Circulatory system

Cards (41)

  • 3 components of the circulatory system are:
    • heart
    • blood vessels
    • blood
  • the role of the circulatory system is to transport substances around the body via the blood.
  • our circulatory system has two loops one that passes through the lungs and one that passes around the body.
  • Because there are 2 loops we call it a double circulatory system.
  • A double circulatory system is good as it allows the pressure in the blood to be increased again before being pumped around the body.
  • the hearts role is to pump blood to the lungs and the body.
  • The heart has 4 chambers:
    • Right atrium
    • right ventricle
    • left atrium
    • left ventricle
  • The pulmonary artery carries blood from the heart to the lungs.
  • The pulmonary vein carries blood away from the lungs.
  • the right side of the heart pumps deoxygenated blood to the lungs.
  • the pulmonary vein carries oxygenated blood to the left atrium.
  • Vena cava - carries deoxygenated blood from the body to right atrium.
  • Pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
  • Pulmonary vein carries oxygenated blood from the lungs to the left atrium.
  • Aorta carries oxygenated blood from the left ventricle to the body
  • The left ventricle has thicker walls as it has to pump blood around the entire body.
  • valves prevent the backflow of of blood.
  • Right side of heart= tricuspid valve
    left side of heart= bicuspid valve
  • Semi-lunar valves are the ones in between the ventricles and the arteries.
  • The route blood takes as it passes around the body
    Vena cava -> right atrium -> right ventricle -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> left ventricle -> aorta -> body -> vena cava
  • Coronary arteries supply the heart muscle with oxygenated blood.
  • Approximate value of resting heart rate is 70bpm
  • Heart rate is controlled by a group of cells in the right atrium which act as a pace maker. They release waves of electrical activity causing the heart muscle to contract rhythmically.
  • The 3 main types of blood vessels are:
    • Arteries
    • capillaries
    • veins
  • Arteries carry blood away from the heart
  • Capillaries exchange substances with the cells of the body.
  • Veins carry blood towards the heart.
  • Veins have valves
  • Arteries are adapted. they have:
    • Thick muscle layer
    • thick elastic layer
    • thick walls
  • capillaries are adapted. they are:
    • one cell thick
    • permeable walls
    • narrow lumen
  • Veins are adapted. they have:
    • wide lumen
    • valves
  • rate of blood flow= vol of blood/time
  • 4 components of blood:
    • red blood cells
    • white blood cells
    • platelets
    • plasma
  • Plasma is yellow liquid that transports substances around the body
  • Nutrients, waste products, antibodies and more are all dissolved in plasma.
  • Red blood cells transport oxygen around the body.
  • Red blood cells are adapted:
    • contain haemoglobin
    • biconcave shape
    • no nucleus
  • white blood cells protect the body from invading pathogens.
  • white blood cells are adapted:
    • some can produce antibodies
    • some can produce antitoxins
    • some can engulf and digest pathogens
  • platelets are small cell fragments which help the blood clot