Heart and circulatory system

• where does oxygenated blood flow

  into the left atrium and then into the left ventricle
• where does deoxygenated blood flow

  into the right atrium and then into the right ventricle
• structure of the heart

  • muscular walls provide a strong heartbeat
  • 4 chambers separate oxygenated blood from deoxygenated blood
  • valves ensure blood doesn't flow backwards
  • coronary arteries cover the heart to provide its own oxygenated blood supply

  
• process of circulatory system

  1. blood flows into the right atrium through the vena cava and left atrium through the pulmonary vein
  2. the atria contract forcing the blood into the arteries
  3. ventricles contract pushing blood in the right ventricle into the pulmonary artery to be taken to the lungs
  4. blood on the left ventricle is pushed into the aorta to be taken around the body
  5. during this, valves close to make sure blood does not flow backwards
• what is the natural resting heart rate

  70bpm
• what are the 3 types of blood vessel

  • arteries
  • veins
  • capillaries
• functions of arteries

  • carry blood away from the heart straight after it has been pumped
  • walls are made of thick, elastic muscle
• function of veins

  • carry blood back to the heart
  • walls are thin, less elastic muscle
• function of capillaries

  • tiny blood vessels that branch out into every tissue in your body carrying substances your cells need like oxygen and glucose
  • thin walls
  • join arteries to veins
• what is the double circulatory system

  blood passes through the heart twice on each loop around the body

  heart -> lungs -> heart -> rest of the body -> heart

  A) pulmonary

  B) vena cava

  C) aorta

  D) pulmonary

  
• what is the gas exchange system made up of

  • trachea (windpipe)
  • intercostal muscles (contract and relax to ventilate lungs)
  • bronchi (air from trachea moves up into these)
  • bronchioles (bronchi split into these and air moves in)
  • alveoli (air sacs where gaseous exchange occurs)
• process of gas exchange

  1. inhalation, alveoli fill with oxygen
  2. blood in capillaries surrounding alveoli is deoxygenated
  3. oxygen diffuses down its concentration gradient into the capillary bloodstream which has now concentration of oxygen
  4. carbon dioxide diffuses down its concentration gradient from the blood to the alveoli
• how are alveoli adapted for gas exchange

  • small and arranged in clusters= large surface area for diffusion
  • capillaries provide large blood supply
  • walls are thin= short diffusion pathways