the heart and lungs

• the lungs are in the...

  thorax
• the thorax is separated from the lower part of the body by the...

  diaphragm
• thorax


  - chest

  - where the lungs are in
• the lungs are protected by the...

  ribcage
• ribcage


  - bones that protect the heart and lungs
• the lungs are surrounded by...

  pleural membranes
• pleural membranes


  - surrounds the lungs

  - provide mechanical protection and a smooth, lubricating elastic surface for the lungs to move during breathing
• the air you breathe in goes though the...

  trachea
• trachea


  - windpipe

  - allows air to pass to and from lungs
• larynx


  - voice box, contains vocal cords

  - passageway for air moving from pharynx to trachea
• pharynx


  - throat

  - passageway for food to the oesophagus and air to the larynx
• the trachea splits into two branches called...

  bronchi
• where does each bronchi go into?

  each lung
• bronchi (singular: bronchus)


  - tubes (right and left) branching off from the trachea and into the lungs
• the bronchi split progressively into smaller tubes called...

  bronchioles
• bronchioles


  - airways in the lungs that lead from the bronchi to the alveoli
• what do bronchioles end in?

  small air sacs called alveoli
• what happens in alveoli?

  gas exchange
• alveoli


  - tiny sacs of lung tissue specialized for the movement of gases between air and blood

  - oxygen diffuses out of the alveolus (high concentration) into the blood (low concentration)

  - carbon dioxide diffuses out of the blood (low concentration) into the alveolus (high concentration) to be breathed out using active transport
• lungs diagram

  
• alveoli diagram

  
• humans have a double...

  circulatory system
• in the first circulatory system...

  - the right ventricle pumps deoxygenated blood to the lungs to take in oxygen

  - the blood then returns to the heart
• in the second circulatory system...

  - the left ventricle pumps oxygenated blood around all the other organs of the body

  - the blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again
• the heart contracts to...

  to pump blood around the body
• veins pump blood ... the heart

  towards
• arteries pump blood ... the heart


  away from
• where does blood enter from in the heart?

  the vena cava and pulmonary vein
• vena cava


  - one of two large vessels (superior and inferior)

  - largest vein in the body

  - returns deoxygenated blood to the right atrium of the heart
• pulmonary vein


  - carries oxygenated blood from the lungs to the left atrium of the heart
• where does blood enter the heart?

  in the atria
• what happens when the atria contract?

  blood flows into ventricles
• atria


  - the two upper chambers of the heart

  - blood flows into into the two atria from the vena cava and pulmonary vein

  - the atria contract, pushing blood onto the ventricles

  - blood flows back into the atria through the veins
• where does blood in the ventricles come from?

  the atria
• what happens when the ventricles contract?

  it forces the blood into the pulmonary artery and the aorta and out of the heart by valves preventing the blooding going back down
• ventricles


  - the two lower chambers of the heart

  - the ventricles contract, forcing the blood into the pulmonary artery and the aorta and out of the heart

  - the blood then flows to the organs through the arteries and returns through the veins
• pulmonary artery


  - carries deoxygenated blood away from the heart to the lungs from the right ventricle
• aorta


  - largest artery in the body

  - carries oxygenated blood from the left ventricle to the rest of the body
• what do valves do to the blood in the heart?

  they prevent the backward flow of blood
• valves


  - flap of tissue in the heart and large veins that prevents blood from flowing backwards

  - this is how the heart uses its four chambers to pump blood around