Pathophysiology of COPD Flashcards

1
Q

What is COPD a term for?

A

→ a mixture of chronic bronchitis and emphysema

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2
Q

How does lung function decline in healthy people vs people who smoke?

A

→ Lung function naturally declines with age

→ Lung function decline is accelerated in people who smoke

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3
Q

What can the harmful constituents of tobacco smoke cause?

A

→ Acute damage to respiratory tissue generating an inflammatory response

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4
Q

What happens with repeated exposure to tobacco smoke?

A

→ Inflammation becomes pathological

→ Creates chronic and irreversible dysfunction

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5
Q

What are the steps that cause inflammation in COPD?

A

→ Inhalation of reactive oxygen species and noxious chemicals
→ This causes tissue damage
→ The body responds by initiating an inflammatory response
→ Macrophages and neutrophils are activated
→ They secrete proteases to repair damaged tissue
→ Before damage can be repaired more inflammation occurs by smoking again
→ Increased protease burden which damages healthy tissues

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6
Q

What are the long term effects of inflammation?

A

→ Impaired mucociliary clearance
→ More vulnerable to respiratory infection
→ Generates more inflammation
→ Tissue remodelling

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7
Q

What is the layer of mucus in the airways for?

A

→ Trapping small particulates/ bacteria or viruses and moving them up the airways to remove them

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8
Q

What happens to the mucus with COPD?

A

→ Hypersecretion of mucus because toxic particles stimulate the production of it
→ They damage the way cilia work so they cannot beat as effectively
→ Mucus is not cleared well and bacteria live in the mucus and can infect lungs

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9
Q

What pathological features are present in the airways of someone with COPD?

A

→ Excess amounts of mucus within the airways
→ Weakened airway structure
→ Impairment of mucociliary clearance
→ Irritation of sensory neurons (coughing)
→ Decreased luminal area

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10
Q

What happens to alveoli in emphysema?

A

→ Decrease in surface area

→ Loss of elastin fibers means increased compliance and decrease in recoil

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11
Q

Why is not as much gas exchanged in emphysema?

A

→ Higher surface area to volume ratio

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12
Q

What consequence does emphysema have on breathing in and out?

A

→ Easier to expand the lungs (breathing in)
→ Harder to expel the air
→ Alveoli do not recoil so accessory muscles have to be used

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13
Q

What happens as a result of elastin degradation in COPD?

A

→ Loss of patency

→ Loss of elastic recoil

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14
Q

How can COPD lead to heart failure?

A
→ Chronic alveolar hypoxia 
→ Hypoxic vasoconstriction 
→ Pulmonary hypertension 
→Right ventricular hypertrophy 
→ Heart failure
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15
Q

What are 3 conditions that can occur with COPD?

A

→ Hypoxaemia
→Hypercapnia
→ Acidaemia

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16
Q

What is the most effective method of slowing the decline of lung function?

A

→ Smoking cessation

17
Q

What happens to lung function if you quit smoking?

A

→ Doesn’t regenerate but slows the decline

18
Q

How can pathophysiology of COPD be modelled in animals?

A

→ Expose mice to tobacco smoke
→ Measure lung function, airway resistance and compliance
→ Cull animals and take lung samples
→ Measure cytokine and leukocyte levels