the heart and blood vessels

• Double circulator system


  Made up of heart, blood vessels and blood

  Two circuits joined together
• Structures of heart


  Right (deoxygenated):

  Vena cava

  Right atrium

  Right ventricle

  Pulmonary Artery

  
  

  Left (oxygenated)

  Pulmonary Vein

  Left atrium

  Left Ventricle

  Aorta

  
  

  R - VAVA VAVA - L (acronym)
• Pulmonary


  Related to lungs (away from/towards)
• Veins


  Carry blood towards the heart
• Arteries


  Carry blood away from heart
• Pacemaker


  A group of cells located in the right atrium that sends out signals that make the heart muscle contract and that regulates heart rate.
• Artificial pacemaker


  A device implanted under the skin, provides an electrical current to keep the heart beating regularly
• Features of arteries


  Arteries carry blood from the heart to the rest of the body.

  Blood is carried under high pressure.

  Thick, muscular walls (smooth muscle) with elastic tissue to expand and recoil

  Narrow lumen - maintain high pressure

  All arteries carry oxygenated blood except for the pulmonary arteries, which take deoxygenated blood to the lungs.
• Features of capillaries


  Arteries branch into capillaries

  Really small

  Carry blood close to every cell to exchange substances

  Permeable wall, aid diffusion

  Supply food and oxygen, remove waste and CO2

  Walls one cell thick, decreases diffusion distance
• Veins


  Blood vessels that carry blood back to the heart

  Capillaries join up to form veins

  Low pressure blood

  Wider rumen to help blood flow

  Contain valves to prevent back flow of blood (keep blood flowing the the correct direction)
• Calculating rate of blood flow

  Rate of blood flow = volume of blood / number of minutes
• Double circulatory system

  1. Right ventricle pumps deoxygenated blood to the lungs to take in oxygen

  2. Blood returns to the heart

  3. Left ventricle pumps oxygenated blood around all other organs of the body

  4. Blood gives transfers its oxygen to the blood cells

  5. Deoxygenated blood is pumped back to the lungs
• Heart

  • Walls are mostly made of muscle tissue
  • Has valves to prevent backflow
• Deoxygenated blood flow

  1. Flows through the Vena Cava into the Right Atrium

  2. Atria contracts, pushing the blood into the Right Ventricle

  3. Ventricle contracts, forcing the blood into the pulmonary artery and out of the heart

  4. Transported by arteries to lungs
• Oxygenated blood flow

  1. Flows through the Pulmonary Vein into the Left Atrium

  2. Atria contracts, pushing blood into the Left Ventricle

  3. Ventricle contracts, forcing the blood into the aorta and out of the heart

  4. Transported by arteries around the body
• Coronary arteries

  • Branch off the aorta and surround the heart, supplying it with oxygenated blood
• Resting heart rate control

  1. Group of cells in the right atrium wall act as a pacemaker

  2. Produce a small electrical impulse which spreads to the surrounding muscle cells causing them to contract