Representative histological images of the longitudinal (left panels) and transverse (right panels) sections of four TA specimens from different age groups. Aortas are from (A) 14-year-old, (B) 31-year-old, (C) 51-year-old and (D) 73-year-old subjects. In young TA samples, the elastic lamellae are thick, undulated, and are located close to each other, while the opposite is observed for old TAs. Verhoeff-Van Gieson (VVG) stain: elastin is black, collagen is red, smooth muscle is brown.