Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y1 - Respiratory > Physiology 1: Ventilation (L-1&2) > Flashcards

Physiology 1: Ventilation (L-1&2) Flashcards

1
Q

What is internal respiration?

A
  • Intracellular

- Biochemical reactions converting food and oxygen into energy and carbon dioxide

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

What is external respiration?

A

The exchange of oxygen and carbon dioxide between the external environment and cells

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

List the steps of external respiration

A
  • Ventilation
  • Alveolar gas exchange
  • Transport in blood
  • Gas exchange at tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define ventilation

A

The mechanical process of moving gas in and out of the lungs

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

Define alveolar gas exchange

A

The exchange of oxygen and carbon dioxide between air in the alveoli and the blood in the pulmonary capillaries

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

Define gas transport in the blood

A

The binding and transport of oxygen and carbon dioxide in the blood

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

Define tissue gas exchange

A

The exchange of oxygen and carbon dioxide between the blood in systemic capillaries and cells

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

Which 4 body systems are involved in external respiration?

A
  • Respiratory system
  • Cardiovascular system
  • Hematology system
  • Nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What term describes the intake of gas into the lungs?

A

Inspiration

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

What term describe the outflow of gas from the lungs?

A

Expiration

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

Describe the relationship between intra-alveolar and atmospheric pressures to allow inspiration

A

For inspiration:

Intra-alveolar pressure must be less than atmospheric pressure

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

Describe the relationship between intra-alveolar and atmospheric pressures before inspiration

A

Intra-alveolar pressure is the same as atmospheric pressure

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

Describe Boyle’s Law

A
  • As the volume of a set amount gas increases, the pressure it exerts decreases
  • At a constant temperature

(At a constant temperature the pressure exerted by a gas varies inversely with the volume of the gas)

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

What forces hold the thoracic wall and lungs together?

A
  • Intrapleural fluid cohesiveness
  • Negative intrapleural pressure

(*INTRApleural not INTERpleural)

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

Are there physical connections between the thoracic wall and the lungs?

A

No, they are not linked

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

Describe intrapleural fluid cohesiveness

A
  • The water molecules in the intrapleural fluid resist being pulled apart
  • Pleural membranes stick together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe negative intrapleural pressure

A
  • Intrapleural pressure is sub-atmospheric
  • Creates a transmural pressure gradients across the lung wall and across the thoracic wall
  • Pulls lungs out towards thoracic wall, and pulls thoracic wall in towards lung

(*See L1 slide 13 for explanation)

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

Describe the pressures that are important in ventilation

A

Atmospheric

Intra-alveolar

Intrapleural (intrathoracic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the process of inspiration

A
  • Active process due to muscle contraction
  • Thorax volume is increased by contraction of the diaphragm and external intercostal muscles
  • Increased thorax volume –> increases the lung volume –> increase in alveolar volume
  • Decrease in alveolar pressure (Boyle’s Law), causing the influx of air down its conc. gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which muscle contracts to vertically expand the thoracic cavity?

A

Diaphragm

It flattens as it contracts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the effect of the contraction of the external intercostal muscles on the volume of the thoracic cavity

A

Increases it by elevating the ribs, causing:

  • Increase side to side dimension
  • Sternum to move anteriorly and superiorly, increasing the front to back dimension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe the process of expiration

A
  • Passive process due to muscle relaxation
  • The thoracic cavity and lungs recoil to their pre-inspiratory size
  • Lung recoil decreases alveolar volume
  • Increasing intra-alveolar pressure (Boyle’s Law)
  • Outflow of air down its conc. gradient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Which muscles relax during normal expiration

A
  • Diaphragm

- External intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Define a pneumothorax

A

When there is air in the pleural cavity

Abolishing the transmural pressure gradient

Can lead to a collapsed lung

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define a transmural pressure gradient

A

Transmural pressure gradient is the pressure gradient between two sides of a wall or separator

e.g. across the visceral pleura

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the types of pneumothorax

A
  • Spontaneous

- Traumatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe a spontaneous pneumothorax

A
  • Hole in the lung
  • Air moves down conc. gradient from lung into pleural cavity
  • Abolishing transmural pressure gradient
  • Lung collapses to its unstretched size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe a traumatic pneumothorax

A
  • Puncture in chest wall
  • Air moves down conc. gradient from atmosphere into pleural cavity
  • Abolishing transmural pressure gradient
  • Lung collapses to its unstretched size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What causes the lungs to recoil during expiration?

