Heart and circulatory system

• function of arteries

  • Carry blood away from the heart
• Pacemaker


  Keeps the heart beat regular
• The heart is the organ that pumps blood around your body
• How blood flows through the heart and blood vessels

  1. Blood enters the heart twice

  2. Blood flows through the body

  3. Blood is oxygenated in the lungs

  4. Blood is pumped to the body
• Coronary heart disease (CHD)


  Narrowing of the coronary arteries, normally by build-up of fatty materials such as cholesterol
• Coronary arteries become completely blocked


  Heart muscle doesn't get the glucose and oxygen it needs, leading to a heart attack
• Pacemaker


  Found in the right atrium, sends an electrical signal through the heart, instructing it to beat in a rhythm
• Parts of the heart

  • Atria (where blood collects when it enters the heart)
  • Ventricles (pump blood out of the heart to the lungs or around the body)
  • Septum (separates the right-hand and left-hand side of the heart)
  • Valves (prevent blood flowing in the wrong direction)
• Main blood vessels into and out of the heart

  • Aorta (carries oxygenated blood away from the left ventricle to the body)
  • Vena cava (carries deoxygenated blood from the body back to the heart)
  • Pulmonary artery (carries deoxygenated blood away from the right ventricle to the lungs)
  • Pulmonary vein (returns oxygenated blood from the lungs to the heart)
• Types of blood vessels

  • Arteries (carry oxygenated blood away from the heart, have thick and elastic walls)
  • Veins (carry deoxygenated blood back to the heart, have valves)
  • Capillaries (connect arteries to veins, allow maximum diffusion)
• Components of blood


  • Red blood cells (carry oxygen)
  • White blood cells (protect against pathogens)
  • Platelets (help clot blood)
  • Plasma (liquid that suspends the other components)
• Pacemaker


  Keeps heart beat at a rhythm
• Coronary heart disease


  Build-up of fatty materials in the coronary arteries
• fumonary artery


  from Lungs
• Blood components


  • Plasma
  • Red blood cell
  • white blood ce
  • Platelets
• Arteries


  • Oxygenated
  • Have thick wald
  • Maintain high blood pressure
  • Prevent backflow
• Veins


  • Carry deoxygenated blood back towards the heart
  • Have thin walls
  • Have valves to prevent backflow
• Capillaries


  • Narrow
  • Allow substance exchange