A powerpoint from the OLD syllabus, much is still relevant.
Science Bank 22 (Body Parts): you just need Part 1 – The Lungs (to 5m 20s):
How do the Lungs work? – a three and a half minute TED-Ed lesson:
Gas Exchange – a 3m video on oxygen transport from lungs to cells. The Respiratory System – a 3m 30s video on how the respiratory system works. The Virtual Body – Circulation, Respiration & Breathing (a 19m video).
Respiratory system song:
B6.2 Revision notes
IGCSE Biology: Coursebook, chapter 9, pp. 116 – 119 & 121 – 123
Infographic from the fabulous Compound Interest – just click on it to enlarge.