respiratory system

• Respiration


  The release of energy from food
• Respiratory system


  Provides oxygen to the body so respiration can occur
• Alveolus


  • Adapted for gaseous exchange because it is only one cell thick, has a large blood supply, and large surface area
• Breathing in


  1. Intercostal muscles contract, causing ribs to move up and out

  2. Diaphragm contracts, causing it to move down

  3. These steps increase the volume of the ribcage

  4. The pressure in the lungs decreases

  5. Air is sucked in
• Breathing out


  1. Intercostal muscles relax, causing ribs to move down and in

  2. Diaphragm relaxes, causing it to arch up

  3. These steps decrease the volume of the ribcage

  4. The pressure in the lungs increases

  5. Air is forced out
• Oxygen from air in the alveoli


  Needs to enter the bloodstream
• How the organs of the respiratory system interact with organs of the circulatory system

  1. Blood is pumped by the heart through the pulmonary artery to the lungs

  2. The artery divides into tiny capillaries that surround each alveolus

  3. The oxygen can now move across the membrane of the alveolus and enter the blood

  4. Once oxygen is in the capillaries, they rejoin to form the pulmonary vein

  5. This blood returns to the heart to be pumped around the whole body
• The trachea and oesophagus meet in the throat in a region called the pharynx


  • If you cough up mucous from your trachea, it usually goes down the oesophagus to get rid of it
  • Acid in the stomach will then kill any bacteria that may be in the mucous
  • The epiglottis is a flap that covers the trachea when we swallow
  • The epiglottis stops food going down the wrong way
• Environmental factor affects breathing

  • Smoking damages health by:
  • Clogging hairs in the nose
  • Increasing mucous in the breathing system
  • Increasing the risk of lung infections cancer
  • Increasing the risk of heart attacks
  • Damaging the growth of a baby in the womb
• Parts of the respiratory system

  • Trachea
  • Voice box
  • Rings of cartilage
  • Alveoli
  • Diaphragm
  • Bronchiole
  • Bronchus
• Exercise


  Increases the rate of breathing in order to supply extra oxygen and remove the extra waste products formed during increased respiration