36. Respiratory biophysics & physical examination

Question 1

What is Henry’s law?

Answer 1

At constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is proportional to the partial pressure of that gas

Question 2

What is the capillary phenomenon?

Answer 2

capillary pressure difference sustained across the interface between 2 static liquids due to surface tension

Question 3

Henry’s law equation

Answer 3

p = k * c

Question 4

Capillary phenomenon equation

Answer 4

dp = 2gamma / R
p : pressure
gamma : surface tension
R : radius of curvature

Question 5

What doe surface tension result from?

Answer 5

surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion), causing an inward force at the surface (like an elastic mb)

Question 6

What is intrapulmonary pressure

Answer 6

Pressure exerted by gases within the alveoli

Question 7

How does intrapulmonary pressure change in the respiratory cycle?

Answer 7

it decreases as lung volume increases (inspiration)

Question 8

How does intrathoracic pressure change in the respiratory cycle?

Answer 8

It becomes more negative as the chest wall expands during inspiration

Question 9

What is the transmural / transpulmonary pressure?

Answer 9

Pressure difference across the chest wall

Question 10

How many dichotomic division are there

Answer 10

23-25

Question 11

How many alveoli are there?

Answer 11

About 300 million

Question 12

Total alveolar area

Answer 12

About 100m²

Question 13

3 membranes separating the gas exchange surfaces

Answer 13

1. Alveolar epithelium
2. basal membrane
3. Endothelial membrane

Question 14

What are the 4 lung volumes?

Answer 14

1. Tidal volume
2. Expiratory reserve volume
3. Inspiratory reserve volume
4. Residual volume

Question 15

What are the 4 lung capacities?

Answer 15

1. Vital lung capacity
2. Inspiratory capacity
3. Functional residual capacity
4. Total lung capacity

Question 16

What is functional residual capacity?

Answer 16

Volume of air in the lung after passive expiration

Question 17

What are the major mechanisms that drive pulmonary ventilation? (3)

Answer 17

1. Atmospheric pressure
2. Alveolar pressure
3. Intra-pleural pressure

Question 18

What is eupnoe?

Answer 18

Normal breathing (14-16 /min)

Question 19

What is polypnoe / tachypnoe?

Answer 19

Number of breaths over 16/min

Question 20

What is dyspnoe?

Answer 20

Shortness of breath

Question 21

Compliance formula

Answer 21

C = V / P

Question 22

What is surfactant

Answer 22

protein produced by alveolar cells, reduces surface tension and thus reduces the pressure needed to keep the alveoli open

Question 23

Usual transmural pressure

Answer 23

0.7 kPa

Question 24

Usual respiratory volume

Answer 24

0.5 L

Question 25

Average work of the lungs (formula and value)

Answer 25

W = Ptm * V | 0.35 J / inspiration (294J/h)

Question 26

What is inspection?

Answer 26

Visual examination of the patient

Question 27

What do you analyze with inspection?

Answer 27

Behavior, morphology, structure, color

Question 28

What is the cause of ictarus, jaundice?

Answer 28

Hyperbilirubinemia

Question 29

What is palpation?

Answer 29

Examining the patient by touching

Question 30

What do we analyze with palpation?

Answer 30

shape, location, firmness, elasticity, viscosity...

Question 31

What is distensibility?

Answer 31

Ability to be able to stretch and expand under pressure

Question 32

What is viscous matter?

Answer 32

Matter that resists shear flow and strain linearly with time when a stress is applied

Question 33

When does extension of the spring stop?

Answer 33

When the elastic spring force equals that of the external force

Question 34

What do we examine with percussion

Answer 34

Content, shape, boundaries

Question 35

What are the types of percussion sounds?

Answer 35

Flat, dull and resonating

Question 36

What is auscultation?

Answer 36

Examining the patient by listening to sound

Question 37

What is the 1st Korotkow's sound?

Answer 37

Sharp thuds, starts at systolic pressure

Question 38

What is the 2nd Korotkow's sound?

Answer 38

Blowing sound, almost silent

Question 39

What is the 3rd K sound?

Answer 39

crisp thud, quieter than phase 1

Question 40

What is the 4th sound?

Answer 40

Muffled sound

Question 41

What is the 5th K sound?

Answer 41

End of sound, diastolic pressure

Question 42

What sound does aortic stenosis produce?

Answer 42

systolic murmur

Question 43

What sound does mitral stenosis produce?

Answer 43

diastolic murmur

Question 44

What are pleural rubs and what can they be caused by?

Answer 44

mechanical vibrations, pleural friction due to inflammation or tumor

Question 45

What is lung wheezing?

Answer 45

mechanical resonance, obstruction of the air (athma)

Question 46

What are lung crackles?

Answer 46

Bubbling fluid through ducts (penumonia, bronchitis)

Question 47

What is crepitation in the lungs?

Answer 47

heart valves closing / opening

Question 48

What is the respiratory work?

Answer 48

Average energy invested to inhale and exhale a breathing gas

Question 49

What are the 3 types of lung sounds?

Answer 49

1. Mechanical vibrations (rubs) 2. Mechanical resonance (wheezing) 3. Bubbling through fluid (crackles)