Reason to Quit Smoking: Pharmacological Aspect
Nicotine appears to be the only pharmacologically active substance in tobacco smoke, apart from carcinogenic tars and carbon monoxide.
EFFECTS ON THE CENTRAL NERVOUS SYSTEM:
The central effect of nicotine is complex and cannot be summed up overall simply in terms of stimulation or inhibition. At the cellular level, nicotine cause neuronal excitation by opening ion channels, exactly as it does in autonomic ganglia and the neuromuscular synapse. It is possible that the overall effect of nicotine effects a balance between activation of nicotine acetylcholine receptors, causing neuronal excitation and desensitization, causing synaptic block. At the spinal level, an inhibition of spinal reflexes occurs and this produces skeletal muscle relaxation.
The peripheral effects of small doses of nicotine result from stimulation of autonomic ganglia and of peripheral sensory receptor, mainly in the heart and lungs. Stimulation of these receptors elicits various autonomic reflex responses, causing tachycardia, increased cardiac output and increased arterial pressure, reduction of gastrointestinal motility and swearing.
An .average cigarette contains about 0.8 g of tobacco and 9-17 mg of nicotine, of which about 10% is normally absorbed by the smoker. This fraction varies greatly with the habits of the smoker and the type of cigarette. Nicotine is the only pharmacologically active constituents of tobacco smoke that is present in sufficient quantity to produce systemic effects. The amount of nicotine absorbed from an average cigarette is about 1.5mg which causes the plasma nicotine concentration to reach 130-200 nmol/lit (20-30 ng/ml).
HARMFUL EFFECTS OF SMOKING:
- Smoking reduces life expectancy. The main health risks are:
- Cancer, especially Lung cancer, of which about 90% of cases are smoking related.
- Ischemic heart disease, both nicotine and carbon monoxide may be responsible.
- Chronic bronchitis, tars are mainly responsible.
- Smoking in pregnancy reduces birth weight and childhood development.
Smoking is a bad habit and causing for various types of diseases. So, we should avoid this habit as soon as possible for our freshness. It is not only the responsibility of government but also responsibility for all to take necessary measures against this habit. So don’t leave it for tomorrow, keep your societies free from smoking for healthy & diseased free life for our next generation.