the heart and circulatory system

• fish have..


  a single circulatory system
• in fish, what happens to the blood from the heart to the gills?

  the blood becomes oxygenated
• in fish, what happens to the blood from the gills to the organs?

  the oxygen diffuses out the blood into the body cells
• in fish, what happens to the blood from the organs to the heart?

  the deoxygenated blood returns back to the heart
• what is the problem with a singular circulatory system?

  • the blood loses a lot of pressure as it passes through the gills before reaching the organs
  • the blood travels to the organs slowly and cannot deliver a good amount of oxygen
• humans have..


  a double circulatory system
• in humans, what happens to the blood from the heart to the lungs?

  the blood becomes oxygenated
• in humans, what happens to the oxygenated blood from the lungs?

  the oxygenated blood returns back to the heart first
• in humans, what happens to the blood from the heart to the organs?

  the blood transfers oxygen to the body cells and becomes deoxygenated
• in humans, what happens to the blood from the organs to the heart?

  the deoxygenated blood returns back to the heart
• what are the benefits of a double circulatory system?

  • passes through the heart twice, therefore the blood can travel rapidly to the body cells
• how many chambers does the heart have?

  four
• the heart..

  is an organ consisting mainly of muscle tissue which pumps blood around the body
• name the 4 chambers of the heart

  • right atrium
  • left atrium
  • right ventricle
  • left ventricle
• the chambers are seperated by..

  valves
• name the four main blood vessels entering and leaving the heart

  • vena cava
  • pulmonary artery
  • pulmonary vein
  • aorta
• the vena cava...

  brings in deoxgenated blood from the body
• the pulmonary artery...

  passes deoxygenated blood from the heart to the lungs
• the pulmonary vein..

  brings oxygenated blood from the lungs into the heart
• the aorta..

  brings oxygenated blood from the heart to the body
• blood enters the heart from...

  the left and right atrium
• blood exits the heart from...

  the left and right ventricle
• where is the vena cava found?

  entering the right atrium
• where is the pulmonary artery found?

  exiting the right ventricle
• where is the pulmonary vein found?

  entering the left atrium
• where is the aorta found?

  exiting the left ventricle
• the atria..

  contracts forcing blood into the ventricles
• the ventricles..

  contract forcing blood out the heart
• the function of the valves?

  to stop blood from flowing backwards
• features of the left ventricle and why

  • has thicker, muscular walls
  • as the left ventricle pumps blood around the whole body and requires a greater force
• the right ventricle only..

  pumps blood to the lungs
• the coronary arteries..

  branch out in the aorta and spread out into the heart muscle
• what is the purpose of the coronary arteries?

  to provide oxygen to the muscle cells of the heart
• oxygen from the coronary arteries..

  is used in respiration to provide the energy for contraction
• natural, resting heart rate is controlled by..

  the pacemaker
• where is the pacemaker found in the heart?

  the right atrium