Lecture Notes: Structure and Function of the Heart

Introduction

• The heart is slightly tilted to the right in the chest.
• Two main colors for diagrams:
  • Blue: Deoxygenated blood (right side of the heart).
  • Red: Oxygenated blood (left side of the heart).

Structure of the Heart

• Chambers of the Heart:

  • Right Atrium (RA)
  • Left Atrium (LA)
  • Right Ventricle (RV)
  • Left Ventricle (LV)

• Apex of the Heart: Bottom area, peak or point of the heart.

• Base of the Heart: Superior region, the right side and a bit of the left.

• Location in the Body: The heart sits in the mediastinum of the thoracic cavity.

Blood Flow Basics

• Arteries: Carry blood away from the heart ("a" for "away").
• Veins: Bring blood back to the heart.

Heart Lining and Structure

• Muscle of the Heart (Myocardium): Thick layer (myo = muscle).
• Endocardium: Inner layer of the heart (endo = inner).
• Visceral Pericardium (Epicardium): Outer layer on top of the heart.
• Parietal Pericardium (Serous Pericardium): Middle layer forming the pericardial sac.
• Fibrous Pericardium: Tough outer layer for protection.
• Pericardial Space: Contains pericardial fluid to reduce friction.

Blood Flow Through the Heart

• Deoxygenated Blood:

  • Enters RA from the body via the superior and inferior vena cava.
  • From RA to RV through the tricuspid valve.
  • RV to lungs via pulmonary valve and pulmonary arteries.

• Oxygenated Blood:

  • Returns from lungs to LA via pulmonary veins.
  • LA to LV through the bicuspid (mitral) valve.
  • LV to body via aortic valve and aorta.

Key Valves

• Tricuspid Valve: Between RA and RV.
• Pulmonary Valve: From RV to pulmonary trunk.
• Bicuspid (Mitral) Valve: Between LA and LV.
• Aortic Valve: From LV to aorta.

Blood Vessels and Aorta

• Coronary Arteries: Supply blood to the heart itself.

  • Left Coronary Artery
  • Right Coronary Artery
  • Left Anterior Descending Artery

• Parts of the Aorta:

  • Ascending Aorta
  • Aortic Arch
  • Descending Aorta
  • Thoracic Aorta (above diaphragm)
  • Abdominal Aorta (below diaphragm)

• Branches off Aortic Arch:

  • Brachiocephalic Trunk
  • Right and Left Common Carotid Arteries
  • Right and Left Subclavian Arteries
  • Right and Left Vertebral Arteries

Internal Structures

• Interatrial Septum: Separates RA and LA.
• Interventricular Septum: Separates RV and LV.
• Auricles and Pectinate Muscles: Muscles on atrial walls.
• Trabeculae Carneae: Internal ridges in the ventricles.
• Papillary Muscles and Chorda Tendineae: Contract to close valves, essential for valve function.

Summary

• We covered the basic structure of the heart, its linings, and how blood flows through the heart.
• Discussed major blood vessels and internal structures, concluding the detailed overview of the heart's anatomy and function.