Lung Diseases

Question 1

Pulmonary TB

Answer 1

Immune cells build wall around TB bacteria in lungs
Forms tubercles (small hard lumps)
Infected tissue within tubercles dies, damage to gas exchange surface
Decreases tidal volume
Causes fibrosis
Faster ventilation rate needed

Question 2

Fibrosis

Answer 2

Formation of scar tissue in lungs
Scar tissue thicker and less elastic
Lungs less able to expand so tidal volume and FVC reduced
Reduction in rate of gaseous exchange (diffusion across thicker membrane)
Faster ventilation rate needed

Question 3

Asthma

Answer 3

Airways inflamed and irritated
Allergies (pollen, dust)
Smooth muscle lining the bronchioles contracts and a large amount of mucus is produced
Causes constriction of the airways- reduced air flow, reduced FEV

Question 4

Emphysema

Answer 4

Smoking, air pollution
Inflammation, attracts phagocytes which produce enzyme that breaks down elastin (protein in walls of alveoli that provides the elasticity)
Loss of elastin- alveoli can’t recoil. Air remains trapped in alveoli
Destruction of alveoli walls reduces surface area
Increased ventilation rate needed

Question 5

Summary

Answer 5

All these diseases reduce the rate of gas exchange