Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

The Respiratory System > Mechanisms and Regulation of Breathing > Flashcards

Mechanisms and Regulation of Breathing Flashcards

1
Q

What is the order of structures from the trachea to the alveoli

A

Trachea - bronchi - bronchioles - alveoli

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

What surrounds the walls of alveoli

A

Elastin fibres

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

What does elastin allow

A

It allows recoil of the alveoli at the end of a normal breath. The alveoli can return to their normal shape and size.

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

In what direction does lung elastic recoil occur

A

Lung elastic recoil occurs inwards

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

In what direction does the chest elastic recoil occur

A

Chest elastic recoil occurs outwards.

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

What is it that means the lungs do not collapse

A

There ate equal and opposing forces outwards and inwards. The lungs recoil inwards and the chest recoils outwards at the end of a normal breath.

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

On inspiration is the pressure in the atmosphere or the alveolus greater

A

The pressure in the atmosphere is much greater than that in the alveoli. This allows gas to enter the lungs and inspiration to occur.

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

What happens to the diaphragm and external intercostal muscles on inspiration

A

The diaphragm relaxes and the external intercostal muscles contract to increase chest volume and decrease alveolar pressure to allow for the entry of air.

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

What is the mechanism of expiration

A

The pressure in the alveoli must be greater than that in the atmosphere to force air out of the alveoli. This happens as the lungs recoil inwards at the end of a normal breath (which is a passive process).

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

What takes longer, inspiration or expiration

A

The expiratory time is longer than the inspiratory time.

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

How is large or forced expiration different than normal

A

It is an active process. Normal expiration is passive and occurs due to elastic recoil.

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

What muscles are involved in large or forced expiration

A

The abdominal muscles contract to push the diaphragm upwards towards its normal dome configuration and internal intercostal muscles also contract.

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

What is the tidal volume

A

The depth of the inspiration-expiration wave form

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

What is the normal tidal volume in a healthy person

A

400ml to 800ml.

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

What is an abnormal respiratory frequency

A

Above 20 breaths per minute.

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

What is the minute ventilation

A

The tidal volume multiplied by the respiratory rate in litres per minute.

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

What is the normal minute ventilation

A

5 litres per minute.

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

What structure is the respiratory rhythm regulated by

A

The medulla

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

What is the most important part of the brain for the regulation of breathing

A

The medulla. If this was taken away breathing would stop all together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What control are the medulla and pons under

A

Autonomic control

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

What control is the cortex under

A

Voluntary control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What would happen to the breathing rhythm is the cortex was removed

A

Rhythmical breathing continues but cannot be adjusted voluntarily.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the action of expiratory medullary neurons on inspiratory medullary neurons

A

Expiratory medullary neurons inhibit the inspiratory medullary neurons.

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

What is the action of inspiratory medullary neurons on expiratory medullary neurons