A
  • Elastic connective tissue

- Alveolar surface tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Describe alveolar surface tension

A
  • Attraction between the water molecules (surface tension) on the inner surface of the alveoli
  • This resists the expansion of the lungs
  • Important in lung recoil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Describe pulmonary surfactant

A
  • Mix of lipids and proteins
  • Secreted by type II alveolar cells
  • Lowers alveolar surface tension, by disrupting the water molecules interactions
  • Lowers the surface tension of smaller alveoli more than that of larger alveoli
32
Q

Describe the relationship between alveolar size and their tendency to collapse

A
  • Smaller the alveoli, the more likely it is to collapse

- Due to LaPlace’s Law

33
Q

What is newborn respiratory distress syndrome

A
  • Fetal lungs don’t produce enough surfactant until late pregnancy
  • Thus premature babies may not have enough
  • Causes difficulty with inspiration
34
Q

Describe alveolar interdependence

A
  • Alveoli exist in clusters
  • If one alveolus in the cluster starts to collapse it will stretch the surrounding alveoli
  • They will then recoil exerting expanding forces of the collapsing alveolus, opening it
35
Q

List the factors keeping alveoli open

A
  • Transmural pressure gradient
  • Pulmonary surfactant
  • Alveolar interdependence
36
Q

List the factors promoting alveolar collapse

A
  • Elasticity of lung connective tissue

- Alveolar surface tension

37
Q

List the accessory muscles of inspiration

A
  • Sternocleidomastoid
  • Scalenus
  • Pectoral
38
Q

When are the accessory muscles of inspiration used for ventilation?

A

Only during forceful inspiration

39
Q

List the muscles of active expiration

A
  • Abdominal muscles

- Internal intercostal muscles

40
Q

When are the muscles of active expiration used for ventilation?

A

During active expiration

41
Q

Define the role of the major muscles of inspiration

A
  • Contract every inspiration

- Their relaxation allows passive expiration

42
Q

What is used to measure the different lung volumes and capacities?

A

A spirometer

43
Q

Define tidal volume (TV)

Give an average value

A
  • Volume inspired and expired during a single ventilation

- 0.5L

44
Q

Define inspiratory reserve volume (IRV)

Give an average value

A
  • Extra volume of air that can be inspired over and above the tidal volume
  • 3L
45
Q

Define expiratory reserve volume (ERV)

Give an average value

A
  • Extra volume of air that can be actively expired by a maximal contraction beyond the tidal volume
  • 1L
46
Q

Define residual volume (RV)

Give an average value

A
  • The air remaining in the lungs after maximal expiration

- 1.2L

47
Q

Define inspiratory capacity (IC)

Give an average value

A
  • Maximum volume that can be inspired after a normal expiration
  • IC = TV+IRV
  • 3.5L
48
Q

Define functional residual capacity (FRC)

Give an average value

A
  • The total volume of air left in the lungs after a normal expiration
  • FRC = ERV+RV
  • 2.2L
49
Q

Define vital capacity (VC)

Give an average value

A
  • The maximum volume of air that can be moved out during a single breath following maximal inspiration
  • VC = IRV+TV+ERV
  • 4.5L
50
Q

Define total lung capacity

Give an average value

A
  • Maximum volume of air the lungs can hold
  • TLC = VC+RV
  • 5.7L
51
Q

Which volumes cannot be determined using spirometry?

