Breathing and Exchange of Gases
This section contains 30 high-frequency NEET/AIPMT PYQs, strictly aligned with NCERT. Questions from this chapter repeatedly test alveoli structure, lung volumes, gas transport, haemoglobin dissociation curve, and regulation of respiration.
Important NEET Exam Tips
- CO₂ is the main regulator of respiration, not oxygen
- Emphysema = destruction of alveolar walls (surface area ↓)
- O₂–Hb dissociation curve: Right shift → more O₂ unloading (Bohr effect)
- CO₂ transport: ~70% as bicarbonate, ~20–25% as carbamino-Hb
- Residual volume prevents lung collapse
- Alveoli are lined by simple squamous epithelium
- Trachea has C-shaped cartilaginous rings (open posteriorly)