Respiration system

• Respiratory system


  The system responsible for breathing
• Inhalation


  Breathing in
• Exhalation


  Breathing out
• Respiratory system


  • Takes in oxygen from the atmosphere
  • Gives out carbon dioxide and water vapour to the atmosphere
• Breathing


  1. Inhalation

  2. Exhalation
• Air enters the respiratory system through the mouth and nose
• Nose


  • Warms and moistens air
  • Removes dust and micro-organisms with hairs and mucus
• Epiglottis


  A flap of tissue that stops food from going down the 'wrong way' and entering the trachea
• Trachea


  The windpipe, made from c-shaped rings of cartilage that keep it open
• Trachea


  Allows air to flow to the bronchus
• Bronchus


  Allows air to flow into and out of the lungs
• Lungs


  Two large, spongy, elastic organs located in the chest cavity that expand and contract during breathing
• Bronchioles


  Increasingly narrow tubes in the lungs that the bronchus divides into
• Alveolus


  Tiny air sac at the tip of each bronchiole where gas exchange between blood and air takes place
• Gas exchange in alveoli

  1. Oxygen moves from alveoli to capillaries

  2. Carbon dioxide and water move from capillaries to alveoli
• Diffusion


  Allows gases to move from high to low concentration
• Alveoli and capillaries


  • Have very thin walls (one cell thick) to allow easy gas exchange
• There are millions of alveoli in the lungs
• Diaphragm


  Large sheet of muscle below the lungs that contracts and flattens to bring air in, and relaxes to force air out
• Intercostal muscles


  Move the ribs during inhalation and exhalation
• Digestive system and circulatory system


  Food is broken down and absorbed into the bloodstream
• Digestive system and respiratory system

  The pharynx is the opening for both systems, the epiglottis stops food entering the trachea, and mucus traps dust and micro-organisms
• Circulatory system and respiratory system

  The pulmonary artery takes deoxygenated blood to the lungs, diffusion allows gas exchange at the alveoli, and the pulmonary vein carries oxygenated blood back to the heart
• Key terms


  • inhalation
  • exhalation
  • trachea
  • bronchus
  • lungs
  • alveolus
  • diffusion
  • diaphragm
  • intercostal muscles
• respiratory system diagram

  A) nasal cavity

  B) epiglottis

  C) trachea

  D) right lung

  E) right bronchus

  F) bronchioles

  G) diaphragm

  H) inter costal muscles

  I) alveolus

  J) alveoli

  K) ribcage

  L) left bronchus

  M) left lung