1. Pericardium and External features of Heart Dr. Sama ul Haque Dr Rania Gabr

2. Objectives Define pericardium. Differentiate between fibrous and serous pericardium. Define pericardial sinuses. Identify the borders and surfaces of the heart. Describe the structure of the heart

3. Pericardium Pericardium is a fibroserous sac that encloses the heart and roots of the great vessels. Relations of Pericardium: Anterior:  Body of Sternum  2 nd to 6 th costal cartilages Posterior:  5 th to 8 th thoracic vertebrae

4. Layers of the Pericardium 1. Fibrous Pericardium Attached anteriorly to the sternum by Sternopericardial ligaments. 2. Serous Pericardium Two Layers: a. Parietal b. Visceral

5. Serous Pericardium

6. Pericardial Sinuses

7. The lines of reflection between visceral and parietal pericardium form two pericardial sinuses, the transverse pericardial sinus and the oblique pericardial sinus. The transverse pericardial sinus lies anterior to the superior vena cava and posterior to the ascending aorta and pulmonary trunk. The oblique pericardial sinus lies posterior to the heart in the pericardial sac. Pericardial Sinuses

8. 1.Fibrous Pericardium and Parietal layer of serous Pericardium: By Phrenic nerves 2. Visceral layer of Serous Pericardium: By Sympathetic trunk and vagus nerves Nerve supply of the Pericardium

9. Location of the Heart

10. Angle of Louis It is the angle at which the manubrium and sternum meet/articulate. It is an anatomical landmark for finding the second rib, approx. area of the carina

11. Location of Heart

12. It lies in the middle mediastinum. The Heart is somewhat pyramidal in shape, having: Apex Sterno-costal (anterior surface) Base (posterior surface). Diaphragmatic (inferior surface) It consists of 4 chambers, 2 atria (right& left) & 2 ventricles (right& left) Location of the Heart

13. Borders of the Heart Right border: formed by right atrium Left border: formed by left auricle and left ventricle Lower border: formed by right atrium & mainly by right ventricle + apical part of left ventricle Upper border: Is formed by the 2 atria

14. Surfaces of the Heart Sternocostal surface (Anterior surface): Mainly formed by right atrium and right ventricle. Diaphragmatic surface (Inferior surface): Mainly formed by right and left ventricles. Small portion is formed by right atrium. Base (Posterior surface): Mainly formed by left atrium. Apex: formed by left ventricle

15. Apex of the heart Directed downwards, forwards and to the left. It is formed by the left ventricle. lies at the level of left 5 th intercostal space 3.5 inch from midline. Note that the base of the heart is called the base because the heart is pyramid shaped; the base lies opposite the apex. The heart does not rest on its base; it rests on its diaphragmatic (inferior) surface

16. Sterno-costal (anterior)surface Divided by coronary (atrio- ventricular) groove into :  Atrial part, formed mainly by right atrium.  Ventricular part, the right 2/3 is formed by right ventricle, while the left l1/3 is formed by left ventricle.  The 2 ventricles are separated by anterior interventricular groove, which lodges :  Anterior interventricular artery (branch of left coronary).  Great cardiac vein.  The coronary groove lodges right coronary artery. This surface is formed mainly by the right atrium and the right ventricle.

17. Diaphragmatic (Inferior)surface  Formed by the 2-ventricles, mainly left ventricle (left 2/3).  Slightly concave as it rests on diaphragm.  Directed inferiorly & backward.  Separated from base of heart by posterior part of coronary sulcus.  The 2-ventricles are separated by posterior interventricular groove which lodges:  Posterior interventricular artery  Middle cardiac vein

18. Base of the Heart (posterior surface)  It is formed by the 2 atria, mainly left atrium, into which open the 4 pulmonary veins.  It is directed backwards.  Lies opposite middle thoracic vertebrae (5-7).  Is separated from the vertebral column by descending aorta, esophagus and oblique sinus of pericardium.  Bounded inferiorly by post. part of coronary sulcus, which lodges the coronary sinus. Left atrium

19. Heart (Anterior Surface) Anterior Surface Apex

20. Heart (Posterior and inferior surfaces) Base Inferior Surface

21. Heart (Anterior view) SVC AA PT RVLV IVC RA SVC: Superior vena cava AA: Ascending Aorta PT: Pulmonary Trunk RA: Right Auricle RV: Right ventricle LV: Left ventricle IVC: Inferior vena cava

22. Heart (Posterior view) LA RA LV IVC LA: Left auricle RA: Right auricle LV: Left ventricle IVC: Inferior vena cava

23. Heart (Posterior view)

24. Heart (Anterior interventricular Sulcus or Groove) AIS

25. PIS CS Heart (Posterior interventricular Sulcus or Groove) Coronary or Atrioventricular Sulcus or Groove

26. Coverings & Wall of the Heart