What is it???? This muscle never stops working… It works when you are asleep… It works when you eat… It really works when you exercise…. What is it????

The HEART Located between the lungs in the mid thoracic region Surrounded by a membrane called the pericardium Apex points toward the left hip Composed of cardiac muscle tissue

Atrioventricular valves = Tricuspid, Mitral, The chambers: Left & Right Atria Left & Right Ventricles The vessels: Pulmonary artery & vein Superior & inferior vena cava Aorta The valves: Atrioventricular valves = Tricuspid, Mitral, Semilunar valves = Pulmonary & Aortic

Right and left are based on the position of the heart within the body Right and left are based on the position of the heart within the body. Even tho the right atrium and right ventricle are on the left as you look at them, they are on the right side of the heart as it is sitting in the person’s chest. The tricuspid valve and the bicuspid valve also known as the mitral valve have tendons that help them open and close. They are the Chordae tendineae sometimes referred to as the heart strings. As the muscle contracts and releases the tendons pull on the flaps that make up these valves opening and closing them.

Allow blood to flow in only one direction The Valves Allow blood to flow in only one direction The pulmonary semilunar valve is the doorway between the right ventricle and the pulmonary artery which carries “dirty” blood to the lungs The aortic semilunar valve is the doorway between the left ventricle and the aorta which carries “clean” blood to the body

The tricuspid valve separates the right atrium and right ventricle The Valves Allow blood to flow in only one direction The tricuspid valve separates the right atrium and right ventricle Composed of 3 flaps The mitral valve (sometimes called the bicuspid valve) separates the left atrium and left ventricle Composed of 2 flaps Valves open as blood is pumped through Held in place by chordae tendineae (“heart strings”)

Aorta leaves left ventricle Superior vena cava enters right atrium Pulmonary artery leaves right ventricle Rt Pulmonary veins enters left atrium L Pulmonary veins enters left atrium Inferior vena cava enters right atrium

The Vessels Superior Vena Cava Inferior Vena Cava Pulmonary Veins Carry deoxygenated blood from the upper and lower parts of the body into the heart Pulmonary Veins Carry oxygenated blood from the lungs to the heart Pulmonary Arteries Carry deoxygenated blood from the heart to the lungs Aorta Carries oxygenated blood from the heart out to the body Remember that veins ALWAYS carry blood TO the heart and arteries ALWAYS carry blood AWAY from the heart. However veins don’t ALWAYS carry dirty blood and arteries don’t Always carry clean blood. Note the pulmonary vein coming To the heart from the lungs with oxygenated blood and the pulmonary artery carrying deoxygenated blood away from the heart to the lungs.

Cardiovascular System A DOUBLE PUMP system Pulmonary Circuit RA  RV  Pulmonary artery  capillary beds of the alveoli Systemic Circuit capillary beds of the alveoli  LA  LV Aorta  Body Functions to deliver oxygen and nutrients and to remove carbon dioxide and other waste products The heart is called a double pump because it serves two circulations. The pulmonary circuit is a loop that take deoxygenated blood to the lungs for oxygenation The systemic circuit is a loop that takes the oxygenated blood to the body, drops off the oxygen and picks up carbon dioxide and wastes

Blood flow thru the Human HEART Oxygen-poor blood (shown in blue) flows from the body into the right atrium. Blood flows through the right atrium into the right ventricle. The right ventricle pumps the blood to the lungs, where the blood releases waste gases and picks up oxygen. The newly oxygen-rich blood (shown in red) returns to the heart and enters the left atrium. Blood flows through the left atrium into the left ventricle. The left ventricle pumps the oxygen-rich blood to all parts of the body.

If you listen to your heartbeat, it makes a lub dub sound. The lub is when blood is pushed out of the heart into the body and the dub is the reloading of the heart with more blood ready to push it out to the body

Hold out your hand and make a fist Hold out your hand and make a fist. If you're a kid, your heart is about the same size as your fist, and if you're an adult, it's about the same size as two fists. Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times. Heart Facts Give a tennis ball a good, hard squeeze. You're using about the same amount of force your heart uses to pump blood out to the body. Even at rest, the muscles of the heart work hard--twice as hard as the leg muscles of a person sprinting. The human heart can create enough pressure that it could squirt blood at a distance of thirty feet. Scientists have discovered that the longer the ring finger is in boys the less chance they have of having a heart attack.

COMPOSITION BOOK Cut out diagram of heart Label the major vessels Label the chambers Label the valves Color the areas of deoxygenated blood blue Color the areas of oxygenated blood red Answer the following questions in complete sentences on the page below your diagram Why is the cardiovascular system referred to as a “double pump” system? Where does the systemic circuit go? What is the name of the circuit that is responsible for oxygenating the blood?