The Heart

• what does the heart do

  pump blood around the body in a double circulatory system
• what does a double circulatory system mean

  heart pumps blood through TWO circuits
• what happens in each circuit

  • in one circuit -> heart pumps DEOXYGENATED blood to lungs to become OXYGENATED
  • in second circuit -> OXYGENATED blood pumped to rest of body to supply cells with oxygen
  • then deoxygenated blood returns back to heart
• describe the double circulatory system 


  .

  
• how many chambers is the heart made up of

  4
• name the 4 chambers

  • right atria
  • left atria
  • right ventricle
  • left ventricle
• what are the 4 amour blood vessels

  • aorta
  • vena cava
  • pulmonary artery
  • pulmonary vein
• what does the pulmonary artery do

  take blood AWAY from heart
• what does the pulmonary vein do

  brings blood back TO heart
• what is the role of the aorta

  blood's main artery
• what does the vena cava do

  brings blood BACK to heart from BODY
• why is the left ventricle have much thicker walls

  • pumps blood to rest of the body
  • needs to travel further
• what do valves do

  • prevent black flow of blood
  • travels in 1 direction
• label the heart 


  .

  
• do the atria contract at the same time 


  yes
• do the ventricles contract at the same time 


  yes
• what's happening on the left hand side

  • oxygenated blood from LUNGS enters heart through pulmonary vein -> left atrium
  • oxygenated blood travels from left atrium -> left ventricle
  • which then travels from left to left ventricle -> aorta -> pumped to rest of the body
• what's happening on the right hand side

  • deoxygenated blood from BODY enters through vena cava -> right atrium
  • deoxygenated blood travels from right atrium -> right ventricle
  • which then travels from right ventricle -> pulmonary artery -> pumped to lungs
• what's the cardiac output

  total volume of blood pumped out by left ventricle every minute
• how do you calculate the the cardiac output

  cardiac output = stroke volume x heart rate

  cm^3 per min = cm^3 per beat x bpm
• what's the pulse

  heartbeat per minute
• what happens when we exercise more

  • respire more
  • so cardiac output must increase for our cells to be supplied with more oxygen + more glucose
  • more energy will be released
• explain the changes in cardiac output during exercise

  • more respiration -> more CO2 produced
  • so cardiac output increases to remove CO2
  • to ensure more aerobic respiration takes place
  • preventing build up of lactic acid