🧠 Step 8 — Student Memory Support
This final section is designed for rapid revision, memory strengthening, and last-day exam preparation. Use it after completing the topic to recall high-yield facts quickly.
🎯 How to Use This Section
- Revise flashcards for quick recall.
- Use mnemonics to remember lists.
- Review memory tables for comparison-based questions.
- Read clinical hooks before exams.
- Mark the topic complete after revision.
🃏 1️⃣ High-Yield Flashcards
Which ion causes rapid depolarization in ventricular muscle?
Sodium
Which ion is mainly responsible for plateau phase?
Calcium
Which channels produce the plateau phase?
L-type calcium channels
Which ion mainly causes repolarization?
Potassium
Which structure electrically connects cardiac muscle cells?
Gap junctions
What prevents tetanic contraction in cardiac muscle?
Long refractory period
Calcium binds to which protein during contraction?
Troponin C
Define positive chronotropic effect.
Increased heart rate
Define positive inotropic effect.
Increased force of contraction
Define positive dromotropic effect.
Increased conduction velocity
Which phase of ventricular action potential represents plateau?
Phase 2
Which pump removes calcium into sarcoplasmic reticulum during relaxation?
SERCA pump
🧠 2️⃣ Mnemonics
Mnemonic Title:
Phases of Ventricular Action Potential
Mnemonic Word:
“Really Important Plateaus Relax Fast”
Meaning:
- Rapid depolarization → Phase 0
- Initial repolarization → Phase 1
- Plateau → Phase 2
- Repolarization → Phase 3
- Resting phase → Phase 4
Mnemonic Title:
Cardiac Functional Effects
Mnemonic Word:
“CID”
Meaning:
- Chronotropic → Heart rate
- Inotropic → Force
- Dromotropic → Conduction
Mnemonic Title:
Main Ions in Cardiac Action Potential
Mnemonic Word:
“Na–Ca–K”
Meaning:
- Sodium → Depolarization
- Calcium → Plateau
- Potassium → Repolarization
📋 3️⃣ Memory Tables
Table 1 — Cardiac vs Skeletal Muscle
| Feature | Cardiac Muscle | Skeletal Muscle |
|---|---|---|
| Action potential duration | Long | Short |
| Plateau phase | Present | Absent |
| Tetany | Cannot occur | Can occur |
| Extracellular calcium dependence | High | Lower |
| Refractory period | Long | Short |
Table 2 — Functional Effects
| Effect | Main Change |
|---|---|
| Chronotropic | Heart rate |
| Inotropic | Force of contraction |
| Dromotropic | Conduction velocity |
⚡ 4️⃣ Rapid Revision Points
Must Remember:
- Phase 0 = Sodium influx
- Phase 2 = Calcium plateau
- Phase 3 = Potassium efflux
- Plateau prolongs contraction
- Long refractory period prevents tetany
- Cardiac muscle requires extracellular calcium
- Gap junctions form functional syncytium
- Calcium binds troponin C
- SERCA pump causes relaxation
- Hyperkalemia causes arrhythmias
- Calcium channel blockers slow AV conduction
- SA node depolarization depends mainly on calcium
🩺 5️⃣ Clinical Memory Hooks
Clinical Hook:
Hyperkalemia → Reduced membrane excitability → Arrhythmias
Clinical Hook:
Calcium channel blockers → Reduced AV conduction → Slower heart rate
Clinical Hook:
Long QT syndrome → Delayed repolarization → Ventricular arrhythmias
Clinical Hook:
Myocardial ischemia → Abnormal ion handling → Ventricular fibrillation
Clinical Hook:
Heart failure → Reduced calcium handling → Weak contraction