Ventilation Flashcards
(2 cards)
Inhalation steps
- diaphragm contracts (moves downwards / flattens)
- external intercostal muscles contract
- rib cage moves upwards and outwards
- increased volume of thoracic cavity
- decreased pressure of thoracic cavity
- pressure of thoracic cavity < atmospheric pressure (of rest of body)
- so air rushes into lungs / thoracic cavity through nose / mouth
Exhalation steps
- external intercostal muscles relax
- rib cage moves downwards and inwards
- diaphragm stays convex / relaxes:
- decreased volume of thoracic cavity
- increased pressure of thoracic cavity
- pressure of thoracic cavity > atmospheric pressure (of rest of body)
- so air rushes out of lungs