The respiratory system -- Why do we need oxygen? -- Mouth and nose -- Pharynx and larynx -- Trachea and bronchi -- Airway problems -- Lungs -- Blood supply to the lungs -- Chest investigations -- Chest diseases -- Inside the lungs -- Gaseous exchange -- Asthma -- Lungs and air pollution -- Smoking -- Breathing mechanics -- Breathing control -- Artificial breathing and air supplies -- Respiratory noises -- Breathing emergencies.