Respiratory System 2 - Ventilation Flashcards Preview

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Flashcards in Respiratory System 2 - Ventilation Deck (46)
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1
Q

Define minute ventillation

A

The volume of air experied in one minute (or per minute)

2
Q

Define respiratory rate

A

The frequency of breathing per minute

3
Q

Define alveolar ventilation

A

The volume of air reaching the respiratory zone per minute

4
Q

Define anatomical dead space

A

The capacity of the airways incapable of undertaking gas exchange

5
Q

Define alveolar dead space dead space

A

The capacity of the airways that should be able to undertake gas exchange but cannot

6
Q

Define physiological dead space

A

The sum of alveolar and anatomical dead space

7
Q

Define hypoventilation

A

Inefficient ventilation of the lungs unable to meet metabolic demand

8
Q

Define hyperventilation

A

Excessive ventilation of the lungs above metabolic demand

9
Q

Define hyperpnoea

A

Increased depth of breathing to meet metabolic demand

10
Q

Define hypopnoea

A

Decreased depth of breathing inadequate to meet metabolic demand

11
Q

Define apnoea

A

Cessation of breathing

12
Q

Define dyspnoea

A

Difficulty breathing

13
Q

Define bradypnoea

A

Abnormally slow breathing rate

14
Q

Define tachypnoea

A

Abnormally fast breathing rate

15
Q

Define orthopnoea

A

Positional difficulty in breathing when lying down

16
Q

Draw a lung volume time trace

A
  • Tidal volume
  • Inspiratory reserve volume
  • Expiratory reserve volume
  • Residual volume
  • Functional residual capacity
  • Inspiratory capacity
  • Vital capacity
  • Total lung capcity
17
Q

Define capacity

A

The sum of two or more volmes

18
Q

What is the inspiratory reserve volume?

A

The volume of air above tidal volume that would be in the lungs if you forced inhalation rather

19
Q

What is the tidal volume?

A

The volume of air exhaled or inhaled in one breath at rest

20
Q

What is the expiratory reserve volume?

A

The volume of air below tidal volume that would leave the lung following forced exhalation

21
Q

What is residual volume?

A

The volume of air left in the lungs following forced exhalation

22
Q

What is the functional residual capacity?

A

The volume of air left in the lungs following tidal exhalation
(Expiratory reserve volume + residual volume)

23
Q

What is insipratory capacity?

A

The air that enters the lungs following forced inhalation

24
Q

What is vital capacity?

A

The difference between the volume in the lungs following forced exhalation and the volume following forced inhalation

25
Q

What is total lung capacity?

A

The volume of air in the lungs following forced inhalation

26
Q

What affects lung volumes and capacities?

A
  • Body size
  • Fitness (primarily innate)
  • Age
  • Sex
  • Disease
27
Q

What is the respiratory zone?

A
  • The area of the bronchioles that enter the lung tissue and exchange gas
  • 16 generations
28
Q

What is the conducting zone?

A
  • The area of the trachea and bronchi where no gas exchange takes place
  • 16 generations
  • 150mL in adults
  • Equivalent to anatomical dead space
29
Q

Why is increased dead space bad?

A

It is a lot harder to get a good oxygen supply

30
Q

Describe how the pressure and volume change in tidal breathing

A
  • Initially there is a decrease in pressure, causing the volume to increase
  • Air enters so the volume increases more, while the pressure increases to normal
  • The pressure then increases, causing the volume to decrease as air moves out
  • Once air has moved, volume decreases so the pressure decreases to baseline
31
Q

At neutral position, following tidal expiration, what is the chest wall relationship?

A

The chest recoil (outwards) equals the lung recoil (inwards)

32
Q

How does inspiration occur in the chest wall relationship?

A

Inspiratory muscle effort increases chest recoil (outwards) causing it to surpass lung recoil so the volume increases

33
Q

How does expiration occur in the chest wall relationship?

A

Increased expiratory muscle effort causes lung recoil to surpass chest recoil, so the volume decreases.

34
Q

How can the pleural membranes affect breathing pathologically?

A
  • Intrapleural bleeding disrupts the chest lung relationship (haemothorax)
  • Perforated chest wall causes air to enter making the lung collapse (pneumotorax
  • Both of these disrupt the tight seal of the pleura
35
Q

What is negative pressure breathing?

A
  • At rest, to breathe in and out, the air moves due to changes in pressure
  • The pressure gradient is generated by changing the lung pressure in relation to air, as opposed to at the mouth being pushed up or down the trachea
  • This is like sucking a straw
36
Q

When does positive pressure breathing occur?

A
  • When the atmospheric pressure is above the alveolar pressure.
  • Caused by mechanical ventilation, and mouth to mouth
37
Q

Describe the three compartment model of the lung

A
  • Three pressures - alveolar, pleural, and atmospheric

- The pressure that causes us to breathe is the transmural pressure (pressure inside - pressure outside the lungs)

38
Q

How do volume time curves change in patients with a restrictive disease?

A
  • If there is a restrictive disease, the patient cant fill their lungs with as much air or for as long as a normal patient
  • Like a bear hug
39
Q

How do volume time curves change in patients with a obstructve disease?

A
  • If there is an obstructive disease, the patient will take a long time to reach the peak, and will breath in significantly less air
  • Like something covering your mouth
40
Q

Describe the procedure of volume time curve

A
  • Patient wears a noseclip
  • Patient inhales to total lung capcity
  • Wrap lip around the mouthpiece then exhale as hard and fast as possible until residual volume is reached or 6 seconds pass
41
Q

Describe the procedure of a peak flow test

A
  • Patient wears noseclip
  • Patient inhales to total lung capacity
  • Patient wraps lips round mouthpiece
  • Patient exhales as hard and fast as possible
  • Exhalation does not have to reach RV
  • Repeat at least twice and take highest measurement
42
Q

Describe the procedure used to make a flow-volume loop.

A
  • Patient wears noseclip
  • Patient wraps lips round mouthpiece
  • Patient completes at least one tidal breath (A&B)
  • Patient inhales steadily to total lung capacity (C)
  • Patient exhales as hard and fast as possible (D)
  • Exhalation continues until RV is reached (E)
  • Patient immediately inhales to TLC (F)
43
Q

What happens to the flow volume loop if there is an obstructive disease?

A
  • In a mild obstructve disease, there is displacement to the left and an indented curve (coving)
  • In a severe obstructive disease there is a shorter curve, displaced to the left with a larger indentation
44
Q

What happens to the flow volume loop is there us a restrictive disease?

A
  • Displaced to the right

- Narrower curve

45
Q

What happens to the flow volume loop in the three types if obstruction?

A
  • Variable extrathoracic obstruction causes a blunted inspiratory curve
  • Variable intrathoracic obstruction causes a blunted expiratory curve
  • Fixed airway obstruction causes a blunted expiratory and inspiratory curve
46
Q

Define pulmonary ventilation

A
  • The total volume of air inhaled in one breath

- Equal to the alveolar ventilation + dead space ventilation

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