Complete Mnemonic Collection
1. The Four Basic Lung Volumes — "Tiny Insects Eat Rice" T = TV (Tidal Volume) I = IRV (Inspiratory Reserve Volume) E = ERV (Expiratory Reserve Volume) R = RV (Residual Volume)
2. Lung Capacities in Order — "In Every Final Voyage Travel" I = IC (Inspiratory Capacity) E = EC (Expiratory Capacity) F = FRC (Functional Residual Capacity) V = VC (Vital Capacity) T = TLC (Total Lung Capacity)
3. VC Formula Memory "VC = Everything EXCEPT RV" VC = TV + IRV + ERV (all the ones you CAN voluntarily move) TLC = VC + RV (add the one you CAN'T — the Residual)
4. CO2 Transport — "BCD = 70-23-7" B = Bicarbonate (HCO3–) = 70% C = Carbaminohaemoglobin = 23% D = Dissolved in plasma = 7% Memory trick: "B is the Biggest, C comes next, D is the Dregs"
5. Bohr Effect (Right Shift Factors) — "CADET, face Right!" C = CO2 (increased) A = Acid / H+ (decreased pH) D = DPG/2,3-BPG (increased) E = Exercise T = Temperature (elevated) → All these → RIGHT shift → MORE O2 released to tissues
6. Inspiration Muscles — "DEx" D = Diaphragm contracts (flattens) Ex = External intercostals (lift ribs up and out) DEx → inspiration starts
7. Forced Expiration Muscles — "IA Push" I = Internal intercostals (pull ribs down and in) A = Abdominal muscles (push diaphragm up) → Both together = forced air out
8. Three Layers of Diffusion Membrane — "EBE" E = (Alveolar) Epithelium B = Basement membrane E = (Capillary) Endothelium EBE = 3 layers (Epithelium–Basement–Endothelium)
9. Right Lung vs Left — "Three's Company on the Right" Right = 3 lobes (Three's Company) Left = 2 lobes (Left is Less → because of cardiac notch)
10. Medulla vs Pons Control — "Medulla Makes rhythm, Pons Pauses it" Medulla = Makes (initiates) the breathing rhythm Pons (pneumotaxic) = Pauses (limits) inspiration
11. Partial Pressure Values at Alveoli O2: Alveoli 104 → Blood 40 (O2 goes DOWN into blood) CO2: Blood 45 → Alveoli 40 (CO2 goes OUT into alveoli) Remember: "104-40 for O2; 45-40 for CO2"