In emphysema the patient becomes breathless because
Correct answer: B. the walls between alveoli break down, reducing the surface area for gas exchange
- A. the trachea is blocked by mucus
- B. the walls between alveoli break down, reducing the surface area for gas exchange
- C. the diaphragm is paralysed
- D. the blood contains too few white cells
Explanation
Smoke attracts phagocytes that release elastase, which digests the elastic tissue, so alveoli merge into large air spaces with much less total surface and the lungs lose the recoil needed to breathe out. Gas exchange falls and expiration becomes an effort, so even mild exertion leaves the patient gasping. The damage is permanent, since alveolar walls cannot regenerate.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Effects of Smoking
Smoking exposes the respiratory system to nicotine, tar and carbon monoxide, damaging cilia, reducing oxygen transport and narrowing or inflaming airways. The topic covers dependence, chronic bronchitis, emphysema, lung cancer and cardiovascular effects, while separating short-term physiological changes from long-term disease.
Practise Respiration
446 free Respiration MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Biology questions like this
Biology is on 8 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Effects of Smoking questions
Lung cancer in smokers is caused mainly by
The component of cigarette smoke responsible for addiction and for raising heart rate and blood pressure is
Carbon monoxide is dangerous because it
The persistent cough of chronic bronchitis in a smoker develops because
Passive smoking is a health hazard because
Asthma is characterized by