Lesson Objectives:

• Review key anatomical structures and their functions.

• Understand the principles of myocardial perfusion and coronary circulation.

• Discuss the role of the autonomic nervous system in cardiovascular function.

Key Concepts

🔹 Coronary Circulation:
The heart receives its blood supply from the left and right coronary arteries:

• Left main coronary artery (LMCA) → bifurcates into the LAD (left anterior descending) and LCx (left circumflex).

• Right coronary artery (RCA) → supplies the right atrium, right ventricle, SA node, and AV node.

🔹 Myocardial Perfusion:

• Coronary blood flow occurs mainly during diastole (unlike systemic circulation, which is continuous).

• Factors affecting perfusion include coronary artery stenosis, tachycardia, and endothelial dysfunction.

🔹 Electrophysiology & Conduction System:
The heart’s electrical conduction system includes:
1️⃣ Sinoatrial (SA) Node – the natural pacemaker (60-100 bpm).
2️⃣ Atrioventricular (AV) Node – delays conduction, allowing ventricular filling.
3️⃣ Bundle of His & Purkinje Fibers – ensure synchronized ventricular contraction.