human circulatory system

• process of blood

  1. blood flows onto right atrium, vena cava ,left atrium though pulmonary vein
  2. atria contract forcing blood into ventricles
  3. ventricles then contract pushing blood into right ventricle into pulmonary artery
  4. taken to the lungs and blood in left ventricle to the aorta to be taken around the body

  valves make sure blood does not flow backwards
• arteries


  carry blood away from heart

  • layers of muscles in walls make them strong
  • elastic fibres allow them to stretch
  • this helps vessels withstand high pressure created by pumping heart
• veins


  carry blood towards the heart

  • lumen is wide so low pressure of blood to flow through
  • have valves to ensure blood flows in right direction
• capillaries


  allow blood to flow very close to cells to enable substance to move between them

  • permeable walls so substance can move across them
  • one cell thick walls create short diffusion pathway
• 4 chamber


  right ventricle , left ventricle , left atrium right atrium
• heart pumps blood in a double circulatory system


  mammals need this cause their metabolic rate is higher

  1.deoxygenate blood ~>right atrium~>right ventricle which pumps it to the lungs to undergo gaseous exchange 2. oxygenate blood flows to left atrium~>left ventricle which pumps oxygenated blood around body
• valves


  make sure blood don’t flow backwards
• coronary arteries


  cover heart to provide own oxygenate blood supply
• red blood cell


  contain haemoglobin

  no nucleus-create space for haemoglobin

  biconcave shape -maximise surface area for oxygen to be absorbed

  flexible -fit through narrow blood vessels
• haemoglobin


  red protein combine with oxygen allow for transport
• plasma


  liquid carries all component of blood
• heart pump blood

  1. blood enter the heart via the atria
  2. once filled with blood atria contract forcing blood down ventricles
  3. when ventricle contract force blood to exit the heart
• aorta


  heart pumps out oxygenated blood to body thru aorta
• coronary arteries


  supply heart muscle with oxygenated blood
• vena cava


  heart recieve deoxygenated blood thru vein called vena cava
• pulmonary vein


  heart reviewed oxygenated blood from lungs through veins
• pulmonary artery


  heart pumps out deoxygenated blood to lungs through artery
• double circulatory system


  right pump sends deoxygenate blood to lungs
• white blood cell

  • can change shape
  • has nucleus
  • defend against infection
• red blood cell

  • biconcave shape
  • large surface area
  • no nucleus


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