By Maggie Hira | Updated Mar 24, 2022

General Overview

The lungs are the central organ of the respiratory system, housed within the chest cavity. Their primary role is to deliver oxygen to the bloodstream while expelling carbon dioxide. This exchange occurs in the alveoli—tiny, highly porous air sacs that provide an extensive surface area for gas diffusion. Because of this intricate architecture, the lungs are large yet remarkably efficient.

Why Lungs Feel Spongy

It is the millions of alveoli that give the lungs a spongy texture. Each alveolus contains microscopic pores that allow oxygen and carbon dioxide to pass freely. The collective porous network mirrors the structure of a natural sponge, making the lungs feel soft and sponge‑like when palpated. The expansive surface area—over 70 square meters in a healthy adult—facilitates rapid gas exchange and contributes to this distinctive feel.

Warnings

The delicate nature of lung tissue means it can be easily compromised. Smoking remains the leading cause of lung damage, contributing to chronic conditions such as emphysema and lung cancer. Other major threats include:

• Cystic fibrosis – thick, sticky mucus obstructs airways.
• Pneumonia – bacterial, viral, or fungal infections inflame lung tissue.
• Tuberculosis – a bacterial disease that destroys lung tissue.
• Emphysema – enlargement of airspaces leading to reduced elasticity.
• Asthma – narrowing of bronchioles that impedes airflow.

Protecting lung health through cessation of smoking, vaccination, and regular check‑ups can significantly reduce the risk of these diseases.