Quick Reference Index

SAQ Topics Covered:

1. OxyHb Dissociation Curve - sigmoid shape, key points, right/left shift factors, role of 2,3-BPG
2. Hering-Breuer Reflex - stretch receptors → CN X → inhibits inspiration; protective mechanism
3. Bohr Effect - CO2/H+ shift OxyHb curve right; O2 unloading in active tissues
4. Haldane Effect - O2 binding causes CO2 release; accounts for ~50% of CO2 transport in lungs
5. P50 - PO2 at 50% Hb saturation; normal = 26 mmHg; indicator of O2 affinity
6. Pulmonary Circulation - low pressure/resistance, West's 3 zones, HPV (opposite to systemic)
7. High Altitude Acclimatisation - hyperventilation, polycythaemia, 2,3-BPG, EPO, AMS/HACE/HAPE
8. Peripheral Chemoreceptors - carotid bodies (CN IX), aortic bodies (CN X); respond mainly to low PO2
9. Alveolar Air Composition - VA, dead space, V/Q, RQ, alveolar gas equation
10. Hypoxia - 4 types (hypoxic, anaemic, stagnant, histotoxic); hypoxic hypoxia detailed
11. Surfactant - Type II pneumocytes, DPPC, Laplace's law, RDS/HMD in premature babies
12. Work of Breathing - 3 components: elastic (65%), tissue resistance (7%), airway resistance (28%)
13. Muscles of Respiration - diaphragm (primary), external intercostals, SCM, scalenes, abdominals
14. FRC - ERV + RV = ~2500 mL; O2 buffer, prevents collapse, reduced by anaesthesia/obesity
15. AMS - rapid ascent, hypoxic vasodilation, cerebral oedema; tx: descent, O2, acetazolamide, dexamethasone
16. Periodic Breathing & Ondine's Curse - Cheyne-Stokes (heart failure), CCHS (PHOX2B mutation)
17. Obstructive Lung Disease - FEV1/FVC <0.7, air trapping, COPD types, pink puffer vs blue bloater
18. Lung Volumes & Capacities - 4 volumes + 4 capacities; RV/FRC/TLC need plethysmography
19. V/Q Ratio - normal 0.8; dead space (PE) vs shunt (pneumonia); HPV improves matching
20. Kussmaul Breathing - deep regular rapid breathing; metabolic acidosis (DKA, uraemia); compensatory CO2 blow-off
21. Asphyxia, Cyanosis, Dyspnoea - definitions, types, mechanisms, clinical features

LAQ Topics Covered:

1. Neural Regulation - DRG, VRG, pre-Bötzinger complex, pneumotaxic/apneustic centres, reflexes
2. Chemical Control - central (CO2/H+, BBB, retrotrapezoid nucleus) + peripheral chemoreceptors; interaction
3. Lung Compliance - ΔV/ΔP, surface tension (2/3) + elastic recoil (1/3), HMD pathophysiology
4. Respiratory Membrane - 8 layers, Fick's law, factors affecting, DLCO/CO method principle
5. Pulmonary Ventilation - Boyle's law, pressure changes, negative pressure inspiration, PPB types and effects
6. Transport of O2 - dissolved (1.5%) + Hb-bound (98.5%), Hüfner's constant, cooperative binding, Fick's principle
7. CO2 Transport - dissolved (7%), bicarbonate (70%), carbamino (23%), chloride shift, Haldane effect

What's inside (23 pages):

Flowcharts included:

• SAQ 1 - OxyHb curve: sigmoid shape, right/left shift factors, 2,3-BPG role
• SAQ 2 - Hering-Breuer: step-by-step reflex pathway
• SAQ 3&4 - Bohr effect (left column) vs Haldane effect (right column), side-by-side
• SAQ 5 - P50: high vs low affinity comparison
• SAQ 6 - Pulmonary circulation: 6 feature boxes + HPV mechanism
• SAQ 7 - High altitude: 3-phase acclimatisation + HACE/HAPE branches
• SAQ 8 - Peripheral chemoreceptors: carotid vs aortic, stimuli ranked
• SAQ 10 - Hypoxia: all 4 types + hypoxic hypoxia causes expanded
• SAQ 11 - Surfactant: source → functions → RDS pathophysiology + treatment
• SAQ 12 - Work of breathing: 3 components + applied importance
• SAQ 14 - FRC: significance + factors reducing it
• SAQ 18 - Lung volumes: visual bar chart + capacities
• SAQ 19 - V/Q ratio: apex vs base, dead space vs shunt, HPV mechanism
• SAQ 15,16,17,20,21 - AMS, Periodic breathing, Obstructive disease, Kussmaul, Asphyxia/Cyanosis/Dyspnoea (grouped)
• LAQ 1 - Neural regulation: full brainstem pathway + reflex inputs
• LAQ 2 - Chemical control: central vs peripheral, side-by-side
• LAQ 3 - Lung compliance + HMD: Laplace law, factors, treatment
• LAQ 4 - Respiratory membrane: 8 layers + Fick's law + CO method
• LAQ 5 - Pulmonary ventilation: pressure changes + PPB types
• LAQ 6 - O2 transport: dissolved vs Hb-bound + Fick's principle
• LAQ 7 - CO2 transport: 3 forms + chloride shift + Haldane in lungs