Heart Anatomy and Function

Overview of the Heart

  • Location and Orientation
    • The heart is located in the thoracic cavity, positioned between the lungs and above the diaphragm, with significant structures like the trachea, major blood vessels, and ribs surrounding it.

Superficial Anatomy

  • Anterior Surface Features:
    • Key structures include the ascending aorta, superior vena cava, and auricles of both atria.
  • Posterior Surface Features:
    • Shows major landmarks including coronary arteries and veins, and pulmonary veins.

Coronary Circulation

  • Important vessels include:
    • Anterior Surface: Anterior interventricular artery, great cardiac vein, etc.
    • Posterior Surface: Circumflex artery, marginal artery, coronary sinus, etc.

Internal Anatomy

  • Valves:
    • Key valves include tricuspid, bicuspid (mitral), pulmonary, and aortic valves.
  • Components:
    • Chordae tendineae, papillary muscles, and muscle types in heart walls (
    • Left ventricle has a thicker wall than the right, indicative of stronger pumping ability).

Cardiac Electrical System

  • Components:
    • Sinoatrial node (SA node), Atrioventricular node (AV node), Bundle of His, Purkinje fibers.
  • ECG Waves:
    • P Wave: Atrial contraction.
    • QRS Complex: Ventricle contraction.
    • T Wave: Represents ventricular repolarization.