1. The Cardiovascular System (I) The Heart

2. Mediastinum

3. Mediastinum The space between the 2 lungs Sup.: FIRST RIB Inf.: diaphragm Ant.: sternum Post.: VERTEBRAL COLUMN

4. Heart Surfaces 1. Anterior (sternocostal): 2. Inferior (diaphragmatic): 3. Base: mostly Lf. Atrium Posterior surface of the heart 4. Apex: tip of Lt ventricle

5. Inferior Surface Posterior Surface Anterior Surface

6. Site for posterior surface of the heart (Base) Site for inferior surface of the heart (Diaphragmatic)

7. Heart Borders Right border: From inferior surface to base Left Border Pulmonary border From apex to base

8. Surface projection Determined by 4 points -Superior right point 3 rd Rt CC -Superior left point 2 nd Lt CC -Inferior left point 5 th intercostal space -Inferior right point 6 th Rt CC

9. Covering of the Heart

10. Coverings of the Heart Covering fibroserous sac of 2 layers of tissues that encloses the heart Outer: fibrous (fibrous pericardium) Inner: serous (serous pericardium) Fxn.: 1. Protection 2. Lubrication (  friction)

11. Fibrous Pericardium Strong single layer of dense CT fuse to great vessels Prevent overstretching Protection and anchorage

13. Serous Pericardium 2 layers of mesothelial cells that are continuous with each other Outer (Parietal): lines fibrous pericardium reflects around the roots of large vessels to become continuous with Inner (Visceral): closely attached to the heart  Epicardium (outer heart layer)

15. Layers of the Heart wall 3 layers: 1.Epicardium: visceral layer of serous pericardium 2.Myocardium: cardiac muscle 3.Endocardium: thin layer of endothelial cells supported by thin layer of CT Myocarditis: inflammation of myocardium Endocarditis: inflammation of endocardium

17. Fibrous Skeleton of the Heart 4 rings of dense CT Surround the valves Fuse with one another

18. Chambers of the heart 4 chambers: -2 atria -2 ventricles Rt ½ of Heart: Pulmonary pump Lt ½ of Heart: Systemic pump

20. Right Atrium - Receives deO 2 bld. From the body - Forms Rt. Border of the heart - Composed of: smooth walled chamber & rough out pouch (auricle) Rough = pectinate muscle - Border between: crista terminalis Outside: sulcus terminalis - Atrial septum ( fetal remnants ): Fossa ovalis Anulus ovalis

21. Openings of Rt. Atrium 1. SVC: bld. from upper body 2. IVC: bld. From lower body / larger 4. Coronary Sinus: Between IVC & A-V orifice Bld form heart wall 3. A-V orifice: Ant. to IVC Guarded by tricuspid valve

22. Rt. Ventricle muscular projections: 1. Papillary muscles: -Cone-shaped projections -Attach the cusps of A-V valve via Chordae tendineae 2. Trabeculae carneae: -prominent muscular ridges

23. Openings A-V orifice: guarded by tricuspid valve Pulmonary opening: opens into pulmonary trunk guarded by pulmonary valve

24. Lf. Atrium Most of the base of Heart Inner wall: Smooth anteriorly and posteriorly Pectinate muscles are confined to Lt auricle 4 openings for P. V.: blood from lungs 1 opening for mitral valve

25. Left Ventricle Thickest part of the Heart Forms apex of Heart papillary m. Chordae tendineae Opens into Ascending Aorta ** Ductus arteriosus

26. Heart Valves 4 valves: - 2 semilunar: Aortic & Pulmonary - 2 A-V: Tricuspid & Mitral

27. Semilunar Valves Pulmonary: 3 Crescent moon-shaped cusps Cusp: folding of endocardium with C.T. inside Sinus: space behind each cusp Aortic : similar to pulmonary 2 post. & 1 ant. Cusps Ensures one way blood flow from ventricles into arteries

28. Atrioventricular Valves 1. Tricuspid -Rt. A-V orifice -3 cusps: 2. Mitral Valve: -Left A-V orifice -2 cusps (bicuspid) Cusps are Attached to papillary m. through Chordae tendineae Valves ensure one way flow of blood from atria to ventricles

29. Conducting System Sino-Atrial node (SA node) Atrio-Ventricular node (AV node) Atrio-Ventricular Bundle & branches (bundle of His) Purkinje fibers (subendocardial plexus)

30. Arterial Supply of the Heart Coronary arteries: Right Coronary artery Left Coronary artery From ascending aorta

31. Right Coronary Artery Between pulmonary trunk & Rt. Auricle  Rt. AV groove  (Posteriorly) anastomose with Lf. Coronary Branches: 1. Rt. Marginal artery 2. Post. interventricular

32. Left Coronary Artery Larger but shorter Arises between pulmonary trunk & Lt Auricle Divides to: 1. ant. interventricular a. 2. circumflex a

34. Venous Drainage 3 main veins  Coronary Sinus 1. Great: Ant 2. Middle: Post 3. Small: Rt. Margin -Anterior cardiac veins Open directly into Rt atrium

35. Blood circulation Pulmonary Circulation: Rt ventricle Lungs Lt atrium Systemic Circulation: Lt ventricle Entire Body Rt atrium