Title: Smoking, nicotine and tar 5 th February 2015 Learning question: Why is smoking so bad for you?

Aims from specification document (p) describe the effects of smoking on the mammalian gas exchange system, with reference to the symptoms of chronic bronchitis, emphysema (chronic obstructive pulmonary disease) and lung cancer; (q) describe the effects of nicotine and carbon monoxide in tobacco smoke on the cardiovascular system with reference to the course of events that lead to atherosclerosis, coronary heart disease and stroke; (r) evaluate the epidemiological and experimental evidence linking cigarette smoking to disease and early death (HSW3, 6a, 7a, 7b, 7c).

Questions, questions, questions! 1) What does Carbon Monoxide do to the body? 2) What does Nicotine do? 3) What is a carcinogen and where are they found? 4) What happens if the heart, muscles and cells don’t get enough oxygen?

Smoking is cool ?

This is the amount of tar that would collect in a smokers lungs after a year if they smoked cigarettes per day

Tar – short term effects Tar settles in the lining of the airways and alveoli – Increasing diffusion distance for oxygen to travel Can stimulate allergic reactions – smooth muscle that lines the airways can contract, restricting blood flow (lumen diameter decrease) Mucosal build up – cilia destroyed Goblet cells enlarge – over stimulation of mucus that collects in airways Cilia damage>mucus build up> bacteria trapped> blockage of bronchioles > increased susceptibility to infection and disease

Tar –Long-term effects “smokers cough” – attempt to rid respiratory tract of dirt, dust, bacteria and mucus Persistent cough results in alveolar damage – Scar tissue replaces smooth muscle – Thinker and less elastic – Decreases lumen diameter therefore less air flow

Tar –Long-term effects Frequent infections result in inflammation of the lining of the airways, especially the epithelium WBCs respond to infection, leave blood and get to airways. WBCs produce enzymes that partly digest lung lining in order to get into air spaces Elastase production damages lung lining and ability of alveoli to recoil and push out air

Action of elastase on alveoli

Mini Plenary Tar destroys goblet cells TRUE FALSE

In the long term, smoking will reduce air flow to lungs TRUE FALSE

Mucus production decreases with smoking TRUE FALSE

White blood cells release enzymes that destroy the lining of the lungs TRUE FALSE

Lung cancer Write a summary to describe how cancer can result from smoking. Make sure that you use and understand the following key words: – Carcinogen – Mutation – Genes – bronchi

Chronic bronchitis Inflammation of lining of airways Results in cilia damage and over production of mucus that collects in lungs Leads to lung infections when bacteria are trapped in mucus

What is emphysema? This is destruction of lung tissue, most often from smoking. It can cause symptoms of cough, wheezing, and shortness of breath. It is diagnosed by imaging and lung function tests.

Chronic Obstructive Pulmonary Disease (COPD) Combination disease of asthma, chronic bronchitis and emphysema Largely mis-diagnosed as asthma in patients and incorrect medication administere Stop smoking!

Lung cancer Continual coughing, shortness of breath, chest pain and blood in sputum are classic signs of lung cancer

Nicotine Nicotine is a highly addictive chemical found in cigarettes that makes it difficult to give up. Body becomes chemically dependant on nicotine Mimics neurotransmitters and makes NS more alert and user feels more sensitive Stimulates release of adrenaline – increase HR, BR and vasoconstriction of arterioles, therefore increases BP too

Nicotine Vasoconstriction of arterioles reduces O 2 delivery to extremities – effects?? Can develop necrotic tissue -> amputations Affects platelet morphology – makes them sticky – Risk of blood clot or thrombus

Carbon Monoxide Can reduce the concentration of oxygen in the bloodstream. It does this by combining with a pigment in red blood cells called haemoglobin. Haemoglobin normally helps to carry oxygen, but when CO is present it carries that instead.

Problems caused by changes to the blood system Chronic Heart Disease (CHD) is multifactorial No single cause, many risk factors Atherosclerosis Thrombosis CHD Stroke

Atherosclerosis As we age, our arteries harden due to many factors – Smoking increases the risk Body naturally repairs this by action of phagocytic cells Smooth muscle cells are encouraged to grow, as is fatty deposits that include cholesterol from LDLs Deposits, called artheromas, are a mix of cholesterol, fibres, dead blood cells and platelets Deposition in the lining of the arteries is called atherosclerosis

Atherosclerosis Atheromas build up under endothelium in the artery wall Can grow so big, they break through the inner lining of the artery Plaques develop in the lumen, leaving rougher surface and smaller diameter for blood flow

Thrombosis Blood flowing past a plaque increases risk of a clot Sticky platelets (nicotine) increase the risk of clots The atheroma sticking out has a delicate membrane that is easily ruptured by blood cells trying to get through the narrow lumen The fatty deposits underneath are exposed, causing blood cells to stick Thrombus, or blood clot and stick in an artery, or break free until it get trapped in a narrower artery

CHD Heart itself is “fed” oxygen and glucose by the coronary arteries Carry blood at high pressure, so prone to atherosclerosis Plaques here can lead to CHD in three forms: – Angina – Myocardial infarction – Heart failure Use page 181 of your textbook to describe these forms of CHD

Stroke A stroke is death in part of the brain tissue as a result of loss of blood flow Causes: – Thrombus floating around in artery that leads to the brain – Artery leading to brain bursts (haemorrhage)