British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - Cilia definition

Definition: Cilia are hair-like structures that have a waving movement. They line the inside of the lungs along the trachea, bronchi and bronchioles. When oxygen is breathed in, other things get breathed in like dust and microbes. The body recognises those as foreign bodies and makes mucus to trap it and the cilia moves it back up the branches of the lungs to expel it. The mucus is moved to the back of the mouth, where it can either be spat or coughed out or swallowed. This keeps the lungs clean and clear of debris, keeping them healthy.