Lesson objectives:

• State that tobacco smoking cans cause-Emphysema, bronchitis, cancer and heart disease.
• Describe how cigarette smoke affects ciliated epithelial cells and how this is linked to “smoker’s cough”

Facts

•     Smokers who smoke between 1 and 14 cigarettes a day have eight times the risk of dying from lung cancer compared to non-smokers.  Smokers who smoke more than 25 cigarettes a day have 25 times this risk compared to non-smokers.
•       Smoking leads to an earlier menopause: on average women smokers go through the menopause up to 2 years earlier than non-smokers and are at a greater risk of developing osteoporosis. Smoking has been associated with increased sperm abnormalities and with impotence in men. 
•     Giving up smoking can reduce the risk of developing many of these problems.  Within 10-15 years of giving up smoking, an ex-smoker's risk of developing lung cancer is only slightly greater than that of a non-smoker.  A young smoker suffering from bronchitis or emphysema who gives up may see some improvement in lung function as a result: damage to lungs caused by years of smoking is permanent but quitting smoking prevents it worsening.
•    It is estimated that several hundred cases of lung cancer and several thousand cases of heart disease in non-smokers in the UK every year are caused by passive smoking.
•     Tobacco use kills around 120,000 people in the UK every year, about 330 every day - as if a plane crashed every day and killed all its passengers,  around 20% of all deaths.
•     Smoking causes at least 80% of all deaths from lung cancer, around 80% of all deaths from bronchitis and emphysema and around 17% of all deaths from heart disease. About half of all regular cigarette smokers will eventually be killed by their habit.

Diseases

•     We are going to look at the main types of diseases which you can get from smoking, which are:
•    Bronchitis
•  Emphysema
• Heart disease
•  cancer

Bronchitis

      Chronic bronchitis is a chronic inflammatory condition in the lungs that causes the respiratory passages to be swollen and irritated, increases the mucus production and may damage the lungs. The symptoms are coughing and breathlessness, which will get worse over the years.

      The definition of chronic bronchitis is chronic cough or mucus reproduction for at least three months in two successive years when other causes have been excluded.

 Emphysema

      Effects the alveoli

      The smokers cough weakens the walls of the alveoli; therefore the lungs cannot take in enough oxygen which leads to breathlessness.

Cancer

      Increased risk of developing lung cancer

      Number of cigarettes smoked per day Annual death rate per 100,000 men

      010-14 (8 times that of non-smokers)

      15-25 (13 times that of non-smokers)

      25 or more25 (25 times that of non-smokers)

Lung Cancer

      Lung cancer kills more people than any other type of cancer and at least 80% of these deaths are caused by smoking. In 1999, 29,406 people in England and Wales died of lung cancer.

      It is the tar in the `cigarettes which contain the carcinogenic “cancer causing” substances

      Not only are you susceptible to lung cancer, but also: mouth, throat, stomach cancer. Cigarette tars contain some of the most carcinogenic chemicals known to man.  Consider this when watching people smoking and exhaling only 10% of the tars they actually take in.  Not only are these chemicals being painted into the lung, but smoker are also constantly painting them up on their lips, tongue, and larynx, swallowing some and thus painting it in the esophagus and throughout the digestive tract.  Smokers have increased incidents of cancer in all of these exposed sites.

Heart Disease

      The role of smoking in Coronary Heart Disease

      Inhaling tobacco smoke causes several immediate responses within the heart and its blood vessels.  Within one minute of starting to smoke, the heart rate begins to rise: it may increase by as much as 30 percent during the first 10 minutes of smoking.

      Nicotine raises blood pressure: blood vessels constrict which forces the heart to work harder to deliver oxygen to the rest of the body.  Meanwhile,

      Carbon monoxide in tobacco smoke exerts a negative effect on the heart by reducing the blood’s ability to carry oxygen.

      Smoking tends to increase blood cholesterol levels. 

      Carbon monoxide attaches itself to haemoglobin (the oxygen-carrying pigment in red blood cells) much more easily than oxygen does.  This reduces the amount of oxygen available to the tissues. This again will put pressure on the heart!

Cilia and smoking

      The following series of slides illustrate microscopic changes that happen when a person smokes.  The first slide is showing an illustrated blow-up of the normal lining of the bronchus. On the top we see the cilia, labeled (H).  They are attached to columnar cells, labelled (I).  The cilia sweep the mucous produced in the goblet cells, labeled (J) as well as mucous coming from deeper glands within the lungs and the particulate matter trapped in the mucous.  The bottom layer of cells, labelled (L) is the basal cells.

      Below we start to see the changes that occur as people begin to smoke.  You will see that the columnar cells are starting to be crowded out and displaced by additional layers of basal cells. 

      Not only are fewer cilia present but the ones that are still functioning are doing so at a much lower level of efficiency.  Many chemicals in tobacco smoke are toxic to cilia, first slowing them down, soon paralyzing them all together and then destroying them.

Healthy Lungs

      You can see how the lung looks without the effects of inhalation of smoke.

               Note black specks throughout indicative of carbon deposits from pollution.

Lung after smoking

Smokers lung with cancer.  White area on top is the cancer, this is what killed the person.  The blackened area is just the deposit of tars that all smokers paint into their lungs with every puff they take