Quick Reference Summary

Paper Structure Covered:

• Section A (38 marks): Q1 + Q2 + Q3
• Section B (37 marks): Q4 + Q5 + Q6

Key Points to Remember for the Exam:

• Diagnosis = Acute MI (history + risk factors)
• Phase 0 (QRS) = fast Na⁺; Phase 2 (ST segment) = Ca²⁺ plateau; Phase 3 (T wave) = K⁺ efflux
• Inferior MI = ST elevation in II, III, aVF (RCA territory)

• RAAS = Renin → Ang I → ACE → Ang II → vasoconstriction + aldosterone
• Coagulation: Extrinsic (TF + VII) vs Intrinsic (XII→XI→IX→VIII) → common pathway (X→V→prothrombin→thrombin→fibrin)
• Counter-current multiplier = TAL actively pumps NaCl, creates 300-1200 mOsm corticopapillary gradient
• Distributive shock: Septic, Anaphylactic, Neurogenic (all cause ↓ SVR despite ↑/normal CO)

• Neutrophils: Chemotaxis → Phagocytosis → Respiratory burst (NADPH oxidase → O₂⁻ → HOCl via MPO)
• Erythroblastosis: Rh- mother sensitized in 1st pregnancy → anti-D IgG crosses placenta in 2nd pregnancy → fetal hemolysis
• Cushing's Reflex: ↑ ICP → brain ischemia → ↑ BP + bradycardia + irregular breathing (triad = ominous sign)
• Wenckebach = Mobitz I = progressive PR prolongation → dropped beat → reset

• DRG = inspiration rhythm; Pneumotaxic center = limits inspiration; Apneustic center = prolongs inspiration
• Cheyne-Stokes = cyclic apnea-hyperpnea, seen in heart failure (long circulation time)
• Kussmaul = deep, rapid, regular breathing = compensation for metabolic acidosis (DKA)

• HCl: H⁺/K⁺-ATPase (proton pump) on parietal cells; stimulated by ACh, histamine, gastrin
• Deglutition: Oral (voluntary) → Pharyngeal (reflex, glottis closes) → Esophageal (peristalsis, LES relaxes)
• TGF: Macula densa senses NaCl → adenosine → afferent arteriole constriction → ↓ GFR (negative feedback)
• DCT/CD: Na⁺ via ENaC (aldosterone), Water via AQP2 (ADH), H⁺ via intercalated cells

• Caisson disease = rapid ascent → N₂ bubbles → joint pain, neurological deficits; treat with hyperbaric O₂
• MMC: 90-120 min cycles (fasting); Phase III = "housekeeper wave"; regulated by Motilin
• Moderate exercise: ↑ HR, ↑ SBP, DBP unchanged, ↑ CO, ↓ TPR (muscle vasodilation)
• Heat stroke: Core temp >40°C + CNS dysfunction; classic = anhidrotic; treat with rapid cooling