Heart

• Artery

  • Small lumen
  • High pressure
  • Thick elastic fibres - expansion
  • Smooth muscle - strong
• Capillary

  • One cell thick wall
  • low pressure
  • very small lumen
  • large surface area
• Veins

  • Large lumen - enable flow of blood under low pressure
  • Thin layer of muscle/elastic
  • Valves - prevent backflow
  • Low pressure
• Why might a clot that blocks the small blood vessels in the lungs cause death?

  No oxygen -> no respiration
• How does having more red blood cells make it an advantage to athletes who take part in long distance races?

  • More oxygen -> haemoglobin
  • Less anaerobic respiration -> less lactic acid
  • More energy -> run faster
• Septum 


  Separate right/left side of heart
• Vena Cava

  • Vein
  • De-oxygenated blood
  • From body to right atrium
• Pulmonary artery

  • Artery
  • De-oxygenated
  • From right ventricle to lungs
• Pulmonary vein

  • Vein
  • Oxygenated
  • From lungs to left atrium
• Aorta

  • Artery
  • Oxygenated
  • From left ventricle to body
• Hepatic


  Liver
• Renal


  Kidney
• Pulmonary 


  lungs
• Hepatic vein


  De-oxygenated blood from liver to heart
• Hepatic artery


  Oxygenated blood from heart to liver
• Renal artery


  Oxygenated blood from heart to kidney
• Renal vein


  Deoxygenated blood from kidney to heart
• Hepatic portal vein


  Oxygenated blood from stomach to liver
• How does narrowing of arteries affect the ability of the heart to function?

  Less oxygen -> more anaerobic respiration

  More lactic acid

  Increase in heart rate

  Increase in pressure

  Heart attack
• Gas exchange 


  Where oxygen is taken in and carbon dioxide is expelled
• Double circulatory system

  • Two routes
  • heart -> lungs -> heart
  • heart -> body -> heart
• Adrenaline

  • Adrenal glands
  • Increases HR and BR
  • Flight or fight
• Insulin

  • Pancreas
  • Controls level of glucose in blood
  • Lowers glucose concentration in blood
• Testosterone

  • Testis
  • Puberty in boys
  • Deeper voice/muscle size increases
• Progesterone

  • Ovaries
  • Controls thickness of uterus lining
  • Maintains the lining of uterus
• Oestrogen

  • Ovaries
  • Puberty in girls
  • Bigger breasts/armpit hair
• What happens after you have eaten

  • Insulin is released
  • glucose -> glycogen
  • Lowers amount of glucose in hepatic vein
  • Increases glucose in hepatic portal vein
• What happens after you haven't eaten for a while

  • Insulin stops being released
  • Glucagon turns glycogen -> glucose