Illustration of lung sections infected with tuberculosis. Tuberculosis (TB) is a bacterial infection that usually affects the lungs but can affect other body tissues. It causes inflammation and scarring in the lungs, leading to tissue damage. Here, a lung section (top) contains the remains of an abscess that has formed a scar filled with a thick substance. Another lung section (bottom) shows a severely inflamed bronchial mucous membrane with small ulcerations (white), indicative of bronchitis. The bronchial glands (black) are also enlarged and contain several chalky nodules (white). Commonly called commonly in the 1800s, TB was a widespread cause of death during this period before the invention of vaccines (1921) and antibiotics (1943). Published in 'Illustrations of pulmonary consumption' by Samuel George Morton in 1834.