Respiration 2 movement of air Flashcards

Semester 1 year 1

1
Q

What does the distensibility of the lungs mean (measure of elasticity)?

A

The ease with which the lungs and thorax expand during pressure changes

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

How do you measure distensibility?

A

Change in volume / change in pressure

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

What is the effect on inspiration and expiration when there’s a high or low compliance?

A
  • low compliance = more work required to inspire
  • high compliance = often involves more difficulty expiring (loss of elastic recoil)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is transpulmonary pressure?

A

The pressure gradient between the intrapleural space + the alveoli

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

What is the ‘anatomical’ component of elastic recoil in the lungs?

A

Elastic nature of the cells + extracellular matrix

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

What is the elastic recoil in the lung due to?

A

Surface tension generated at the air-fluid interface

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

What results in surface tension?

A

Differences in forces on water molecules at air/water interfaces

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

How are the forces balanced in a gas bubble?

A

Balance between the pressure exerted by the gas + the surface tension at the gas/water border

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

What is the equation that describes the balance of forces in a gas bubble?

A
  • Laplace’s equation
  • P = 2T / r
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is surface tension constant or not?

A

Constant

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

How does the volume of the air sacs in the lungs differ?

A

Pressure in larger sacs < smaller sacs

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

How does air flow between the alveoli?

A
  • from smaller to larger alveoli
  • leads to their collapse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do smaller alveoli overcome collapsing?

A

Production of surfactant

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

What produces surfactant?

A
  • type II pneumocytes
  • composed of a number of lipids + proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the functions of surfactant and how does it do it?

A

-prevent alveolar collapse - decrease surface tension
-alveolar size regulation - spread of surfactant slows rate of inflation
-increases compliance - lungs can inflate more easily
-prevents oedema - reduces fluid entering alveoli

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

What is anatomical dead space?

A

Volume of conducting airways

17
Q

What is physiological dead space?

A

Volume of lungs not participating in gas exchange

18
Q

What is vital capacity?

A

-fullest inhale followed by fullest exhale, then it’s the volume remaining in the lungs
-from highest peak to next trough

19
Q

What is FEV1?

A

-forced expiratory volume in 1 second
-amount that’s forcibly exhaled in 1 second

20
Q

What is inspiratory reserve volume?

A

-breathe in normally, then breath in without breathing out
-from peak of regular breathing to peak of max inhale (highest peak)

21
Q

What is expiratory reserve volume?

A

-breathe out normally, then breathe out again without breathing in
-from trough of regular breathing to trough of max exhale

22
Q

What is tidal volume on a graph?

A

From peak to trough of regular breathing

23
Q

What is residual volume on a graph?

A

From trough of max exhale to 0

24
Q

What is total lung capacity on a graph?

A

From 0 to peak of max inhale

25
What is inspiratory capacity on a graph?
From trough of regular exhale to peak of max inhale
26
What is functional residual capacity on a graph?
From 0 to trough of regular exhale
27
What is the flow of air into or out of the lungs proportional and inversely proportional to?
-proportional to pressure gradient -inversely proportional to resistance
28
How do you calculate the flow of air into or out of the lungs?
change in pressure / resistance
29
What law determines the impact of resistance on flow?
Poiseuille's law
30
What is airway resistance proportional or inversely proportional to?
-proportional to gas viscosity + tube length -inversely proportional to the 4th power of the radius
31
How do you calculate the airway resistance?
(8 / pi) x [(gas viscosity x length) / r^4]
32
What do small changes in airway diameter have a big impact on?
Resistance + so flow rate
33
How do you calculate total resistance when resistance is in series + parallel?
-in series: Rt = R1 + R2 + R3 + ... -in parallel: 1/Rt = 1/R1 + 1/R2 + 1/R3 + ...
34
What factors impact on airway resistance?
-airway diameter -increased mucus secretion - reduce airway diameter - oedema - increased fluid retention in lung tissue causes swelling + narrowing of airways -airway collapse - narrows airway
35
What controls bronchial smooth muscle?
-autonomic nervous system -humoral factors
36
How does the autonomic nervous system control the bronchial smooth muscle?
-parasympathetic - ACh released from vagus, acts on muscarinic receptors leading to constriction -sympathetic - release of norepinephrine from nerves - weak agonist leads to dilation
37
How do humoral factors control the bronchial smooth muscle?
-epinephrine circulating in blood - better agonist leads to dilation -histamine - released during inflammatory processes + leads to constriction