Lecture on the Heart Anatomy

Overview

• Examination of the heart's external and internal features.
• Focus on the anterior or sternal costal surface, and detailed exploration of heart chambers.

External Features

Anterior or Sternal Costal Surface

• Apex: Points inferiorly to the left, composed of the left ventricle.
• Interventricular Septum: Wall between the two ventricles, indicated by the interventricular groove.
• Ventricular Placement:
  • Left Ventricle: Identified by the location of the interventricular septum and groove.
  • Right Ventricle: Forms most of the anterior surface.
  • Right Atrium: Identified by the coronary sulcus and the right atrium's oracle.

Internal Features

Right Atrium

• Pectinate Muscles: Comb-like ridges on the anterior wall, radiating from the crista terminalis.
• Sinus Venarum: Smooth posterior wall where superior and inferior vena cava empty.
• Fossa Ovalis: Oval depression, a remnant of the foramen ovale.
• Right Atrioventricular Valve: Typically tricuspid, sometimes only two valves.

Right Ventricle

• Trabeculae Carneae: Muscular ridges on the interior wall.
• Papillary Muscles: Three sets - anterior, posterior, septal.
• Chordae Tendineae: Fibrous cords connecting papillary muscles to valve cusps.
• Moderator Band: Contains part of the heart's conducting system.
• Conus Arteriosus / Infundibulum: Smooth exit area for blood.
• Pulmonary Valve: Semilunar valve, prevents backflow.

Blood Flow from Right Ventricle

• Blood exits through the pulmonary trunk to right and left pulmonary arteries.
• Blood returns oxygenated to the left atrium via pulmonary veins.

Left Atrium

• Smooth walled.
• Left Atrial Oracle: Contains pectinate muscles.
• Bicuspid Valve (Mitral Valve): Opening into the left ventricle.

Left Ventricle

• Trabeculae Carneae: More developed than in the right ventricle.
• Papillary Muscles: Two sets due to the bicuspid valve.
• Thick Wall: Due to higher pressure requirements.
• Aortic Valve: Semilunar valve similar to the pulmonary valve.

Aorta and Coronary Arteries

• Blood exits the left ventricle through the aortic valve into the ascending aorta.
• Coronary Arteries: First branches of the aorta providing blood to the heart.

Summary

• Detailed exploration of the heart’s structure and function.
• Discussed both external features and internal chamber characteristics.