COPD

Question 1

What are the risk factors for COPD?

Answer 1

• smoking tobacco
• genetics
• inhalation of irritants
• frequent childhood respiratory infections
• advanced age

Question 2

How does smoking cause the destruction of elastic fibres in the lung?

Answer 2

• smoking causes inflammation
• neutrophils release elastase
• smoking inhibits alpha1antitryptase activity
• elastase (which isn’t being inhibited) destructs elastic fibres

Question 3

Why does wheezing occur with intrathoracic airway obstruction?

Answer 3

• intrathoracic pressure increases when the diaphragm pushes up on the lungs
• the pressure acting on the airways causes them to get narrower
• air whistles as it passes through narrow airways

Question 4

How is ventilation affected by the loss of elastin fibres in alveoli and bronchiole walls of an emphysema pt?

Answer 4

Elastin breaks down in the alveoli → surface area decreases → less gas exchange
Less pull from the alveoli → airways won’t stay open → air gets trapped