A

Inspiratory medullary neurons activate expiratory medullary neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does exaggerated inspiration lead to
Exaggerated expiration
26
What are four tings which change the basic breathing pattern
- Inhalation of noxious substances - Sleep - Exercise - Speech
27
Where do feedback inputs come from for respiratory rhythm
Lung receptors and chemoreceptors
28
What are the three types of lung receptors
- Slowly adapting receptors - Rapidly adapting receptors - C-fibre endings.
29
What are the two types of chemoreceptors
- Central chemoreceptors | - Peripheral chemoreceptors
30
What are lung receptors sensitive to
Neurological input from the vagus nerve
31
What are chemoreceptors sensitive to
Chemical changes such as changes in oxygen and carbon dioxide concentrations.
32
What is the difference in response to CO2 levels in central and peripheral chemoreceptors
Central chemoreceptors respond slowly to arterial carbon dioxide concentration while peripheral chemoreceptors respond rapidly to changes in arterial carbon dioxide.
33
What happens if you remove the feedback through the vagus nerve from the lungs
Breathing becomes slow and deep.
34
What happens if you stimulate the vagus nerve
Breathing is rapid and shallow.
35
What is an example of a slowly adapting receptor in the lungs
Stretch receptors
36
What do stretch receptors do
They are receptive to mechanical strain and are slow firing. They help to initiate expiration and prevent over inflation of the lungs.
37
What is meant by "The Hering-Breuer Inflation Reflex"
prolonged inspiration leads to prolonged expiration.
38
How are rapidly firing receptors different to slowly adapting receptors
They set off a burst of firing and are not regularly continuous over a long period of time.
39
What do rapidly firing receptors do
They initiate cough and bronchoconstriction.
40
Which fibres are myelinated
Afferent fibres for rapdidly adapting receptors and afferent fibres for slowly adapting receptors.
41
Which fibres are not myelinated
C-fibres
42
How are C-fibres stimulated
By increased interstitial fluid (oedema) and inflammatory mediators. they are sensitive to inflammation in the lungs.
43
Where is the site that signals are relayed to the medulla
The bifurcation of the common carotid arteries
44
What nerve are signals sent through to the medulla from the site at the bifurcation of the common carotid arteries
The glossopharyngeal nerve.
45
Which nerve are signals from the arch of the aorta relayed through to the medulla
The vagus nerve
46
What is the action of central chemoreceptors on the medulla when there is increased carbon dioxide
They act indirectly by acidifying cerebrospinal fluid and causing breathing to change by increased ventilation to get rid of the excess carbon dioxide.
47
What is the normal arterial oxygen
Around 13/14kPa.
48
At what partial pressure does low oxygen become significant
Below 8kPa as the saturation of haemoglobin begins to fall.
49
Why would you not give high flow oxygen to a patient with COPD who has chronic hypoxia
Because the drive for this person to breathe comes from the low concentration to oxygen since the normal sensitivity to high carbon dioxide levels is reduced. Giving oxygen means that the drive to breathe no longer exists so there is hypoventilation and a further increase in arterial CO2. This can lead to death.
50
What is obstructive sleep apnoea
the drive to breathe during the day comes from the midbrain neural activity which also controls the muscles of the upper airway. At night the drive to breathe decreases and as a result people can also lose control of their upper airway, meaning it can come restricted or obstructed. This is obstructive sleep apnoea.
51
What are the two types of muscle activity in the upper airway
Phasic activity and tonic activity
52
What happens in phasic activity of the upper airway
There is contraction of the upper airway muscles, opening of the upper airway and facilitation of inward flow.
53
What happens in tonic activity
There is continuous background activity.
54
Why may the upper airways collapse during sleep
There is loss of tonic activity of the upper airway.
55
What are some examples of drugs which are breathing suppressants
- Almost all anaesthetics - Analgesics - Sedatives - e.g. benzodiazapines.
56
What are examples of breathing stimulants
Direct breathing stimulants include doxapram and indirect include beta 2 agonists such as bronchodilators.
57
What is the alveolar pressure compared to the atmospheric pressure at the end of a normal breath out
At the end of a normal breath out the alveolar and atmospheric pressures are equal as there is an open connection between them and there is no airflow in or out of the lungs at this point.
58
Why does the chest wall have elastic recoil outwards at the end of a normal breath
To resist distortion inwards from its natural resting shape.
59
What are the two inspiratory muscles
The diaphragm and the external intercostal muscles.
60
On inspiration is the pleural pressure positive or negative relative to the atmospheric pressure
The pleural pressure becomes more negative than the atmospheric pressure and this negative pressure is transmitted to the alveoli.
61
In which direction does air flow on inspiration and why does this happen
Air flow into the lungs down the pressure gradient between the mouth and the alveoli.
62
Is the pressure in the alveoli positive or negative upon expiration
On expiration, the pressure in the alveoli is positive (compared to it being negative on expiration).
63
In which direction does air move on expiration and why does this happen
Air moves from the alveoli to the mouth down a pressure gradient. On expiration the pressure in the alveoli is greater than that in the atmosphere.(this is compared to inspiration where the pressure in the atmosphere is greater than that in the alveoli).
64
What are the two expiratory muscles (for forced or large expiration)
The internal intercostal muscles and the abdominal muscles.
65
What limits the maximum airflow in expiration
Compression of small intrapulmonary airways by surrounding alveoli.
66
What controls the rhythmical contraction and relaxation of the respiratory muscles
The central nervous system.
67
What would happen to breathing if the upper pons region of the brain was removed
This would result in slow, gasping breaths.
68
What is it thought that neurons in the upper pons region do
Help to control breathing
69
What would happen on complete removal of the pons
This would restore rhythmical breathing.
70
Where is the basic rhythm of breathing generated
The medulla
71
What are the three groups of respiratory neurons in the medulla and pons
- The ventral respiratory group (VRG) - The dorsal respiratory group (DRG) - The pontine respiratory group (PRG)
72
Which types of neurons for breathing are in the ventral respiratory group
Both expiratory and inspiratory neurons.
73
Which types of neurons for breathing are in the dorsal respiratory group
Predominantly inspiratory neurons.
74
Which types of neurons for breathing are in the pontine respiratory group
Neurons active in both inspiratory and expiratory phases.
75
What is the functional model of the mechanism of breathing
- Discharge from the inspiratory neurons activates the respiratory muscles via spinal motor nerves resulting in inspiration. - Expiratory neurons fire and inhibit the inspiratory neurons. - Nerve impulses to the inspiratory muscles stop and passive expiration occurs. - If forceful expiration is required, expiratory neuron activity also activates expiratory muscles. INSPIRATORY NEURONS ACTIVATE EXPIRATORY NEURONS EXPIRATORY NEURONS INHIBIT INSPIRATORY NEURONS.
76
Where are central chemoreceptors located
The ventrolateral surface of the medulla
77
Where are peripheral chemoreceptors located
Carotid bodies.

The Respiratory System (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions