CARDIOVASCULAR SYSTEM Transport O2/nutrients/ hormones to cells Remove CO2/wastes

CHARACTERISTICS OF THE HEART: Hollow cone-shaped organ Muscular pump Pumps 7000 liters of blood/day Contracts 2.5 billion X/lifetime Rests on diaphragm Rounded end at bottom: APEX CLOSED SYSTEM of circulation Heart—arteries—arterioles— Capillaries—venules—veins— Back to the heart!

TYPES OF CLOSED CIRCULATION SYSTEMIC CIRCULATION: body PULMONARY: heart to the lungs HEPATIC: through the liver CARDIAC: through the heart (coronary arteries & veins)

LAYERS OF THE HEART: PERICARDIUM: Loose sac surrounding the heart Those that form the wall of the heart: A. EPICARDIUM: (outer) reduces friction B. MYOCARDIUM: thick, cardiac muscle C. ENDOCARDIUM: (inner) elastic

PARTS OF THE HEART: 4 chambers: upper: ATRIA thin walls receive blood RIGHT ATRIA: receive blood from body (through Superior & Inferior VENA CAVA) LEFT ATRIA: receive blood from lungs (through PULMONARY VEINS)   Lower: VENTRICLES Thick walls Pump blood RIGHT VENTRICLE: pumps blood to the lungs (through PULMONARY ARTERIES) LEFT VENTRICLE: pumps blood to body (through AORTA); thicker walls  

Vena Cava Pulmonary Vein Aorta Pulmonary Artery Largest vein SUPERIOR VENA CAVA: brings blood from head, arms, upper body INFERIOR VENA CAVA: brings blood from legs, abdomen Pulmonary Artery Takes blood to lungs from right ventricle Right & Left Only artery to carry unoxygenated blood Pulmonary Vein Brings blood back to heart from lungs 2 right & 2 left Only veins to carry oxygenated blood Aorta Largest artery in body Takes blood from heart to all parts of body 5 branches

Branches of AORTA: Ascending Aortic arch Descending Thoracic Abdominal SEPTUM:  wall separating right side of heart from left

HEART VALVES: Prevent backflow of blood SEMI-LUNAR VALVES: ATRIOVENTRICULAR VALVES: (A-V valves) contain chordae tendinae-pull on papillary muscles between heart chambers Tricuspid Valve: b/w right atria & right ventricle Bicuspid Valve: b/w left atria & left ventricle (also called the mitral valve) SEMI-LUNAR VALVES: (S-L valves) Pulmonary Valve: b/w right ventricle & pulmonary arteries Aortic Valve: b/w left ventricle & aorta

HEART ATTACK MYOCARDIAL INFARCTION Lack of blood supply to heart muscle causes the muscle to die