#53 Summary of Smoking

1 Tobacco smoke contains tar, carbon monoxide and nicotine.

 2 Tar settles on the epithelium lining the bronchi and bronchioles and stimulates inflammation, an increase in the secretion of mucus and an accumulation of phagocytes from the blood.

#52 Cigarette smoking and health

Smoking  is one of the major avoidable  risk factors of chronic,  life-threatening diseases of the gas exchange and circulatory systems.

#51 Summary of Gas exchange

1 Multicellular organisms often have surfaces that are specialised to allow exchange of gases to take place between their bodies and the environment. Alveoli in the lungs form the gas exchange surface in mammals.

#50 The gas exchange system

All organisms take in gases from their environment and release gases to the environment. Animals take in O₂ for aerobic respiration and release CO₂. Plants also respire, but during daylight hours they photosynthesise at a greater rate than they respire, and so take in CO₂ and release O₂.

#49.2 Gas exchange And Smoking Syllabus 2016 - 2018

9.1    The gas exchange system
9.2    Smoking

#49.1 Gas exchange And Smoking Syllabus 2015

• The gas exchange system
• Smoking and smoking-related diseases