What is the size, location and orientation of the heart?

1. Size of a fist and weighs 250-300 grams
2. Found in the mediastinum and two-thirds lies left of the midsternal line.
3. Base is directed toward the right shoulder and the apex points towards the left hip.

What are the Coverings of the Heart?

1. THE HEART IS ENCLOSED IN A DOUBLED-WALLED SAC CALLED THE PERICARDIUM.

2. DEEP TO THE PERICARDIUM IS THE SEROUS PERICARDIUM.

3.THE PARIETAL PERICARDIUM LINES THE INSIDE OF THE PERICARDIUM.

4. THE VISCERAL PERICARDIUM, OR EPICARDIUM, COVERS THE SURFACE OF THE HEART.

WHAT ARE THE LAYERS OF THE HEART WALL?

1. THE MYOCARDIUM IS COMPOSED MAINLY OF CARDIAC MUSCLE AND FORMS THE BULK OF THE HEART.

2. THE ENDOCARDIUM LINES THE CHAMBERS OF THE HEART.

WHAT ARE THE CHAMBERS AND ASSOCIATED GREATER VESSELS?

1. THE RIGHT AND LEFT ATRIA ARE THE RECEIVING CHAMBERS OF THE HEART.

2. THE RIGHT VENTRICLE PUMPS BLOOD INTO THE PULMONARY TRUNK; THE LEFT VENTRICLE PUMPS BLOOD INTO THE AORTA.

WHAT ARE THE PATHWAYS OF BLOOD THROUGH THE HEART?

THE RIGHT SIDE OF THE HEART PUMPS BLOOD INTO THE PULMONARY CIRCUIT; THE LEFT SIDE OF THE HEART PUMPS BLOOD INTO THE SYSTEMIC CIRCUIT.

CORONARY CIRCULATION?

1. THE HEART RECEIVES NO NOURISHMENT FROM THE BLOOD AS IT PASSES THROUGH THE CHAMBER.

2. THE CORONARY CIRCULATION PROVIDES THE BLOOD SUPPLY FOR THE HEART CELLS.

3 IN A MYOCARDIAL INFRACTION, THERE IS PROLONGED CORONARY BLOCKAGE THAT LEADS TO CELL DEATH.

HEART VALVES?

1. THE TRICUSPID AND MITRAL VALVES PREVENT BACKFLOW INTO THE ATRIA WHEN THE VENTRICLES CONTRACT.

2. WHEN THE HEART IS RELAXED THE AV VALVES ARE OPEN, AND WHEN THE HEART CONTRACTS THE AV VALVES CLOSE.

3. THE AORTIC AND PULMONARY VALVES ARE FOUND IN THE MAJOR ARTERIES LEAVING THE HEART. THEY PREVENT BACKFLOW OF BLOOD INTO THE VENTRICLES.

4. WHEN THE HEART IS RELAXED THE AORTIC AND PULMONARY VALVES ARE CLOSED, AND WHEN THE HEART CONTRACTS THEY ARE OPEN.