Week 3 Lung Volumes and Capacities ✅

Question 1

Define hypercapnia

Answer 1

Too much CO2 in blood

Question 2

How does hypercapnia/hypoxaemia affect respiration in COPD?

Answer 2

Reduced ventilation = mucus production, swelling, air trapping and airway collapse

Reduced surface area = break down of alveolar walls and air trapping

Reduced perfusion

Question 3

How does a PE affect respiration?

Answer 3

Ventilation reduced due to pain
Reduced blood flow to area or lung with blockage

Question 4

How do you diagnose a PE?

Answer 4

CT pulmonary angiogram or ventilation perfusion scan

Question 5

How does pneumothorax affect respiration?

Answer 5

Reduced ventilation due to pain and collapsed lung

Reduced surface area due to collapsed lung

Reduced perfusion due to reduced blood flow and reduced cardiac output

Question 6

What effect does reduction in muscle mass and power have on respiration?

Answer 6

Loss of muscle results in reduced effectiveness of cough reflex

Loss of muscle power results in reduced FVC and FEV1

Question 7

What effect does changes in pulmonary compliance have on respiratory system?

Answer 7

Lung tissue complained increases with breakdown of elastin
Chest wall complaisance decreases due to stiffening of intercostal muscles and kyphosis

Question 8

What effect does reduction in diffusion capacity have on respiration?

Answer 8

Alveolar surface area decreases with age due to gradual breakdown of alveoli
Alveolar walls thicken which increases diffusion distance
Surface area of small airways reduced due to collapse from loss of elasticity

Question 9

What effect does decline in control of breathing have on respiration?

Answer 9

Reduction in sensitivity of peripheral and central chemoreceptor functions

Question 10

What does Virchow’s Triad mean?

Answer 10

3 factors contributing to thrombus formation

Question 11

What are the 3 components of Virchow’s triad?

Answer 11

Stasis of venous blood
Vascular injury
Alterations in coagulation (hypercoaguability)

Question 12

How does residual volume change in obstructive disorders?

Answer 12

Increases due to trapping of air and hyperinflation e.g. COPD

Question 13

How does inspiratory reserve volume change in restrictive disorders?

Answer 13

Decreases due to lost elasticity and stiffness e.g. cystic fibrosis or kyphosis

Question 14

What can you do if patients cannot do FEV1?

Answer 14

FEV6

Question 15

What is the difference between a restrictive and an obstructive lung condition?

Answer 15

Restrictive restricts lung EXPANSION

Obstruction - airways narrowed