Week 1 .3

Question 1

What is Emphysema?

Answer 1

Alevoli is destructed, so less SA and less gas exchange.

Inhalation is ok as air can get in, but exhalation is impaired due to loss of elastic fibres. Internal intercostal and abdominal muscles are required to squeeze air out. This is exhausting

Po2 in blood is low

Question 2

What is fibrosis?

Answer 2

Fibrous tissue develops in lung alveolar space, making inhalation difficult

Tissue may develop between alveoli and capillaries, increasing distance and thickness, decreasing diffusion

Lung compliance is decreased as lung resists stretch. Means less volume increase and big change in pleural pressure

Question 3

What is pulmonary oedema?

Answer 3

Fluid in space between alveoli (INTERSTITUM), usually due to high blood pressure pushing plasma fluid into interstitial space, increasing diffusion distance

CO2 is soluble in water so pCO2 is normal

O2 is not very soluble in water so pO2 is very low in capillaries

Question 4

What is asthma?

Answer 4

Affects ventilation due to bronchial constriction - not diffusion. Leads to low pO2 overall as less O2 is present in alveoli

Question 5

Obstructive vs Restrictive lung disease?

Answer 5

Obstructive - obstruction of airflow

Restrictive - restriction of lung expansion

Question 6

What impairments does obstructive lung disease cause and give examples (3)

Answer 6

Affects exhalation. Asthma, COPD including Emphysema and Coronary bronchitis

Question 7

What impairments does restrictive lung disease cause and give examples (3)

Answer 7

Affects inhalation as lungs ability to expand is impaired. This decreases lung compliance. Fibrosis, Oedema and IRDS are examples

Question 8

What is spirometer and what does it measure?

Answer 8

Lung function test. Can be measures statically - amount of air disregarding time - or dynamically - time taken for set amount of air to be exhaled

Question 9

What cant spirometry be used for?

Answer 9

Measuring residual volume or total lung capacity. This is because residual volume is never exhaled - always in lungs so cant be measures extenally

Question 10

What does the FEV1/FVC ratio measure and tell us?

Answer 10

Amount of air exhaled in 1 second/ total air exhaled. Lung test

Question 11

What is the average FEV1 and FVC of a man?

Answer 11

4L FEV1 and 5L FVC so 80% FEV1/FVC

Question 12

What varies and what is consistent in a healthy human regarding FEV1/FVC?

Answer 12

With age, height and health, the values differ. However the ratio is always constant around 80% when in health

Question 13

Which lung disease type causes a great impact on the FEV1/FVC ratio?

Answer 13

Obstructive restricts exhalation, so FEV1 is significantly decreased, and FVC is decreased a bit. Leads to a low ratio

Question 14

What is a limitation of the FEV1/FVC test?

Answer 14

Restrictive diseases usually have normal or above normal ratio, because exhalation is not impaired. This means the FEV1/FVC test may not always be indicative of health

Question 15

What does FEV1 and FVC stand for?

Answer 15

FEV1 is forced expiratory volume in 1 second

FVC is forced vital capacity

Question 16

How much intrapleural pressure change in inspiration and expiration?

Answer 16

Decreases in inspiration to expand lungs like balloon. Increases in expiration to push air out

Question 17

Why is pleural pressure needed for high compliance? (3)

Answer 17

1. Overcome lung inertia during inspiration
2. Overcome surface tension in alveoli during inspiration
3. Push air out along with volume decrease of lungs during expiration

Question 18

What happens to compliance during an obstructive disease?

Answer 18

Compliance is the same or even increased. Inhalation isn’t impaired, but patient doing more work to expire, so pleural pressure becomes positive which should not happen

Question 19

What happens to compliance during a restrictive disease?

Answer 19

It’s much lower because inspiration is impaired, so it takes a far higher change in intra-pleural pressure to expand lungs to the same volume