4-stage cross-section of the bronchus demonstrating the tissue changes occurring in asthma and chronic bronchitis. 4-stages: normal bronchus, hypersecretion of the muccous gland, swelling with lymphoid aggregations and smooth-muscle spasm. The model includes: cartilage, mucous glands and plug, spiraling smooth muscles, and the fibroeleastic connective tissue and epithelial layers of the bronchus. All stages rotate on hinge pin. Model size: (4) 1-1/2" dia. x 7/8" (3-3/4"). Card size: 6-1/2"x 5-1/4". Base size: 6-1/2"x 5"x 1