Lung Disease

Question 1

Tuberculosis

Answer 1

• tb is a lung disease caused by bacteria
• infected with tb bacteria the immune system cells build a wall around bacteria in the lungs
• forms small hard lumps = tubercules
• infected tissue within tubercules dies and gaseous exchange surface is damaged so tidal volume decreases
• tb causes fibrosis which further decreases tidal volume
• reduced tidal volume means less air inhaled with each breath do in order to take enough oxygen particles breath faster so ventilation increases

Question 2

TB symptoms

Answer 2

• persistent cough
• coughing up blood and mucus
• chest pains
• shortness of breath
• fatigue

Question 3

Fibrosis

Answer 3

• formation of scar tissue in lungs
• result of an infection or exposure to substances like asbestos or dust
• scar tissue is thicker and less elastic than normal lung tissue so it’s less able to expand so cant hold in as much air as normal so tidal volume reduced and so is FVC
• theres a reduction in the rate of gaseous exchange so diffusion is slower across thicker scarred membrane
• faster ventilation rate than normal to get enough air into lungs to oxygenate their blood

Question 4

Fibrosis symptoms

Answer 4

• shortness of breath
• dry cough
• chest pain
• fatigue
• weakness

Question 5

Asthma

Answer 5

• respiratory condition where the airways become inflamed and irritated
• causes vary - allergic reaction
• during asthma attacks the smooth muscle lining on the bronchioles contract and a large amount of mucus is produced
• causes constriction of the airways making it difficult to breathe properly
• air flow in and out severely reduced so less oxygen enters the alveoli an moves into the blood
• reduced air flow means that FEV severely reduced

Question 6

Asthma Symptoms

Answer 6

• wheezing
• tight chest
• shortness of breath
• during attack symptoms come on very suddenly can be relieved by drugs which causes muscle in bronchioles to relax opening up the airways

Question 7

Emphysema

Answer 7

• caused by smoking or long term exposure to air pollution
• foreign particles in smoke become trapped in alveoli
• this causes inflammation which attracts phagocytes to area
• contain enzyme that break down elastin
• loss of elastin means alveoli can’t recoil to expel air as well
• leads to destruction to alveoli walls, reduces SA rate of gaseous exchange decreases

Question 8

emphysema symptoms

Answer 8

• shortness of breath
• wheezing
• increase of ventilation rate to try increase amount ot air reaching lungs

Question 9

Effects on gas exchange

Answer 9

• reduce rate of gas exchange in alveoli so less oxygen means less diffusion
• body cells less oxygen
• rate of aerobic decreases
• less energy released so more tired and weak