First 342 words of the document:
What smoking does:
Smoking can lead to several types of problems, specifically lung cancer, chronic bronchitis
and emphysema. Chronic bronchitis and emphysema are generalised a chronic obstructive
pulmonary disorder (COPD).
The main chemicals that contribute to these are tar, carbon monoxide and nicotine.
Tar damages the cilia in the trachea, meaning that the mucus containing all the pathogens will
stay in the lungs and cause infections.
It also blocks alveoli, which means less oxygen can get absorbed as the diffusion pathway is
greater than it should be.
Smoker's cough is when a smoker tries to remove mucus as they haven't got adequate cilia.
Persistent coughing can damage airways and alveoli, and even reduces the lumen size due to
Cigarette smoke contains many carcinogens. Lung cancer is caused by a mutation to a
cells genes that causes uncontrollable growth, leading to tumours. It can take 2030 years
for lung cancer to be discovered.
Chronic bronchitis is the inflammation of the airway linings, damage to cilia and
overproduction of mucus...therefore more lung infections (including things like pneumonia).
Emphysema is the loss of elasticity of alveoli, which means they could burst, therefore
leading to less surface area for gas exchange. People with emphysema will often be short of
breath, wheezy and fatigued.
Effects of nicotine and carbon monoxide:
Carbon monoxide and nicotine can get into the bloodstream, which is why they are extremely
Carbon monoxide binds to haemoglobin of erythrocytes, meaning they cannot carry as much
oxygen per cell.
CO can also damage the endothelium of arteries.
Nicotine cause addiction. It causes the release of adrenaline (FIGHT OR FLIGHT
It mimics neurotransmitters, making the person feel more alert.
Reduces blood flow to extremities (e.g. ears, toes, fingers)
Makes platelets sticky therefore more likely to have a blood clot.
CO damages endothelium of arteries.
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LDLs and cholesterol are deposited under endothelium or in artery wall. (This narrows the
Calcium ions may also be deposited, making the plaque hard. Now blood might clot on the
surface, decreasing the lumen size further.
Damage to the coronary artery that narrows its lumen and therefore reduces blood flow and the
amount of oxygen that can reach the heart muscle.…read more