1. The heart.

2. Cardiovascular System
Blood
Heart
Blood vessels
Arteries - bring blood away from heart
Veins – bring blood to heart
Capillaries – smallest vessels where oxygen/nurtrient exchange occurs

3. Heart Wall
Located in the mediastinum within the thoracic cavity (pericardial cavity)
Protected by serous membrane called pericardium
Epicardium – forms outermost layer of cardiac wall
Myocardium – composed of cardiocytes
Endocardium – thin layer that covers chambers of heart

5. Myocardium

6. External Anatomy of the Heart
Four chambers  2 ventricles , 2 atria
Atria: “receiving” chambers and return blood from veins
Ventricles: “pumping” chambers and distribute blood to lungs and tissues
Pulmonary circuits  directs deoxygenated blood to lungs
Systemic circuit  takes oxygenated blood to the body

7. Carotid
Brachiocephalic
Subclavian
Vena Cava
Aorta
Pulmonary Arteries
Pulmonary Trunk
Pulmonary Veins
Left Atrium
Semilunar Valves & Aortic Valve
Right Atrium
Bicuspid/Mitral Valve
Tricuspid/AV Valve
Left Ventricle
Right Ventricle

10. Coronary Circulation The heart can NEVER completely rest
It needs to nourish itself
Systemic circulation  coronary circulation: supplies myocardium with oxygen for muscle contraction

11. Left Coronary Artery
Right Coronary Artery
Circumflex Artery
Marginal Artery
Anterior IV Branch
Posterior IV Branch

14. Coronary Circulation cont’d
The arteries are circulating oxygenated blood
Cardiac veins collect the deoxygenated blood from myocardium
Veins merge at the coronary sinus
Empties deoxygenated blood into the right atrium

15. How can the heart contract?
Cardiac muscle tissue is “autorhythmic”
Does NOT need stimulation from nerves
Brain only dictates how fast the heart contracts
Pacemaker  Sinoatrial node (SA node)
Sets the pace by sending an electrical impulse to other nodal cells
SA Node
AV Node

16. Blood Pressure
Pressure of the circulating blood against your vessel walls
Systolic – when heart contracts and pushes through arteries
Diastolic – measures pressure when ventricles are filling up / in between beats
Normal is about 120/80
Hypertension  silent killer