Smoking

Cigarettes contains over 4000 chemicals including:

1. Tar
2. Carbon Monoxide
3. Nicotine

The effects of TAR:

1.COPD (Chronic Obstructive Pulmonary Disease)

Chronic emphysema: 

Symptoms: excess coughing, Increasing breathlessness, frequent chest infections, wheezing, fatigue excess mucus, hyperventilating, dizzy, coughing up blood.

It is the breakdown of the alveoli walls due to an elastase enzyme secreted by macrophages which can also cause damage to the elastic fibres. This decreases the surface area, decreasing gaseous exchange

Chronic bronchitis:

Symptoms: inflammation, persistent cough, tight chest, Breathlessness, wheezing

Tar lines the epithelium paralysing and damaging the cilia. The goblet cells react by secreting excess mucus. Due to a mucus build up containing pathogens in the alveoli, bacteria have the ideal conditions (warm and moist) to reproduce. This leads to an infection, large numbers of white blood cells accumulate producing scar tissue reducing the ablility to change the size of the bronchioles.

2. Lung Cancer:

Symptoms: similar to those of emphysema

How to diagnose: CT scan, X-Ray, Spirometer

Tar lines epithelium mutating the DNA turning proto-oncogens into oncogens, tumour suppressor genes stop working leading to uncontrolled cell division and angiogenesis (tumour formation).

The effects of NICOTINE:

• The addictive chemical
• Increases blood pressure and heart rate (damages the endothelium lining of the arteries)
• Stimulates the release of adrenaline from the adrenal glands
• Stimulates the nervous system to reduce the size of the arterioles (reducing the size of the lumen) this can lead to peripheral artery disease (PAD)
• Makes platelets sticky, increasing risk of thrombosis in the coronary arteries

The effects of CARBON MONOXIDE:

• Makes platelets sticky, increasing risk of thrombosis
• Reduces oxygen carrying capacity by binding irreversibly to haemoglobin forming caboxyhaemoglobin
• Damages endothelium of arteries

Atherosclerosis:

Build up of atheroma (fatty deposits) containing cholesterol, transported by low density lipoproteins from the liver to the cells, under the endothelium. Caused by damage to the lining of the arteries by components of tobacco smoke or high blood pressure (caused by nicotine).

Thess fatty deposits can harden to form plaque reducing the size of the lumen, thus reducing the oxygenated blood flow to the heart. If the plaque ruptures a blood clot can form leading to heart attack, heart failure or coronary heart disease (CHD). 

CHD:

Contributing factors: 

- Age
- Diet 
- Obesity
- High cholesterol levels
- High blood pressure

Prevention of smoking strategies:

1) Low nicotine cigarettes:

AGREE: less addicted so fewer smoke 
DISAGREE: smoke more to fulfill nicotine addiction/other harmful chemicals not just nicotine.

2) Education (i.e advertising, pictures and slogans on packets)
3) Government intervention (minimum price)