Tobacco cardiovascular system

The actions of nicotine on the central nervous system are the result of a composite of stimulatory and depressant effects. These can include tremors, convulsions, respiratory stimulation or depression, and release of antidiuretic hormone from the pituitary. Nausea and emesis are frequently observed after the initial use of nicotine in the form of tobacco smoke. However, tolerance to these effects rapidly develops. This is in contrast to the effects of nicotine on the cardiovascular system, where tolerance develops much more slowly. 

Cannabis in its various forms is still the most commonly used illicit drug in most countries. In the US, more than 50% of young adults report the use of this drug on some occasion, but it would appear that its casual use has declined among young people in that country from 37% in 1978 to about 18% 10 years later. Despite statements from the advocates for its decriminalization, there is evidence that the smoke from the dried leaves contains potential carcinogens, together with carbon monoxide, and is therefore liable to affect the respiratory and cardiovascular systems adversely, in a similar manner to tobacco. 

Tobacco smoke includes 4000 chemical species with varying potential which cause adverse effects. Nicotine is stimulating to the autonomic nervous system ganglia and neuromuscular junction. The most prominent effects relate to stimulation of the adrenal medulla, central nervous system (CNS), cardiovascular system (release of catecholamines), gastrointestinal tract (parasympathetic stimulation), salivary and bronchial glands, and the medullary vomiting center. There is subsequent blockade of autonomic ganglia and the neuromuscular junction transmission, inhibition of catecholamine release from the adrenal medulla, and CNS depression. 

Relatively few studies have been carried out on the toxic effects of chemical mixtures on the cardiovascular system. The research that has been published addresses the effects of nonspecific mixtures, including landfill leachates, air pollution, and tobacco smoke. These are discussed in the next three sections. 

Tobacco exposure is toxic to the cardiovascular system, even at low levels, in all forms, including 49 ... 

The cardiovascular system is adversely impacted by many single chemicals and also by mixtures. The mixtures most toxic to the cardiovascular system are polluted air and tobacco smoke, mixtures for which relationships are so well defined that predictions can be made mathematically on the number of exposed individuals who will be impacted by cardiovascular disease following exposure. 

Precautions An alkoloid (group of nitrogenous organic compounds, mostly used as pain relievers such as cocaine, quinine, caffeine) from tobacco. A deadly human poison. A human teratogen (abnormal fetal development) by swallowing, causes developmental abnormalities of the cardiovascular system. Causes blood pressure effects. Can be absorbed by intact skin. 

Nicotine is present in varying amounts in all forms of tobacco smoke. Following its absorption from the lungs, the blood nicotine levels are sufficient to cause stimulation but not blockade of nicotinic receptors. In addition to stimulating receptors on autonomic ganglia, ah other nicotinic receptors mentioned earlier can be activated. Thus, tobacco smoking stimulates the cardiovascular, respiratory, and nervous systems. 

The clinical manifestations of PAD are associated with reduction in functional capacity and quality of life, but because of the systemic nature of the atherosclerotic process there is a strong association with coronary and carotid artery disease. Consequently, patients with PAD have an increased risk of cardiovascular and cerebrovascular ischemic events [myocardial infarction (Ml), ischemic stroke, and death] compared to the general population (4,5). In addition, these cardiovascular ischemic events are more frequent than ischemic limb events in any lower extremity PAD cohort, whether individuals present without symptoms or with atypical leg pain, classic claudication, or critical limb ischemia (6). Therefore, aggressive treatment of known risk factors for progression of atherosclerosis is warranted. In addition to tobacco cessation, encouragement of daily exercise and use of a low cholesterol, low salt diet, PAD patients should be offered therapies to reduce lipid levels, control blood pressure, control blood glucose in patients with diabetes mellitus, and offer other effective antiatherosclerotic strategies. A recent position paper... 

Tobacco smoke has considerable adverse effects on the cardiovascular and digestive systems, and is the cause of many cancers (Fig. 5.207). This holds for both, smokers and passive smokers. It is estimated that smoking shortens the lifespan on average by around 10 years. Around half ofthe 1.25 biUion smokers worldwide die from diseases, which are associated with this addiction. 

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