Lecture 1: Mechanics of Breathing Flashcards
1
Q
what are the inspiratory mucles
A
- diaphragm
- external intercostals
- accessory muscles, eg scalene and sternomastoids
2
Q
what is transpulmonary presssure
A
chest wall exerts a distending pressure on the pleural space
3
Q
what is hysteresis
A
difference between lung compliance during inspiration and expiration
4
Q
what disease involves decreased compliance
A
- pulmonary fibrosis
- alveolar walls are stiff and scarred
5
Q
what disease involves increased compliance
A
emphysema
6
Q
what is caused by surfactant deficiency
A
respiratory distress syndrome
7
Q
what does surfactant do
A
- increases lung compliance
- promotes alveolar stability
- prevents alveolar collapse
- reduces hydrostatic pressure in tissue outside capillaries to keep lungs dry
8
Q
what factors affect airway resistance
A
- inflammation + mucus decrease radius
- bronchodilators + steroids increase radius
- gas density, eg in diving
9
Q
what is the work of breathing
A
the amount of energy or O2 required by respiratory muscles to produce enough respiration to meet metabolic demands of the body
