, histological, and somatic manifestations. The pathophysiologic derangements of these diseases and potential consequences for the patient are also examined. The relationships between organ system diseases and ultimate systemic manifestations/implications are analyzed. Osteopathic principles and theory are incorporated into these studies, along with clinical case-based exercises.