Lesson slides

• What is the heart?

  An organ in the human body
• Where is the Heart?

  Located between the two lungs
• What is the heart's job?

  To pump blood around the body
• What is the heart made of?

  The walls of the heart are made of cardiac muscle only found in the heart. It never tires but can't tolerate a lack of oxygen.
• Vena cava

  Deoxygenated blood is carried from the body to the heart via these veins. Blood from the head and upper body in the superior vena cava and blood from the rest of the body in the inferior vena cava
• Where is the blood pumped to from the Vena cavas?

  Into the right atrium and then the right ventrical below
• Where is the blood from the right ventrical pumped to?

  To the lungs via the pulmonary artery
• Through which blood vessels does the oxygenated blood from the lungs get carried back to the heart in?


  The pulmonary veins
• Where is blood from the pulmonary veins pumped into?

  The left atrium then the left ventricle
• What does the aorta do?

  Carry oxygenated blood to the rest of the body from the heart
• What do valves do?

  They stop 'backflow', they stop blood from flowing the wrong way
• What do tendons do?

  They stop the valves from turning inside out
• What is the wall separating the left and right sides of the heart?

  The septum
• Which side of the heart is thicker?

  The left, because it contains more muscle since it has to pump blood around most of the body but the right ventricle only needs to pump blood to the lungs
• Why is the blood in the Vena cava dark red, but blood in the aorta is bright red?

  Haemoglobin is brighter red when carrying more oxygen. Blood in the aorta has just been oxygenated whereas blood in the veins have returned from capillaries in tissues which have removed oxygen
• What is cardiac output?

  The volume of blood pushed through the aorta each minute. Unit in litres/minute
• What is stroke volume?

  Volume of blood pushed into the aorta in each beat. Unit in litres/beat
• What is heart rate?

  Number of times a heart beats in a minute. Unit is bpm
• What is the formula for cardiac output?

  Stroke volume x heart rate = Cardiac output
• What would your workings look like if you wanted to calculate the cardiac output of a heart that pumps out 0.083 litres of blood at 59bpm

  Cardiac output= stroke volume x heart rate = 0.083 x 59 = 4.9 litres/min
• How does exercise affect the heart?

  Regular exercise increases the strength of the heart muscle and ventricle size. Therefore, fitter people often have bigger stroke volumes and their hearts can beat more slowly to achieve the same cardiac output as a less fit person