Part 2

Infectious Diseases caused by Pathogens: Tuberculosis (bacteria) Cholera (bacteria) Malaria (protista) HIV (virus) COMMUNICABLE!!!! NON-COMMUNICABLE!!!! Non- Infectious Diseases : Cardiovascular disease Lung Disease (COPD, bronchitis, emphysema) Cancer

Sign vs. Symptom Sign Visible expression of a disease Doctor can see these through examination or testing Ex. High temperature Rash Symptom Cannot be detected by examination Things a patient feels but a doctor cannot detect Must be reported by patient Ex. Headache Dizziness

Smoking and Lung Disease Smoke contains substances that effect Gas Exchange System and Cardiovascular System Small particles less than 2 um can reach the alveoli Filter system of respiratory system is much slower in bronchioles  particles settle in alveoli  settling of particles leads to influenza, pneumonia, allergies, asthma Mainstream vs. side stream smoke MS  from filter end SS  more toxic to resp. system

TarNicotine Carbon Monoxide Mixture of many chemical substances Carcinogens Additive Absorbed readily by blood and travels quickly to brain Effects Nervous System binds to receptors on neurons in brain Increase release of DOPAMINE (pleasure neurotransmitter=addiction) Effects Circulatory System Increases release of ADRENALINE in blood  stimulate DECREASE in diameter of arteries (VASOCONSTRICTION)= increase in HR, BP, and BR = decrease in blood supply to extremities Increase likelihood of blood clots forming Combine irreversibly with haemoglobin (carboxyhaemoglob in) = decrease amount of haemoglobin available for oxygen to attach to = decrease in oxygen available to tissues Damages lining of arteries

Effects of Smoking Gas Exchange System Chronic Obstructive Pulmonary Disease (COPD) Chronic Bronchitis Emphysema Lung Cancer Cardiovascular System Atherosclerosis Coronary Heart Disease (CHD)

Carcinogens in Tobacco Nicotine Tar carbon monoxide Ammonia Formaldehyde Phenols Creosote Anthracene Pyrene hydrocyanic acid Arsenic lead

Tar particulate matter derived from burning organic compounds

Chronic Obstructive Pulmonary Disease COPD Chronic bronchitis and emphysema Extremely disabling Causes: Pollution (indoor/outdo or) Smoking (chemicals is smoke)

Narrowing of Air Passageways Bad! 2 main causes: 1. Inflammation Immune response (inflammatory response) Due to infection in respiratory tissue (from bacteria/particles/pathogens in slow moving mucus) 2. Build up of scar tissue and smooth muscle mucus sitting in passageways not being moved  causes constant cough  causes damage to epithelium  need for more smooth muscle and build up of scar tissue = narrowed lumen

Chronic Bronchitis Increased mucus secretion Goblet cells Enlarged mucus glands Ciliated epithelium weakened or destroyed Ciliated epithelial cells beat LESS efficiently (cannot effectively move mucus out) Mucus contains dust particles; become infected with bacteria/viruses Stimulates cough = damage to airway tissue = airway stiffens and narrows Build up of mucus  blocks alveoli  difficulty in gas exchange (diffusion distance b/t air in alveoli and blood in capillaries is greater)

Emphysema Smoking causes Inflammation of lungs Infection in lungs = inflammation = narrow airways Increase in WBC (phagocytes) in lung tissue WBC leave blood and line airways Secret enzyme ELASTASE to they can break up elastic (elastin) fibers surrounding alveoli and reach surface of alveoli to destroy bacteria No more elastin = no stretching/relaxing of alveoli when breathing Bronchioles collapse during exhalation Trap air in alveoli  burst; larger air spaces Decrease SA for gas exchange Decrease # of capillaries Blood vessels in lungs become resistant to blood flow  pressure in pulmonary artery INCREASES to compensate for this  increase in size of RIGHT side of heart Decrease oxygen absorbed in blood Symptoms  shortness of breath, wheezing 60 million people world wide effected

Asthma

Lung Cancer Caused by carcinogens in TAR Cause mutations to DNA Effects genes that control cell division Especially with epithelial cells of respiratory tissue DNA damage  tumor formation Forms in lungs AND other parts of gas exchange system Spreads from bronchial epithelium  lymphatic tissue  metastasis  Secondary tumors form elsewhere (malignant) Symptoms: chest pain, fatigue and weight loss

Lung Cancer Methods to locate Bronchoscopy Chest x-ray CT scan Treatment Surgery Radiotherapy chemotherapy

