The Heart and Circulation

• What is a single circulatory system ?

  System with one circuit for blood flow e.g fishs
• What is a double circulatory system ?

  a circulatory system where blood passes through the heart twice and has two separate circuits, one for oxygenated blood and one for deoxygenated blood.
• What is the benefit of the double circulatory system?

  since the blood passes through the heart twice it can travel faster to the body cells deliivering the oxygen needed
• What is the heart ?

  its an organ mainly of muscle tissue
• What does the heart do ?

  its pumps blood around the body
• How many chambers doe the heart have ?

  4 chambers
• What are the names of the 4 chambers in the heart ?

  • at the top there is the left atrium and the right atrium
  • at the bottom there is the left ventricle and the right ventricle
• The atria are separated from the ventricle by valves
• What does the vena cava do ?

  brings in the deoxygenated blood from the body
• Where does the deoxygenated blood go from the vena cava ?

  the blood passes from the heart to the lungs in the pulmonary artery
• What happens in the lungs ?

  the blood collects oxygen (gas exchange )
• What happens in the pulmonary vein ?

  oxygenated blood passes from the lungs to the heart
• What happens in the aorta ?

  oxygenated blood is pumped from the heart to the body
• Where does the blood from the body go ?

  into the left atrium then the right atrium
• What happens when the atria contracts ?

  the blood is forced into the ventricels
• What happens when the ventricles contract ?

  the blood is forced out of the heart
• What does the valves do?

  stops the blood from flowing back into the atria when the ventricles contract
• Why does the left side of the heart have a thicker muscle than the right ?

  the left ventricle pumps the bloods around the entire body so it need to provide greater force
• Where is the coronary artery and what does it do ?

  it branches out of the aorta and spread out into the heart muscle
• What is the purpose of the coronary artery?

  provides oxygen to the muscle cells in the heart
• The oxygen is used in respiration to provide energy for contractions
• The resting heart rate is controlled by a pace maker (in the right atrium)
• What happens when the pacemaker stops working ?

  doctors can make an artificial pacemaker
• What is an artificial pacemaker ?

  a small electrical device and it correct irregularities in heart rate