the heart and blood

• Where do the ventricles force blood upon contraction?


  aorta and pulmonary artery
• What is the primary function of the human heart?


  To pump blood around the body
• What type of circulatory system does the human heart operate in?


  A double circulatory system
• Which ventricle pumps blood to the lungs?


  The right ventricle
• What occurs in the lungs during blood circulation?

  Gas exchange takes place
• Which ventricle pumps blood around the rest of the body?


  The left ventricle
• What are the main blood vessels associated with the heart?

  • Aorta
  • Vena cava
  • Pulmonary artery
  • Pulmonary vein
  • Coronary arteries
• What controls the natural resting heart rate?

  A group of cells in the right ventricle that act as a pacemaker
• What is the purpose of artificial pacemakers?


  To correct irregularities in the heart rate
• What are the three different types of blood vessels in the body?

  • Arteries
  • Veins
  • Capillaries
• arteries


  CARRY blood away from the heart

  layers of muscles makes artery strong

  elastic fibres allows them to stretch and spring back so they can withstand high pressure

  small lumen
• veins


  low pressure

  valves to prevent backflow of blood in heart

  carry blood TOWARDS the heart

  lumen is wide to allow low pressure blood to go through
• capillaries


  one cell thick=short diffusion distance

  very large lumen

  permeable walls

  supply food and O2 and take away waste products like CO2
• 4 components of blood


  red blood cells

  white blood cells

  plasma

  platelets
• red blood cells


  carry oxygen around the body
• white blood cells


  fight against infection
• platelets


  clot the blood and prevent excessive bleeding
• plasma


  carries substances like CO2 glucose urea hormones products of digestion
• what is coronary heart disease


  the coronary arteries that provide blood to the heart become blocked with the build up of fatty material meaning the heart gets less blood and less oxygen supply
• what are stents 


  stents are metal tubes inserted in arteries keeping artery open to allow blood flow
• advantages of stents


  lower risk of heart attack

  recovery time from surgery is quick
• disadvantages of stents


  risk of heart attack from surgery or infection

  blood clots could form near arteries
• what are statins


  drugs that decrease levels of cholesterol in heart
• advantages of statins


  reduces risk of strokes and heart attacks

  increase levels of good cholesterol
• disadvantages of statins


  need to be taken forever

  doesnt have an immediate effect

  could produce side effects
• what is a faulty valve 


  when a heart valve becomes so stiff that it cannot open or it will leak
• solutions for faulty valves

  replacing it with a biological valve which works well

  BUT only lasts for 12-15 years
• solutions for faulty valve (2)

  replacing it with a man-made valve

  lasts for long time BUT medication needs to be taken so there's no blood clotting around the valve
• heart failure


  solved with heart transplant
• advantages of heart transplant


  less likely to be rejected by immune system
• disadvantages of heart transplant

  mechanical parts could fall out

  blood clots leading to strokes