A
  • Residual volume

- and thus total lung capacity and functional expiratory reserve

52
Q

Describe the effect on the lung’s residual volume if the lungs elastic recoil is decreased

A 
Less elastic recoil
=
Less can be expired
=
Increased residual volume
53
Q

List dynamic lung volumes and ratios that can be determined from volume/time curves

A
  • Forced vital capacity (FVC)
  • Forced expiratory volume in 1 second (FEV1)
  • FEV1/FVC
54
Q

Define forced vital capacity (FVC)

A

The max volume that can be forcibly expired from the lungs following a maximum inspiration

55
Q

Describe why vital capacity and forced vital capacity are different measurements

A
  • If healthy FVC and VC should be the same
  • If there is obstructive lung disease then VC>FVC
  • Due to difficulty in forcibly expelling the air
56
Q

Define forced expiratory volume in one second (FEV1)

A

The volume air that can be expired during the first second of a FVC determination

57
Q

Define the FEV1/FVC ratio

  • Give a normal % value
A
  • The proportion of the forced vital capacity that can be expired in the first second
  • Usually >70%
58
Q

Define normal FEV1/FVC ratios, with those displaying obstructive lung disease

A

Normal: >70%

Abnormal: <70%

e.g.
Low FEV1/FVC = obstructive, or a mix of obstructive and restrictive

59
Q

Describe the effect of restrictive lung disease on:

  • FVC
  • FEV
  • FEV1/FVC ratio
A

FVC:
- Lower than normal

FEV:
- Lower than normal

FEV1/FVC ratio:
- The same as normal (as FEV1 and FVC are both lower)

60
Q

Describe the effect of a combination of restrictive and obstructive lung disease on:

  • FVC
  • FEV
  • FEV1/FVC ratio
A

FVC:
- Lower than normal

FEV:
- Lower than normal

FEV1/FVC ratio:
- Lower than normal

61
Q

Give the equation for airway resistance

A

F=ΔP/R

F - flow, ΔP - pressure, R - resistance

62
Q

Airway radius is important in determining airway resistance

A

Remember it

63
Q

Describe the effect of parasympathetic stimulation on airway radius

A

Parasympathetic

Bronchoconstriction

(via M3 Muscarinic ACh receptors)

*(para constricts unlike most other places)

64
Q

Describe the effect of sympathetic stimulation on airway radius

A

Sympathetic

Bronchodilation

(via β2 Adrenoceptor)

*(sympathetic relaxes unlike most other places)

65
Q

With obstructive lung disease is inspiration or expiration harder?

A

Expiration is more difficult

66
Q

Describe dynamic airway compression

A
  • When intrapleural pressure increases during active expiration
  • Compression of airway and alveoli
67
Q

Is dynamic airway compression a problem in normal people?

A

No

Only in people with obstructive lung disease

68
Q

Describe how dynamic airway compression can cause increased airway compression, or collapse if obstructive lung disease is present

A
  • The driving pressure between the alveolus and airway is lost over the obstruction
  • Causes a drop in airway pressure in the proximal airway
  • Airways can compress or collapse due to higher expiratory pleural pressure
69
Q

What sort of lung disease is a peak flow meter useful for detecting

A

Obstructive lung disease

peak flow = FEV1

70
Q

Give examples of obstructive lung disease

A
  • COPD

- Asthma

71
Q

Describe pulmonary compliance

A
  • a measure of the effort required to expand lungs
  • Volume change per unit of pressure change
  • Less compliant = more work to produce a certain degree of inflation
72
Q

List factors that decrease pulmonary compliance

A
  • Pulmonary fibrosis
  • Pulmonary oedema
  • Lung collapse (pneumothorax)
  • pneumonia
  • Absence of surfactant
73
Q

Describe the impact and symptoms of a decreased pulmonary compliance

A
  • Greater pressure change required to increase lung volume by a set amount (stiffer lungs)
  • Use of accessory inspiratory muscles
  • May cause a restrictive pattern of lung volumes
74
Q

List factors that increase pulmonary compliance

A
  • Loss of elastic recoil (abnormal)
  • Emphysema (abnormal)
  • Increased age
75
Q

What factors can increase the work of breathing

A
  • Pulmonary compliance is decreased
  • Airway resistance is increased
  • Elastic recoil is decreased
  • When there is a need for increased ventilation

Y1 - Respiratory (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions