Quick Answer: Human Lung Model in Bell Jar shows how the lungs fill and empty as the diaphragm muscle contracts and relaxes, using two balloons on a Y-tube as the lungs inside a bell jar, with a stout rubber sheet as the diaphragm.
Last updated: October 2026
Key Features
Two balloons attached to a Y-tube act as the lungs
Bell jar, open at the upper end, acts as the chest cavity
Stout rubber sheet acts as the diaphragm
Pulling the sheet down lowers the pressure inside, so the lungs expand and take in air
Releasing the sheet lets the lungs deflate
Technical Specifications
Specification
Value
Chest cavity
Bell jar, open at the upper end
Lungs
Two balloons attached to a Y-tube
Diaphragm
Stout rubber sheet
About This Product
Students pull the rubber sheet downward, which lowers the atmospheric pressure inside the jar so the balloons expand and draw in air; when it is released, they deflate. Among the Human System Model items, it is the working demonstration of breathing rather than a display of lung anatomy.
Frequently Asked Questions
Q1. What acts as the diaphragm in the bell jar model? A stout rubber sheet on the bell jar acts as the diaphragm.
Q2. Why do the balloons inflate when the sheet is pulled down? Pulling the diaphragm downward lowers the pressure inside the chamber, so the lungs expand and take in air. When it is released, the lungs deflate.
Lab Equipments Ambala supplies institutions and distributors in Seychelles, Saudi Arabia and Côte d'Ivoire, as part of its export work to 80+ countries.
