Heart Anatomy - Lecture Notes

Jul 26, 2024

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