Bell work 1/10/13 Which parts of the heart pump blood into the… Pulmonary artery The aorta What do valves prevent? Why does the heart have one side that is more muscular than the other? What side of the heart contains oxygenated blood?

Homework Answers 9.1 The right side of the heart pumps blood to the lungs. Here it absorbs oxygen and is now called oxygenated blood. The gas carbon dioxide is removed from the blood in the lungs. The blood returns to the left side of the heart and from here it is pumped to the body tissues where it gives up its oxygen and is now called deoxygenated blood. It passes back to the left side of the heart in veins.

Homework Answers 9.1 What does double circulation mean. Blood passes through the heart twice during one circuit around the body. Explain the following statements…. Blood on the right side of the heart is at low pressure. Blood on the left side of the heart is at high pressure. Veins contain semi-lunar valves.

9.2 Answers # 1 a) What are the 2 upper chambers of the heart called? Right Atrium & Left Atrium What are the 2 lower chambers of the heart called? Right Ventricle and left ventricle c) What is the function of the septum? Prevents oxygenated and deoxygenated blood from mixing

9.2 Answers #2 A) The atria have less muscular walls than the ventricles. B) The left ventricle has a much more muscular wall than the right ventricle.

9.2 Question #3 Which blood vessel carries: Blood to the rest of the body. Left ventricle Blood from the lungs to the left atrium. Pulmonary vein Blood from the body to the right atrium. Vena Cava Blood to the lungs. Pulmonary Artery Blood under the greatest pressure. Aorta

Circulation / Heart Right Atrium Left Atrium Right Ventricle Left Ventricle Vena Cava Aorta

1. 4. 5. 7. 6. 8. 3. 2. Pulmonary Vein Aorta Pulmonary artery Vena Cava Right Atrium Right Ventricle Left Atrium Left Ventricle 1. 4. 5. 7. 6. 8. 3. 2.

Pulmonary Artery To lungs From Head Vena Cava Semi-lunar valve Right Atrium Vena Cava From Body Tricuspid Valve Right Ventricle Cardiac Muscle

To Head Aorta To body From Lungs Pulmonary Vein Left Atrium Bicuspid valve Tendon Supporting Valve Left Ventricle Septum

Heart action Diastole: is when the heart muscles are relaxed. Systole: is when the heart muscles contract. http://www.youtube.com/watch?v=rguztY8aqpk

Steps in the Pumping Action Atria contract and force blood into the ventricles. Valves between the atria and ventricles open due to pressure of blood against them.

Heart full of blood 3) Then the valves entering the ventricles close.

Contraction 4) Then the ventricles contract to force blood out into the arteries 5) The valves close to prevent blood flowing back into the ventricle.

Pulmonary Artery Right Ventricle Lungs Aorta Left Ventricle Body Vena Cava Deoxygen-ated blood from body Right Atrium Pulmonary veins Oxygenated blood in lungs Left Atrium

Arteries Strong thick elastic walls which can stretch and recoil with the force of blood Blood pulses through arteries as ventricles contract and relax Moves away from the heart. Carries oxygenated blood

Veins Capillaries gradually join up to form veins Blood is at a much lower pressure. Walls are not thick strong and elastic. Lumen is much wider than the lumen of arteries. Have valves that stop blood from flowing backwards. Moves blood back to the heart Carries Deoxygenated blood

Capillaries Estimated that there are over 50,000 miles of capillaries in the body. Give cells nutrients and oxygen and take away waste Very thin, only one cell wide. Blood moves very slowly through it giving time for exchange of substances.