1. The Heart
Chapter

2. The Heart Is a Double Pump
Delivers Oxygen and nutrients to the tissues
Removes carbon dioxide and waste from the tissues

3. Location and Design
Hollow muscular organ located within the center of the chest in the mediastinum.
60% is located to the left of midline 5”X3.5” approximately the size of a clenched fist.

5. Shape Oval type shape Base - is the top of the heart
Apex - is the bottom of the heart

6. Organ Layers
The heart moves freely and can change its stroke volume (SV) and twist to eject blood friction free.
Pericardium
Surrounds:
Heart
Great vessels

8. 3 Layers of the Heart Muscle
Epicardium
The outer most layer. Is contiguous with the visceral pericardium
Myocardium
The actual muscle of the heart. It is the thickest. Responsible for contraction (more later)
Endocardium
The inner lining of the heart, made of epithelial cells
In contact with the blood in the chambers.

9. Myocardial Muscle Specialized found only in the heart
Striated like skeletal
Electrical properties like smooth muscle

10. Chambers Double pump. Right and left sides. 4 chambers.
2 atria - upper chambers deliver blood to ventricles.
2 ventricles- lower chambers pump blood out of the heart.
The two atria contract together, as do the ventricles
The heart sounds (lub dub) are caused by the closing of the valves

12. Valves of the heart Designed to promote forward flow
Valves close to prevent backflow
Made of fibrous tissue that has grown out of the walls of the heart
2 types:
Atrioventricular (AV) (separate chambers)
Semilunar (separate chamber/vessel)

13. AV Valves
The two valves that separate the atrial chambers are called AV or atrioventricular valves.
The Bicuspid or Mitral valve is between the left atrium and ventricle
Tricuspid is between the right atrium and ventricle

15. Semilunar valves (half moon)
Both arteries that leave the heart have these valves separating them from the ventricles
Pulmonary
Aortic
Are between the two ventricular chambers and the large arteries that carry blood away from the heart.
They each have 3 leaflets