The effects of smoking on the body


Although tobacco has been accessible worldwide for centuries, the popularity of the intoxicating substance began in England around the late nineteenth century with the introduction of manufactured cigarettes. Until this time smoking was a male orientated pastime. A change in democracy enabled the newly emancipated women to take up the trend of smoking which enraged society as women used cigarettes as a fashion statement. The attraction of smoking rocketed throughout the early twentieth century; with the growing demand for cigarettes further companies emerged and more brands became readily available. Whilst the boom of cigarette production grew pathologists and doctors began to suspect a correlation between cigarette smoking and respiratory diseases. In 1951 Sir Richard Doll and Professor Austin Hill published a report in the British Medical Journal linking cigarette smoking to lung cancer. Over the following years further reports were published which led to manufacturers introducing a range of cigarettes tailored to include lower tar, lower nicotine and filter-tipped cigarettes. The government passed new laws in 1965 to ban all advertising of tobacco products in an attempt to lower the ever-increasing death rate. The following decades produced further laws from health warnings being placed on cigarette packets to tobacco companies being refused to sponsor sport events.


Despite all the government have enforced tobacco manufacturers still do not divulge what cigarettes consist of. Through analysis cigarette smoke is known to contain over four thousand chemicals, at least forty of these are known cancer causing substances. The three constituents which contribute the most unpleasant effects are nicotine, which is a powerful and addictive drug, carbon monoxide, which is the same gas as a cars exhaust projects, and tar, which is an oily substance found in tobacco leaves, this is a known cancer causing chemical.


The process in which these toxic chemicals enter the body starts when the smoker inhales the smoke (see appendix 1) into the mouth towards the trachea which is lined with ciliated epithelium containing goblet cells these secrete mucus, the mucus has two purposes, one is to trap particles and transports them to the buccal cavity where they are swallowed, the other is to moisten the incoming gases. The gas is then projected through the trachea which divides into two bronchi, each of these bronchi are situated in separate lungs, the bronchioles branch throughout the lungs, these are supported by a network of cartilage, the gases are transported through the bronchioles which gradually become narrower, cartilage support decreases and the bronchioles enter the alveoli (see appendix 2 & 3). Surrounding the alveoli are blood capillaries which originate from the pulmonary artery. The gases are then dissolved in the alveolar epithelium and diffuse through them and the endothelium of the blood capillary into the blood stream (see appendix 4). The blood and inhaled gases then travel through pulmonary veins to the heart where they are dispelled through the aorta to journey around the body to all cells and tissues for respiration. The blood and waste products from newly deoxygenised cells travels throughout the body back to the heart where they are redirected to the pulmonary circulation for deoxygenising (see appendix 5).


There are many documented diseases caused by the inhalation of tobacco smoke. From coronary heart disease, cerebral vascular disease, peripheral vascular disease, to cancer of the mouth, voice box, oesophagus, pancreas, and a number of respiratory diseases.


The respiratory system seems to be the biggest casualty of the effects of tobacco. The initial disorder of the lungs is chronic bronchitis, this is caused by the tar in cigarette smoke stimulating the goblet cells to secrete more mucus, as the tar also impedes the cilia that lines the trachea, the sweeping action of the cilia is reduced and removal of the excess mucus is slowed or stopped this leads to build-up of particles that collect and block the bronchioles. Homeostasis is unbalanced and the body reacts by attempting to clear the blockage, this results in a nasty cough, referred to as a “smoker’s cough”. Although not life threatening continual bronchitis leads to epithelia being replaced by scar tissue, and the muscle surrounding the bronchioles and bronchi lose their smoothness and become thicker. The resulting thickening causes the airways to taper therefore difficulty in inspiration and expiration is caused.


If persistent smokers ignore