4 Pc Bronchus
Four stage cross-section of the bronchus demonstrating the tissue changes occurring in asthma and chronic bronchitis.
Four stages: normal bronchus, hypersecretion of the mucous gland, swelling with lymphoid aggregations and smooth-muscle spasm.
The model includes: cartilage, mucous glands and plug, spiraling smooth muscles, and the fibroelastic connective tissue and epithelial layers of the bronchus.
All stages rotate on hinge pin.