Heart

Heart

1. Where to auscultate to hear valves?

   • Pulmonary: Left side, 2nd intercostal space by sternum. Aortic: Right side, 2nd intercostal space, by sternum. Tricuspid: 4th intercostal space on left side of sternum. Mitral: 5th intercostal space, midclavicular line, left side.

2. Pericardium

   • Fibrous - strong outter layer Serous - Divided into two. Parietal: outter layer. Visceral: covering the heart. Pericardial cavity filled with pericardial fluid between them.

3. Reflections of serous pericardium?

   • Transverse
     • between aorta and pulmonary arteries. superior vena cava behind.
   • Oblique
     • between pulmonary veins and inferior vena cava. in front of oesophagus.

4. 3 layers of the heart?

   • Endocardium
     • Smooth lining of heart chambers and heart valves.
   • Myocardium
     • Cardiac muscle tissue
   • Epicardium
     • Same as visceral pericardium. It is the outer layer of the heart wall.

5. Heart pain referred to where?

   • Heart pain is referred to either left jaw or left arm. Nerve fibers follow sympathetics back to spinal cord where cell bodies are located in thoracic dorsal root ganglia 1-4. Any dermatomes with their cell bodies here too could get the pain.

6. Shunts in venous circulation?

   • Ductus Arteriosus
     • Connect pulmonary artery to aortic arch. Changes to ligamentum arteriosum.
   • Ductus venosus
     • Shunts 50% of blood of umbilical vein directly to inferior vena cava. Allows oxygenated blood from placenta to bypass the liver.
   • Foramen ovale
     • Blood from right atrium to left atrium. Closes after birth when left atrial pressure becomes higher than right - forces septum primum against septum secundum - eventually fuse.

7. Coronary circulation

   • Right coronary artery
     • Marginal artery down anterior surface of heart. Posterior interventricular artery down posterior surface of heart. Nodal artery to SA node in most people which comes off straight away.
   • Left coronary artery
     • Anterior interventricular artery down anterior surface of heart. Circumflex branch wraps around heart.
   • Great cardiac vein
     • Runs down anterior interventricular groove. Gives off posterior vein to left ventricle. Joins Coronary sinus.
   • Middle Cardiac vein
     • Runs down posterioir interventricular groove.
   • Anterior cardiac veins
     • Down anterior right surface of heart.
   • Small cardiac veins
     • Down anterior right surface of heart.