1. The Heart

2. Membranes Pericardium Covers the heart Visceral – innermost layer
Parietal – outermost layer
Pericardial fluid: serous fluid found between visceral & parietal layers reduces friction

3. Heart Wall Epicardium (visceral pericardium): outer covering
Myocardium: cardiac muscle tissue
Endocardium: epithelial & connective tissue; continuous with inner linings of blood vessels attached to heart

4. Heart Parts

5. A: Superior Vena Cava
B: R. Pulmonary Artery
C: R. Pulmonary Vein
D: R. Atrium
E: Tricuspid Valve
F: R. Ventricle
G: Inferior Vena Cava
H: Myocardium (Septum) I: L. Ventricle J: Bicuspid Valve K: Pulmonary Valve L: L. Atrium M: L. Pulmonary Vein N: Pulmonary Trunk O: Aorta

6. Chambers
Atria (right & left): thin walls, upper chambers; receive blood returning to the heart
Ventricles (right & left): lower chambers; receive blood from atria, contract to force blood into arteries
Septum: divides heart into right & left sides

7. Valves
2 Artioventricular (AV) valves: prevent backflow of blood into atria
Tricuspid valve: between RA & RV
Bicuspid Valve: between LA & LV
Chordae tendineae = fibrous strings that attach from papillary muscles to valve; open valves
Papillary muscles = small mounds of cardiac muscle tissue
Aortic valve: prevents backflow of blood into L ventricle from aorta
Pulmonary Valve: prevents backflow of blood into R ventricle from pulmonary trunk

8. Essential Blood Vessels
Pulmonary trunk: divides to form R/L pulmonary arteries, which carry blood into lungs from R ventricle
R/L pulmonary veins: carry blood from lungs to L atrium
Aorta: large artery, carries blood away from heart to body

9. Blood Flow pattern

10. Khan Academy Video:
Fetal Heart