Protecting the Breathing System (Cambridge (CIE) IGCSE Biology)

Protecting the Breathing System: Extended

Extended Tier Only

• The passages down to the lungs are lined with ciliated epithelial cells

• Cilia comes from the Latin for eyelash, so unsurprisingly these cells have tiny hairs on the end of them that beat and push mucus up the passages towards the nose and throat where it can be removed

• The mucus is made by special mucus-producing cells called goblet cells because they are shaped like a goblet, or cup

• The mucus traps particles, pathogens like bacteria or viruses, and dust and prevents them getting into the lungs and damaging the cells there

Mucus traps particles, dust and pathogens and cilia beat and push it up and away from the lungs