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🌬️ Chapter 15: Breathing and Exchange of Gases – Part 4

❌ Respiratory Disorders & Final Recap

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🚨 Common Respiratory Disorders

1️⃣ Asthma

• Chronic inflammation of bronchi and bronchioles.

• Causes:

  • Allergens (dust, pollen)

  • Cold air, pollution, exercise

• Symptoms:

  • Wheezing

  • Shortness of breath

  • Chest tightness

  • Coughing

• Treated with bronchodilators and anti-inflammatory drugs.

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2️⃣ Emphysema

• Alveolar walls are damaged, reducing surface area for gas exchange.

• Main cause: Smoking.

• Results in:

  • Poor O₂ exchange

  • Breathlessness

  • Reduced lung elasticity

🧠 Alveolar walls fuse → less surface → poor oxygenation

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3️⃣ Bronchitis

• Inflammation of bronchial tubes.

• Can be acute or chronic.

• Leads to:

  • Cough

  • Excess mucus

  • Breathing difficulty

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4️⃣ Occupational Lung Diseases

Due to long-term exposure to industrial dust and chemicals:

Disease	Cause	Affected People
Silicosis	Silica dust	Miners, quarry workers
Asbestosis	Asbestos particles	Construction workers
Black Lung	Coal dust	Coal miners

Proper protective gear and ventilation systems are preventive.

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5️⃣ Hypoxia

• Oxygen deficiency in body tissues.

• Causes:

  • High altitude

  • Anemia

  • Respiratory disorders

• Symptoms:

  • Cyanosis (bluish skin)

  • Drowsiness

  • Rapid heartbeat

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6️⃣ Pneumonia

• Infection of alveoli (usually by bacteria/virus).

• Alveoli fill with fluid or pus, obstructing gas exchange.

• Symptoms:

  • Fever

  • Chest pain

  • Cough with phlegm

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🧠 NEET PYQs – Respiratory Disorders

1. Emphysema is characterized by:

   • A) Inflammation of alveoli

   • B) Collapse of trachea

   • C) Destruction of alveolar walls

   • D) Excess mucus in lungs
     ✅ Answer: C) Destruction of alveolar walls

2. Which disease is caused by prolonged exposure to asbestos?

   • A) Tuberculosis

   • B) Silicosis

   • C) Asbestosis

   • D) Black lung
     ✅ Answer: C) Asbestosis

3. Asthma is caused by:

   • A) Infection in lungs

   • B) Genetic mutation

   • C) Allergy-induced narrowing of bronchioles

   • D) Blood clot in lung
     ✅ Answer: C) Allergy-induced narrowing of bronchioles

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📌 Final Revision Summary

Concept	Quick Facts
Pulmonary Volume	Tidal, IRV, ERV, RV – total = 6000 mL (approx.)
Exchange of Gases	pO₂ and pCO₂ gradients drive O₂ in, CO₂ out
Oxygen Transport	Mostly by Hb → Oxyhaemoglobin
CO₂ Transport	70% as HCO₃⁻, 20-23% HbCO₂, 7% dissolved
Regulation	Brainstem centers (Medulla, Pons), CO₂-sensitive
Disorders	Asthma, Emphysema, Bronchitis, Pneumonia, Hypoxia, etc.

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🧠 Pro Tips for NEET:

• Master graph-based questions like the oxygen dissociation curve.

• Don't ignore small data like pO₂/pCO₂ values.

• Pay attention to diseases, causes, and their physiological effects.

• Practice assertion-reason type questions for conceptual grip.

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📘 Keep exploring more NEET-focused content:

• 🌿 biologyatease1.blogspot.com

• 🧪 neetpyqall.blogspot.com

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