IGCSE Biology - Smoking

Carboxyhaemoglobin

A compound formed when haemoglobin combines with carbon monoxide in preference to oxygen

Lung cancer

A disease characterised by uncontrolled cell growth in the tissues of the lungs

Emphysema

A lung disease caused when cigarette smoke damages alveoli causing them to become enlarged and inefficient for gas exchange. A person with this disease will suffer breathlessness.

Tumour

A mass of cells that have mutated and divided out of control

Carbon Monoxide

A toxic gas present in cigarette smoke. It can enter the blood from the lungs where it combines with haemoglobin, blocking the blood's ability to carry oxygen to body cells.

Carcinogen

Cancer causing substance or agent

Bronchitis

Inflammation of the mucus membranes of the bronchi. Commonly caused when cigarette smoke paralyses the cilia lining the air passages, preventing mucus being swept away from the lungs.

Nicotine

Strongly addictive drug present in cigarettes

Tar

Toxic matter produced by burning tobacco that can collect in the lungs of smokers