Lung
stub — Seeded as a structural anchor for the respiratory-system; not yet written out.
The lung is the gas-exchange organ. Lung aging features declining elastic recoil, airspace enlargement (“senile emphysema”), impaired mucociliary clearance, and a prominent cellular-senescence component — idiopathic pulmonary fibrosis (IPF) is one of the canonical senescence-driven age-related diseases, driven by alveolar epithelial (AT2) and fibroblast senescence, and a frequent target of senolytic research (senolytics).