2. Introduction Cardiovascular system: heart, blood, and blood vessels
Cardiac muscle
Makes up bulk of heart
Provides force to pump blood
Function: transports blood

3. The Anatomy of the Heart

4. Introduction Located in the mediastinum
Surrounded by pericardial sac, which has two following parts:
Fibrous pericardium: outer layer, which is made of tough fibrous connective tissue and connects to the large blood vessels that enter and exit the heart.
Serous pericardium: inner layer,thin and delicate.

5. Introduction

6. The Layers of the Heart Wall
Epicardium/visceral pericardium: outermost layer, thin, transparent layer.
Pericardial cavity: separates epicardium and serous pericardium. This cavity contains a watery fluid called pericardial fluid, which reduces friction and erosion of tissue between these membranes as the heart expands and contracts during a cardiac cycle.
If an inflammation of the inner most layer of pericardial sac develops, it is known as pericarditis.
Myocardium: middle muscular layer, layer of cardiac muscle tissue. It is involuntary, striated, and branched. This layer is arranged in interlacing bundles and is the layer responsible for contraction of the heart.

7. Endocardium: lines the third or innermost layer of the heart
Endocardium: lines the third or innermost layer of the heart .Thin layer of connective tissue penetrated by tiny blood vessels and bundles of smooth muscle.It covers the valves of the heart and the chordae tendineae of the valves.

8. The Layers of the Heart Wall

9. The Layers of the Heart Wall (cont’d.)

10. The Chambers of the Heart
Upper chambers: right and left atria .Each atrium has an external appendage called an auricle, names because of its similarity to the ear of a dog. Auricle increases the volume of the atrium. The two atria are separated from each other by an internal inter-atrial septum.
Lower chambers: right and left ventricles. They are internally separated from each other by interventricular septum. The irregular ridges and folds of the myocardium of the ventricles are called trabeculae carneae.
Chambers separated internally by septum
External separations by:
Coronary sulcus: separates atria and ventricles
Anterior and posterior Interventricular sulci: separate ventricles

11. The Great Vessels of the Heart
Right atrium receives blood from all parts of the body except the lungs. It receives this blood through three veins: superior/anterior vena cava( brings blood from upper parts of the body, head, neck, and arms), inferior vena cava/posterior vena cava( brings blood from the lower parts of the body, legs and abdomens)
Coronary sinus: drains blood from most of the vessels that supply the walls of the heart with blood.

13. The Great Vessels of the Heart (cont’d.)
The right ventricle pumps the blood into pulmonary trunk which splits into the right pulmonary artery and the left pulmonary artery, which carry the blood to the lungs.
They carry deoxygenated blood to lungs.
Pulmonary veins (four): return oxygenated blood to heart/left atrium. Then the blood is squeezed into the left ventricle.
Ascending aorta: carries oxygenated blood out to body, and to the coronary arteries ( which supply the walls of the heart with oxygenated blood), the arch of the aorta( which sends arteries to upper parts of the body). Descending thoracic aorta which becomes abdominal aorta.

15. The Valves of the Heart Atrioventricular Tricuspid (three cusps)
Between right atrium and right ventricle
Bicuspid (two cusps)/atrioventricular valve/mitral valve
Between left atrium and right ventricle
Cusps attach to ventricles by chordae tendineae

16. The Valves of the Heart (cont’d.)
Semilunar valves
Pulmonary semilunar valve
Right ventricle
Pulmonary trunk exits the heart
Aortic semilunar valve
Left ventricle
Ascending aorta leaves the heart

17. The Valves of the Heart (cont’d.)

18. Blood Flow through the Heart

19. Blood Flow through the Heart (cont’d.)
Deoxygenated blood enters right atrium via superior/inferior vena cava and coronary sinus.
Deoxygenated blood returns from body to right atrium
Sent to right ventricle passing tricuspid valve, which pumps blood to lungs via pulmonary trunk passing the pulmonary semilunar valve.
Left/right pulmonary arteries go to lungs to get oxygenated and return to heart in left atrium via left/right pulmonary veins.
Oxygenated blood returns to left atrium

20. Blood Flow through the Heart (cont’d.)
Sent to left ventricle passing the bicuspid/mitral valve.
Left ventricle sends blood to the body via the ascending aorta passing the aortic semilunar valve.

21. Blood Flow through the Heart (cont’d.)

22. The Conduction System of the Heart

23. The Conduction System of the Heart (cont’d.)
Sinoatrial (SA) node: pacemaker; initiates impulse 
Atrioventricular (AV) node: sends impulse to AV bundle 
Bundle of His: sends impulses to both sides of system 
Purkinje’s fibers: send impulse to myocardial cells

24. The Conduction System of the Heart (cont’d.)

25. A Cardiac Cycle

26. A Cardiac Cycle (cont’d.)
One cycle
Atria contract / ventricles relax
Ventricles contract / atria relax
Systole: contraction phase
Diastole: relaxation phase

27. Some Major Blood Circulatory Routes

28. Some Major Blood Circulatory Routes (cont’d.)
Systemic circulation
All blood leaving left ventricle (oxygenated)
All blood returning to right atrium (deoxygenated)
Pulmonary: blood flow to lungs for gas exchange

29. Anatomy of Blood Vessels

30. Anatomy of Blood Vessels (cont’d.)
Arteries and veins have three layers
Tunica intima: innermost layers( endothelial cells)
Tunica media: middle layer( smooth muscle)
Tunica adventitia: outer layer( connective tissue)
Lumen: blood vessel cavity( blood flows)
Anastomosis: junction of blood vessels

31. Anatomy of Blood Vessels (cont’d.)
Arteries: thicker and stronger than veins in elasticity and contractility.
Arterioles: small arteries attach to capillaries
Capillaries:. gas nutrient and waste exchange.Microscopic vessels made of simple squamous epithelial cells, one cell layer thick, called endothelium.
Venules: connect capillaries to veins
Veins: Has same three coats as arteries but more connective tissue ,with less elastic than arteries, contain valves( blood flow in one direction toward the heart)

32. Anatomy of Blood Vessels (cont’d.)