Cholesterol Important in: --cell membranes --Vitamin D synthesis in skin -Hormone synthesis in ovaries, testes, adrenal gland LDL HDL Low Density Lipoprotein Transport cholesterol from liver to tissues and artery walls Deposits cholesterol at damaged site High Density Lipoprotein Removes cholesterol from tissues Transports cholesterol to liver to be excreted Protection against atherosclerosis

Atherosclerosis Definition: thickening and loss of elasticity in walls of arteries Caused by build up of plaque in blood vessel walls Plaque: rough patch of cholesterol rich atheroma on artery walls Reduces elasticity AND restricts blood flow Atheroma: fatty material containing Platelets, Dead muscle cells, Cholesterol, Fibers Atheromatous streaks Yellow streaks in artery caused by tobacco smoke or High BP Phagocytes rush to damaged area  secrete proteins to stimulate growth of smooth muscle cells to repair damage Cholesterol accumulate in area

Atherosclerosis Effects of Plaque on artery wall Growth pushes inwards towards lumen, reducing blood flow Ruptures through lining of artery creating rough surface lining artery that stimulates formation of clots  forms THROMBUS (clot ) THROMBOSIS  formation of thrombus that interrupts blood flow Tissues starved of oxygen and nutrients Especially dangerous in coronary artery  heart attack Especially dangerous in brain  stroke Nicotine and CO increase risk of developing atherosclerosis

Stroke 2 major causes 1. Artery in brain bursts and blood leaks into brain tissue (brain hemorrhage) 2. Blockage in brain artery due to atherosclerosis or thrombosis Cerebral Infraction When brain tissue is starved of oxygen and dies Different degrees of severity Different areas effected

Coronary Heart Disease CHD Definition: atherosclerosis in coronary artery that supplies heart muscle with oxygenated blood Arteries narrow, heart has to beat harder to get blood to itself  increase in blood pressure Harder for heart to get oxygen and nutrients it needs, esp. during exercise Three types 1. Angina pectoris Symptom: severe chest pain during exertion Caused by severe shortage of blood to heart muscle No death of heart tissue 2. Heart Attack (myocardial infraction) When large branch of CA is obstructed by clot Part of heart muscle starved of oxygen and dies Symptoms: sudden and severe chest pain Fatal unless treated immediately 3. Heart Failure Caused by blockage to major coronary artery Gradual damage to heart muscle Heart weakens and fails to pump effectively

Evidence for Effects of Smoking on Health Epidemiological Evidence Consists of data collected about people’s smoking habits and their health Large #s of people should be involved Look for correlations b/t smoking and particular disease Shows that there COULD be a causal relationship between smoking and a disease (not definite)…ASSOCIATION Must gather physiological evidence to state definite relationship Experimental Evidence Consists of carrying out experiments IV: whether person smokes of not (or how much they smoke) DV: aspect of physiology All other variables kept constant Unethical in humans 1960s  experiments with dogs and other animals Conclusion: smoking increases risk of developing cancer More ethical experiments now Carried out with lungs tissue cells grown in culture exposed to various cigarette chemicals

Preventing and Treating CHDs Prevention Lifestyle choices that reduce risk factors Screening Factors that Increase Risk of CHD Inheriting particular alleles of genes Eating a diet high in saturated fats and cholesterol No exercise Obesity smoking

Treating CHD Medication Lower BP Decrease clotting Prevent abnormal heart rhythms Reduce retention of fluid in blood Decrease cholestreol concentration in blood Coronary bypass Piece of blood vessel is taken from another part of body and sewn in place as alternate route for oxygen to flow from aorta to heart muscle Heart transplant Must be heart from person who has just dies Similar tissue type Patient needs to take immunosuppressant drugs for rest of life to prevent rejection

Know sequential events and link to BIG picture! Damage to endothelial lining caused by changing/high blood pressure (nicotine) and by damaging chemical components (smoking) cause plaque formation Exposure of fibrous and smooth muscle tissue leading to increase in tissue (may protrude into lumen) Platelet damage and clot formation (nicotine effect plus non-smooth lining causing turbulent blood flow)—thrombosis Cholesterol deposition and macrophage attraction to damaged area- atheroma/atheromatous streaking Overtime, calcium deposition (causes hardening and loss of elasticity)— atherosclerosis (arteriosclerosis) Above effects causing narrowing in lumen of coronary artery, reducing blood flow to cardiac muscle = insufficient oxygen and glucose(angia, heart attack) Above effects in coronary artery = Coronary Heart Disease (CHD) Above effects in arteries serving brain that lead to reduced blood supply (thrombosis or aneurysm) = strokes