Respiratory Physiology - Lung Volumes Flashcards Preview

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Flashcards in Respiratory Physiology - Lung Volumes Deck (11)
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1
Q

Tidal volume (TV)?

A
  1. Volume inspired or expired with each breath at rest
  2. 500ml in males,
  3. 350ml in females
2
Q

Inspiratory reserve volume (IRV) ?

A
  1. 2.3L
  2. Maximum volume of air that can be inspired at the end of a normal tidal inspiration
  3. Inspiratory capacity = TV + IRV
3
Q

Expiratory reserve volume (ERV) ?

A
  1. 750ml
  2. Maximum volume of air that can be expired at the end of a normal tidal expiration
4
Q

Residual volume (RV) ?

A
  1. 1.2L
  2. Volume of air remaining after maximal expiration
  3. Increases with age
  4. RV = FRC - ERV
5
Q

Vital capacity (VC) ?

A
  1. 5L
  2. Maximum volume of air that can be expired after a maximal inspiration
  3. 4,500ml in males, 3,500 mls in females
  4. decreases with age
  5. VC = inspiratory capacity + ERV
6
Q

Total lung capacity (TLC) ?

A
  • The sum of the vital capacity + residual volume
7
Q

Physiological dead space (VD)?

A
  1. VD = tidal volume * (PaCO2 - PeCO2) / PaCO2
  2. Where PeCO2 = expired air CO2
8
Q

How is lung compliance defined?

A
  • Change in lung volume per unit change in airway pressure
9
Q

Causes of INCREASED compliance?

A
  1. Age
  2. Emphysema - this is due to loss alveolar walls and associated elastic tissue
10
Q

Causes of DECREASED compliance?

A
  1. Pulmonary oedema
  2. Pulmonary fibrosis
  3. Pneumonectomy
  4. Kyphosis
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