2. Mechanics of breathing Flashcards

1
Q

What is tidal volume - TV ?

A

Volume of air breathed in and out of lung at each breath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is expiratory reserve volume- ERV ?

A

Maximum volume of air expelled from lungs at end of normal expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is inspiratory reserve volume- IRV ?

A

Maximum volume of air drawn into the lungs at end of normal inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is residual volume- RV ?

A

Volume of gas in the lungs at the end of maximal expirationCannot voluntarily expire it Stops alveoli collapsing Reduces work of breathing Provides volume of air that can allow gas exchange to take place between breaths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is vital capacity- VC ?

A

Total amount of air we expire TV + ERV + IRV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is functional residual capacity- FRC ?

A

Volume of air that is in our lungs at the end of normal expirationERV + RV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is total lung capacity- TLC ?

A

Volume of air in lungs after maximum inspiration VC + IRV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is inspiratory capacity- IC ?

A

Volume breathed in from quiet expiration to maximum inspirationTV + IRV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is forced vital capacity- FVC ?

A

The maximal volume of air that a subject can expel in one maximal expiration from a point of maximal inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is FEV1 -forced expiratory volume in one second ?

A

The maximal volume of air that a subject can expel in one second from a point of maximal inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is FEV1:FVC ?

A

Fraction of forced vital capacity expired in 1 second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Boyle’s law ?

A

states that the pressure exerted by a gas is inversely proportional to its volume (P a 1/V)gases move from areas of high pressure to areas of low pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Dalton’s law ?

A

States the total pressure of a gas is the sum of the pressures of the individual gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Charles law ?

A

States the volume occupied by a gas is directly related to the absolute temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Henry’s law ?

A

states that the amount of gas dissolved in a liquid is determined by the pressures of the gas and its solubility in a liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does the mechanics of breathing occur ?

A

Because the thoracic cavity changes volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Based on Boyle’s law when volume increases what happens to pressure ?

A

When volume increases = pressure decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Based on Boyle’s law when volume decreases what happens to pressure ?

A

When volume decreases = pressure increases

19
Q

What muscles are involved in normal inspiration ?

A

External intercostal musclesDiaphragm

20
Q

What accessory muscles are used in active (forced) inspiration ?

A

Scalenes Sternocleidomastoids

21
Q

Is expiration passive or active at rest ?

A

At rest expiration is passive

22
Q

What muscles are involved in forced expiration ?

A

Internal intercostals Abdominal muscles

23
Q

What happens to the diaphragm at rest ?

A

Relaxed

24
Q

What happens to the diaphragm during inspiration ?

A

Contracts and flattens Thoracic volume increases

25
Q

What happens to the diaphragm during expiration ?

A

RelaxesThoracic volume decreases

26
Q

What effect does the external intercostals have on the ribcage ?

A

Elevates ribs and sternum upwards and outwards

27
Q

What is the pump handle motion ?

A

During inspiration- increases anterior-posterior dimensions of the ribcage

28
Q

What is the bucket handle motion ?

A

During inspiration- increases lateral dimensions of ribcage

29
Q

What effect does the internal intercostals have on ribcage ?

A

Pull ribs and sternum inwards

30
Q

What happens to the airways during inspiration ?

A

Airways are pulled open by physical forces of inspiration

31
Q

What happens to airways during expiration ?

A

Airways are compressed by physical forces of expiration

32
Q

What is intrathoracic or alveolar pressure (PA) ?

A

pressure inside the thoracic cavity (inside lungs), may be positive or negative compared to atmospheric pressure

33
Q

What is intrapleural pressure (Pip) ?

A

pressure inside the pleural cavity, typically negative compared to atmospheric pressure (in healthy lungs)

34
Q

What is transpulmonary pressure (PT) ?

A

Difference between alveolar pressure and intrapleural pressure always almost positive as intrapleural pressure is negative (in health)PT = Palv - Pip

35
Q

Regarding pressure changes what does it mean if there is a volume of 0 ?

A

No difference between the pressure recorded and atmospheric pressure

36
Q

If there is a positive value what does this mean regarding the pressure ?

A

pressure is greater than atmospheric pressure

37
Q

What does it mean if pressure value is negative ?

A

Pressure is less than atmospheric pressure

38
Q

During the inspiratory phase what happens to alveolar pressure ?

A

Always less than atmospheric pressure

39
Q

During the expiratory phase what happens to alveolar pressure ?

A

Always greater than atmospheric pressure

40
Q

What happens when alveolar pressure is the same as atmospheric pressure ?

A

No air movement as there is no pressure gradient to push air either way

41
Q

Is intrapleural always more or less than atmospheric pressure ?

A

Always less

42
Q

What happens to intrapleural pressure during inspiration ?

A

Becomes more negative

43
Q

What happens to intrapleural pressure during expiration ?

A

Becomes less negative

44
Q

What are the factors that affect breathing ?

A

Bulk flow of air between the atmosphere and alveoli is proportional to the difference between the atmospheric and alveolar pressures and inversely proportional to the airway resistance F = (Patm- PA)/R At the end of an unforced expiration Between breaths Patm =PA, no air is flowing and the dimensions of the lungs and thoracic cage are stable as a result of the opposing elastic forces. The lungs are streched and are attempting to recoil, whereas the chest wall is compressed and attempting to move outward. This creates a sub atmospheric intrapleural pressure and hence a transpulmonary pressure that opposes the forces of elastic recoil Airway resistance determines how much air flows into the lungs at any given pressure difference between atmosphere and alveoli. The major determinant of airway resistnace is the radii of the airways