Smoking

• cilia sweep mucus towards the trachea --> to be coughed up
• Mucus = sticky (to trap dust, bacteria, viruses, etc)
• cilia - specialised cell - has lots of mitochondria to do respiration (ATP produced is used to sweep)
• These are cilia

  
• smoking clogs up mucus (no longer sticky), temporarily paralyses cilia so they can no longer sweep ---> bacteria goes into lungs ---> could cause diseases
• nicotine = addictive --> smoking is addictive
• Diseases caused = emphysema + cancer
• emphysema = walls of alveoli break down (surface area is reduced) --> gas exchange is greatly reduced --> sufferers constantly out of breath
• Emphysema = break down of alveoli walls
• This is emphysema

  
• Cancer is caused by carcinogens such as tar
• carcinogens = cancer-causing chemicals
• In a graph conveying cancer + cigarette use, a delay = cancer takes a long time to develop