Smoking- effects of tar and nicotine

the word documents explains about the harmful effects of smoking nad the diseases that it causes- hope this helps :)

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  • Created on: 23-05-11 12:08
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Smoking
ZONERA JAVAID
Tar and breathing
Cigarette contains over 4000 different types of chemical. Many of these are harmful for the
body. Cigarette smoke includes:
Tar (which is a mixture of chemicals)
Carbon monoxide
Nicotine
Tar is a combination of chemicals that settles itself on the lining of the airways and alveoli.
This causes an increase in the diffusion distance at for the oxygen entering the blood and
carbon dioxide leaving the blood. The presence of the different chemicals that are lying on
the alveoli and the airways may cause an allergic reaction. This causes the airways to get
smaller and also restricts the flow of air towards the alveoli.
The tar destroys or disables the cilia to carry out its function. The cilia on the surface of the
airways is paralysed so its unable to move the layer of mucus away and up to the back of
the mouth. The tar also encourages the goblet cells and the mucussecreting glands to
enlarge and release more mucus. This means that virus and bacteria trapped in the mucus
are not removed. They have the ability to multiply in the mucus, and can block the eventually
form a combination of mucus and bacteria bronchioles.
Smokers cough causes damage to the delicate lining of the alveoli. The lining is then replaced
by scar tissues, which are thicker and less flexible. The layer of smooth muscle in the wall of
the bronchioles also thickens. This reduces the lumen of the airway, causing the flow of air to
be restricted.
The infections brought by the frequent presence of the bacteria and viruses will cause the
mucus lining to inflame the lining of the pathways. This causes a damage to the epithelium
cells. This attracts the white blood cells. They have to deal with the pathogenic
microorganisms. The white blood cells have to make their way through the blood and into
the airways. In order to do this, they release enzymes. The enzyme released digest parts of
the lining of the lungs, so that the white blood cells can move through the air spaces. In this
process, the enzyme elastase is used. This damages the elastic tissue in the lining of the lungs.
This has the greatest effect on the small bronchioles and the alveoli. The loss of elastic
reduces the elasticity of the alveolus wall. This means that when we inhale, the alveoli walls
do not recoil to push the air out.
Cigarette contains large amounts of carcinogenic compounds, those that lead to cancer.
Benozopyrene is one of the most harmful substance. These compounds that are present in
the tar line up on the delicate surface of the lungs. The Carcinogenic compounds enter the
cells of the lung tissue. They directly enter the nucleus of the cell and cause a dramatic effect

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The change caused to the cell is called mutation. If
any mutation is caused to the cell, the genes are affected causing the cell to uncontrollable
divide. This is called cancer. Cancer often starts at the bronchi. Lung cancer can often take
2030 years to develop and it can begin to grow before it is discovered.
Diseases linked to cancer
Chronic bronchitis: this is the inflammation of the lining of the airways.…read more

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Nicotine causes the platelets to become sticky. This increases the risk of blood clots
forming.
The stickiness of the platelets caused by nicotine increases the chance of blood
clots. The sensitive membrane that covers the plague is damaged, red blood cells
also stick to the exposed fatty deposits. This blood clot is known as thrombus. A
clot in the artery may stop the blood flow in the artery.…read more

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