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Flashcards in 4 - Disorder of Ventilation Deck (30)
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1
Q

What is the relationship between compliance and elasticity of the lungs?

A
  • One up, other down
  • Compliance to do with expansion and elasticity with rest
2
Q

How does lung elastic recoil affect functional residual capacity?

A
3
Q

How do bronchioles stay open if they have no cartilage?

A

Radial traction - surrounding alveoli pull outward and prevent bronchiole collapse on experiation

4
Q

What is interstitial lung disease?

A
  • Deposition of fibrous tissue in the interstitium, so it gets thicker.
  • Group of diseases with a variety of causes but similar clinical features.
  • Usually caught too late and irreversible
5
Q

What effects does intersitial lung disease have on the lungs and why?

A

- Lower lung compliance due to stiff lungs as collagen fibres less stretchy than elastin

- Elastic recoil increased so lungs are smaller than normal

- Chest expansion reduced

- Inspiratory capacity and vital capacity is reduced

- Less O2 diffusion and more CO2 absorption due to thickening of alveolar walls

6
Q

What are some signs and symptoms of interstitial lung disease?

A

Symptoms: shortness of breath, reduced exercise tolerance, dry cough

Signs: tachypneoa, tachycardia, reduced bilateral chest movement, coarse crackles

Restrictive type of ventilatory defect on spirometry

7
Q

What are some examples of causes of interstitial lung disease?

A

Can all lead to diffuse lung fibrosis

8
Q

How can you treat someone with pulmonary fibrosis?

A
  • Supervised structured exercise therapy
  • May increase lung compliance by stretching, strengthen accessory muscles and teach people to tolerate dyspnoea
9
Q

What effect does respiratory distress syndrome have on lung compliance and elasticity?

A
  • Reduces compliance as lack of surfactant so high surface tension
  • Collapsed alveoli
  • Increase effort to breath so impaired ventilation
10
Q

What happens to the diameter of the bronchioles in pulmonary fibrosis?

A

Not narrowed due to outward pull of fibrous tissue keeping bronchioles open

11
Q

What is emphysema and what effect does it have on the compliance and elasticity of the lungs?

A

- Increased lung compliance as lungs easier to expand due to less elastin

- Elastic recoil decreased

- Narrowing of airways that is irreversible due to loss of elastic fibres exerting radial traction

- Lungs hyperinflated at rest as loss of elastic recoil (barrel chest)

- Obstructive ventilatory defect on spirometry

12
Q

What are some symptoms and signs of emphysema?

A
  • Barrel chest due to hyper inflated lungs
  • Shortness of breath
  • Reduced exercise tolerance
13
Q

What is the main difference between emphysema due to smoking and emphysema due to A1 anti-trypsin deficiency.

A

Genetic defect presents at earlier age

14
Q

Both asthma and emphysema are an example of airway obstructions, what is the main difference between the two?

A
  • Asthma is reversible but emphysema isn’t
  • Pulmonary fibrosis and RDS are ventilatory obstructions
15
Q

What is the mechanism of airway obstruction in asthma?

A
  • Asthma is a chronic inflammatory process which can be triggered by allergic/non-allergic stimuli.
  • Inflammation causes the things in red
16
Q

What is the mechanism of airway obstruction in the three most common obstructive lung diseases?

A
17
Q

Why does a pneumothorax lead to lung collapse?

A
  • Presence of air in pleural space
  • Air flows in from atmosphere

- Elastic recoil of lung causes it to collapse towards hilum as negative pleural pressure and outward recoil of chest can no longer counteract it

18
Q

What are the two types of atelectasis?

A

Incomplete expansion of the lungs (neonatal) or collapse of previously inflate lung so areas of airless pulmonary parenchyma

Compression: when significant volumes of air or fluid, e.g pneumo/haemothorax, accumulate in pleural cavity

Resorption (Lung collapse) complete obstruction of an airway. air is resorbed from the alveoli and collapse, cause could be bronchial carcinoma

19
Q

What causes hypoventilation?

A

When there is an inability to expand the chest, e.g DMD. Any respiratory muscle weakness or severe throacic wall deformity.

Stiff lungs or a severe airway obstruction can also cause poor ventilation

20
Q

What determines the elastic recoil of the lungs?

A
  • The elastin and collagen fibres in the alveolar walls
  • Surface tension of the fluid linin alveoli
21
Q

Why does chronic bronchitis lead to airway obstruction?

A
  • Mucus hypersecretion so increased resistance due to narrowed lumen
  • Reduced cilia so mucus is not cleared effectivley
22
Q

What is the telltale sign of hyperinflation of the lungs?

A

Flattened diaphragm on lateral chest x-ray. Shows a barrelled chest

23
Q

Compare and contrast diffuse lung fibrosis and emphysema.

A
24
Q

How would you treat a pneumothorax?

A
25
Q

What is the steps of the cough reflex?

A
  • Coordinated by cough center in the medulla oblongata
  • Initiated by irritation of mechano and chemoreceptors in respiratory epithelium
  • Use the word glottis not just vocal cords
26
Q

Why is there intercostal recession in a baby with RDS and what would a compliance curve look like in this baby?

A
  • Baby has stiff lungs due to less surfactant so force from inward elastic recoil greater than from the outward force of the chest wall
27
Q

In emphysema what happens to the elastic recoil and compliance of the chest wall and the lung?

A
  • Compliance increases as stretched but reduced chest expansion

- Barrel Chest: transverse diameter becomes equal to anteroposterior diameter

28
Q

Draw a compliance curve for a patient with COPD.

A
29
Q

In forced expiration, what causes the diaphragm to move up into the thorax?

A
  • Anterior abdominal wall muscles
30
Q

What will happen to the size of the lungs if you remove them from the body?

A

Will collapse due to elastic recoil