Lecture 3

Question 1

What is hysteresis

Answer 1

Loss of energy

Question 2

How is something stretched or distorted

Answer 2

When it is subjected to a force

Question 3

What causes recoil pressure

Answer 3

Elastic recoil and its elastance

Question 4

On inhalation what happens to intrapleural pressure

Answer 4

Lowers the pressure

Question 5

Is intrapleural pressure positive or negative compared to ATM and alveoli

Answer 5

Negative

Question 6

What happens in pneumothorax

Answer 6

There is a hole between the ATM or alveoli and intrapleural space, te pressure surrounding the lung will rise causing it to collapse

Question 7

What is static lung compliance

Answer 7

Measurement of how easy the lungs can be stretched at rest

Question 8

What is dynamic lung compliance

Answer 8

Measurement of stretchiness during breathing

Question 9

What happens in lung fibrosis

Answer 9

Stiffened by laying down of collagen and fibrin. Compliance is reduced

Question 10

What happens in emphysema

Answer 10

Parenchyma of lung is destroyed. Less elastic recoil and compliance is increased

Question 11

Why is it that children’s lungs get problems

Answer 11

Deficiency of surfactant

Question 12

What is an endochondral tube

Answer 12

Tube used for mechanical ventilation

Question 13

What effect does artificial surfactant have

Answer 13

Reduces surface tension in alveoli stabilising them and increasing lung compliance

Question 14

If a lung is filled with water how much easier is it to inflate

Answer 14

2x as easy

Question 15

How does a skin of a liquid exist

Answer 15

Due to an imbalance of forces on the surface molecules

Question 16

What does the skin of liquid seek

Answer 16

Entropy

Question 17

If alveoli were only line with interstitial fluid pressure would have to be

Answer 17

3kPa

Question 18

Surfactant can be obtained by

Answer 18

Bronchial lavage

Question 19

Is surface tension and elastic recoil is reduced does it make it harder to breathe

Answer 19

Makes breathing easier

Question 20

How is surfactant made up

Answer 20

Phosphatidylcholine

Choline head
Phosphate neck
Triglyceride shoulders
Polyunsaturated fatty acid chains

Question 21

Compliance rule

Answer 21

Change in volume
___________________
Change in pressure

Question 22

What is the lung compliance of a normal male

Answer 22

2L/kPa

Question 23

Because lung compliance varies in sex and size how do we measure it

Answer 23

Specific lung compliance

Question 24

How don’t the lungs fully empty on expiration

Answer 24

As the thorax is flighty pulled out as the thoracic cage holds the

Question 25

Total compliance rule

Answer 25

Total compliance =

Lung compliance + wall compliance

Question 26

Name 5 factors affecting lung compliance

Answer 26

1. Lung size
2. Recent pattern of breathing
3. Age
4. Posture
5. Disease

Question 27

What is compliance

Answer 27

Ability of the lungs to stretch in volume when pressure is applied