Due to increasing air-borne allergens and pollutants, many people in urban areas are suffering from respiratory disorder causing wheezing due to

inflammation of bronchi and bronchioles

benign growth on mucous lining of nasal cavity

proliferation of fibrous tissues and damage of the alveolar walls

reduction in the secretion of surfactants by pneumocytes.

Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?

Inflammation of bronchioles; Decreased respiratory surface

Increased respiratory surface; Inflammation of bronchioles

Increased number of bronchioles; Increased respiratory surface

Decreased respiratory surface; Inflammation of bronchioles

Emphysema

எம்ஃபிசீமா

NCERT Class 11 · Breathing and Exchange of Gases · 5 NEET questions

Cigarette smoke is not just a toxin; it is a structural destroyer of your lungs. Emphysema is not reversible. Once the alveolar walls are gone, they are gone forever.

The idea

Emphysema is a chronic disorder primarily caused by cigarette smoking. It involves the damage of alveolar walls, leading to a significant decrease in the respiratory surface area. This structural loss impairs gas exchange efficiency within the lungs.

Why it matters

It is a pathological condition resulting from long-term exposure to irritants like smoke, leading to permanent lung damage.

NEET lens

NEET focuses on the cause-effect relationship: smoking leads to alveolar wall damage, which reduces respiratory surface area. Do not confuse this with Asthma or Occupational Respiratory Disorders. Remember: Emphysema is a chronic, irreversible structural change.

Clinical significance

The destruction of alveolar walls leads to air trapping and hyperinflation of the lungs. This drastically reduces the vital capacity and gas exchange surface, forcing the heart to work harder to compensate for chronic hypoxemia.

Introduction

Emphysema is a chronic obstructive pulmonary disease (COPD) characterized by destruction of alveolar walls → enlarged air spaces → reduced surface area for gas exchange → air trapping → breathlessness.

Core concept

Cause: primarily cigarette smoking (activates proteases, particularly elastase, in lungs). Mechanism: smoke → inflammation → neutrophils/macrophages release elastase → destroys elastin in alveolar walls → alveoli merge → larger, fewer, floppier air spaces. Consequences: Reduced surface area (from 70 m² to much less) → impaired O₂ diffusion. Loss of elastic recoil → airways collapse on expiration → air trapping → barrel chest. Increased RV and FRC. Reduced FEV₁/FVC ratio (obstructive pattern).

Go deeper

Alpha-1 antitrypsin deficiency: genetic cause of emphysema (young non-smokers). Alpha-1 antitrypsin (A1AT) normally inhibits neutrophil elastase. Without A1AT → elastase acts unchecked → alveolar destruction even without smoking. Treated with A1AT replacement therapy.

From Class 10

Long-term smoking can damage the lungs. Emphysema is a serious lung disease where alveolar walls break down, making breathing increasingly difficult.