2.7.6 Smoking & the Human Gas Exchange System Flashcards
What diseases does smoking cause?
Smoking causes chronic obstructive lung disease (COPD), coronary heart disease and increased risks of several different types of cancer, including lung cancer
What 3 main chemicals are found in cigarettes?
1. Tar – a carcinogen (a substance that causes cancer)
What are the 3 main effects of Nicotine?
1. Nicotine narrows blood vessels leading to an increased blood pressure
What does Carbon monoxide do?
Carbon monoxide binds irreversibly to haemoglobin, reducing the capacity of blood to carry oxygen
What are some side effects of Carbon Monoxide
1. puts more strain on the breathing system as breathing frequency and depth need to increase in order to get the same amount of oxygen into the blood
What is Tar
Tar is a carcinogen and is linked to increased chances of cancerous cells developing in the lungs
What does Tar contribute to?
It also contributes to COPD, which occurs when chronic bronchitis and emphysema (two different diseases which are frequently linked to smoking) occur together
Give a description of Chronic bronchitis
Chronic bronchitis is caused by tar which stimulates goblet cells and mucus glands to enlarge, producing more mucus
- It destroys cilia and mucus (containing dirt, bacteria and viruses) builds up blocking the smallest bronchioles and leading to infections
- A smoker’s cough is the attempt to move the mucus
Emphysema develops as a result of, what?
frequent infection, phagocytes that enter the lungs release elastase, an enzyme that breaks down the elastic fibres in the alveoli
an enzyme that breaks down the elastic fibres in the alveoli results in what?
the alveoli become less elastic and cannot stretch so many burst
The breakdown of alveoli reduces the surface area for gas exchange
As it progresses, patients become breathless and wheezy – they may need a constant supply of oxygen to stay alive
The breakdown of alveoli in emphysema reduces the surface area for, what?
gas exchange
