Heart Anatomy Lecture Notes

Surfaces of the Heart

• Anterior surface: Front side of the heart.
• Posterior surface: Back side of the heart.
• Inferior surface: Bottom side of the heart.
• Apex: Tip of the heart, points left and downward.
• Superior surface (Base): Top side of the heart, points toward right shoulder.

Anterior Surface Structures

• Auricles: Fatty pouches on both sides
  • Left auricle
  • Right auricle
• Pulmonary Trunk: Carries deoxygenated blood from right ventricle to lungs.
  • Branches to Left Pulmonary Artery
  • Right Pulmonary Artery (seen later)
• Aorta: Major artery carrying oxygenated blood from heart to body.
  • Ascending Aorta
  • Aortic Arch
    • Brachiocephalic Artery
      • Right Subclavian Artery
      • Right Common Carotid Artery
    • Left Common Carotid Artery
    • Left Subclavian Artery
  • Descending Aorta (seen later)

Right Side of the Heart

• Right Atrium
• Superior Vena Cava: Dumps deoxygenated blood into right atrium.
  • Right Brachiocephalic Vein
  • Left Brachiocephalic Vein
  • Azygos Vein: Feeds into Superior Vena Cava
  • Inferior Vena Cava: Shown later

Posterior Surface Structures

• Descending Aorta (Thoracic Aorta)
• Pulmonary Arteries: Deoxygenated blood to lungs
  • Right Pulmonary Artery
  • Left Pulmonary Artery
• Pulmonary Veins: Oxygenated blood from lungs
  • Right Pulmonary Veins
  • Left Pulmonary Veins
• Azygos Vein: Brings blood from common iliacs, bypasses inferior vena cava

Coronary Circulation

• Coronary Arteries: Supply blood to heart muscle
  • Right Coronary Artery
  • Left Coronary Artery
• Anterior Interventricular Artery (Left Anterior Descending Artery): Common site for myocardial infarctions.
• Circumflex Artery: Supplies lateral walls of the left ventricle.
• Veins in Coronary Circulation
  • Great Cardiac Vein: Follows the anterior interventricular artery
  • Posterior Vein of the Left Ventricle: Drains into coronary sinus
  • Small Cardiac Vein: Follows marginal artery
  • Coronary Sinus: Collects blood from cardiac veins, empties into right atrium

Heart Valves and Chambers

• Right Atrium
  • Tricuspid Valve: Between right atrium and right ventricle
  • Chordae Tendineae: Tendon-like cords attached to papillary muscles
  • Papillary Muscles: Anchor chordae tendineae
  • Fossa Ovalis: Scar tissue from foramen ovale
  • Coronary Sinus Opening: Empties into right atrium
• Right Ventricle
  • Pulmonary Semilunar Valve: Between right ventricle and pulmonary trunk
  • Ligamentum Arteriosum: Remnant of fetal ductus arteriosus

Pulmonary and Systemic Circulation

• Left Atrium
  • Right Pulmonary Veins
  • Left Pulmonary Veins
  • Mitral Valve (Bicuspid Valve): Between left atrium and left ventricle
• Left Ventricle
  • Aortic Semilunar Valve: Prevent back-flow into left ventricle
  • Interventricular Septum: Wall between ventricles; defects can occur here

Heart Muscle and Tissue Layers

• Myocardium: Muscular layer of the heart
• Endocardium: Lining of inner chambers and valves
• Epicardium: Outer layer of the heart, made of mesothelium

Special Muscle Structures

• Pectinate Muscles: In anterior walls of atria
• Trabeculae Carneae: In walls of ventricles

Arterial Anastomoses

• Provide alternative routes for blood flow in case of blockages
• Examples:
  • Anterior Interventricular Artery and Circumflex Artery
  • Posterior Interventricular Artery and Circumflex Artery
  • Posterior Interventricular Artery and Marginal Artery
  • Marginal Artery and Anterior Interventricular Artery