Presentation on theme: "emphysema (chronic obstructive pulmonary disease or COPD)"— Presentation transcript:
1 emphysema (chronic obstructive pulmonary disease or COPD) The Effects of SmokingDescribe the effects of smoking on the mammalian gas exchange system, with reference to the symptoms ofchronic bronchitisemphysema (chronic obstructive pulmonary disease or COPD)lung cancer
2 Constituents of cigarette smoke that cause damage to health Cigarette smoke contains over 4000 different chemicals. The main problems are caused by :Tar, a mixture of substances including carcinogens (chemicals that cause cancer)NicotineCarbon Monoxide
3 Short Term Effects of Tar on Gas Exchange System (NB: tar does not pass through lung tissue into blood stream)CauseDamage to gas exchange systemTar settles on lining of airways and alveoliChemicals in tar causes an allergic reactionTar paralyses or destroys cilia of ciliated epitheliumTar stimulates over-production of mucus from goblet cells and mucus glandsMucus trapped and collects in airwaysMicrobes trapped in airways
4 Short Term Effects of Tar on Gas Exchange System (NB: tar does not pass through lung tissue into blood stream)CauseDamage to gas exchange systemTar settles on lining of airways and alveolitar layer slows gas exchange by increasing diffusion distance for gasesChemicals in tar causes an allergic reactionsmooth muscle in airway walls contracts. Reduces lumen diameter, restricts flow of air in and out of airwaysTar paralyses or destroys cilia of ciliated epitheliumCilia no longer move mucus out of airwaysTar stimulates over-production of mucus from goblet cells and mucus glandsMucus collects in airways, bacteria and viruses become trapped in mucus. Cilia unable to move it.Mucus trapped and collects in airwaysCan cause blockages in small bronchioles preventing air flow in and outMicrobes trapped in airwaysLikely to cause infection in lungs,eg: pneumonia and influenza
5 Long Term Effects of Tar on Gas Exchange System CauseEffect on gas exchange systemIrritation of airways by mucus and microbesFrequent coughing damages cells lining the airways,Frequent coughing thickens the smooth muscle layerConstant infections encourage more white blood cells to pass into lung tissuesDamaged alveoli and bronchioles cannot stretch and recoil properlyDeposition of tar which contains carcinogens on lung tissue
6 Long Term Effects of Tar on Gas Exchange System CauseEffect on gas exchange systemIrritation of airways by mucus and microbesleads to frequent and persistent coughingFrequent coughing damages cells lining the airways,then damaged cells are replaced by thicker less flexible scar tissueFrequent coughing thickens the smooth muscle layerthen the thicker muscle layer reduces the lumen of the airway so air flow in and out is restrictedConstant infections encourage more white blood cells to pass into lung tissueswhite blood cells produce elastase enzyme which breaks down elastic tissue in alveoli and bronchiolesDamaged alveoli and bronchioles cannot stretch and recoil properlyso air is not pushed out of alveoli, alveoli may burst due to coughing, bronchioles may collapseDeposition of tar which contains carcinogens on lung tissuecarcinogens taken into nucleus of cells, causes mutations to DNA. Mutation of genes can cause uncontrolled cell division ie: a tumour
7 Diseases of Gas Exchange system associated with smoking Lung CancerBronchitisEmphysemaCOPD (chronic obstructive pulmonary disease)
8 Lung CancerSEM of a lung cancer cell. Cancer cells divide rapidly in a chaotic, uncontrolled manner. They may clump to form tumours, which invade and destroy surrounding tissues. Lung cancer is a common form of cancer, frequently associated with smoking tobacco. It often develops at the entrance to the bronchi It causes a persistent cough, shortness of breath and chest pain. Blood may be coughed up in sputum. Cancer may spread to other areas of the body. Treatment includes surgical excision of the affected areas of the lung, with radiotherapy and chemotherapy.
9 Lung cancer Outside lung Inside lung Black deposits of tar in tissues Large cancerous tumour
13 Bronchitis Inflammation of the airway lining, damaged cilia, increased mucous production. Persistent cough, mucus filled with microbes and white blood cells
14 Signs and symptoms of Bronchitis CoughProduction of mucus (sputum), either clear or white or yellowish-gray or green in colorShortness of breath, made worse by mild exertionWheezingFatigueSlight fever and chillsChest discomfortFrequent respiratory infections (such as colds or ‘flu) with a worsening productive cough
17 EmphysemaSEM of human lung tissue affected by emphysema. Emphysema is a disease in which the alveoli of the lung become enlarged and the walls separating them are damaged. This damage occurs as a result of elastase enzyme breaking down the elastic fibres which allow the alveoli to expand and recoil. There is difficulty exhaling. Surface area for gaseous exchange is reduced, restricting oxygen uptake. This may cause breathlessness, bluish skin, and heart or respiratory failure. Occurrence of emphysema is strongly associated with smoking. Treatment of emphysema is with drugs and the cessation of smoking.
18 Emphysema signs and symptoms Shortness of breath, shallow breathingWheezing, difficulty breathing outFatigue, extreme tirednessHeart failureCyanosis / blue tinge to skinHigh blood pressure to lungsEnlarged right side of heart
19 Learning Outcome Describe the effects of nicotine and carbon monoxide in tobacco smoke on thecardiovascular systemwith reference to the course of events leading toatherosclerosiscoronary heart diseasestrokes.
20 Match the effect that CO and nicotine have on the body to the damage that they cause Sort the cards into 6 pairs
21 Remember Nicotine and Carbon Monoxide enter the lungs and pass through the lung surface into the bloodEffectsConsequencesNicotine stimulates release of adrenalineAdrenalin:Increases heart rateIncreases breathing rateConstricts arteriolesIncreases blood pressureNicotine causes constriction of the arteriolesReduces blood flow to extremitiesMay lead to necrosis of tissues-lack of O2 and glucoseIn extreme cases may result in amputationNicotine makes platelets more stickyIncreases the risk of blood clot or thrombus formingNicotine mimics action of neurotransmitters at synapsesMakes the smoker feel more alertCarbon monoxide combines with haemoglobin to form carboxyhaemoglobinReduces the oxygen carrying capacity of bloodWhen exercising heart rate and breathing rate rise more than normalCarbon monoxide causes damage to arterial endothelial liningsDamage to lining makes it more likely that plaques develop
22 Development of Atheromas (Atherosclerosis) Damage to the arterial endothelium by CO or hypertensionCholesterol, fatty deposits and cellular waste are deposited under the damaged area in the wall, which is then repairedInflammation at the site stimulates monocytes to infiltrate the areaMonocytes differentiate into macrophages which ingest the cholesterol and turn into “foam cells”. This is what forms the “plaque”These changes also stimulate smooth muscle cells to multiply and form a “cap”The whole area increases in size and extends out into the lumen of the artery restricting blood flow.The atheroma may finally break through the repaired endothelium again and release some of the lumps of fatty deposit into the blood stream. This can increase the likelihood of blockages in small arteries.
23 Development of Atheroma in arterial walls (Atherosclerosis)