Breathing Mechanics and Lung Capacity Flashcards
(13 cards)
What is the normal atmospheric pressure?
760 mm Hg
What is lung pressure at rest?
760 mm Hg
What is lung pressure during inspiration?
758 mm Hg
What is lung pressure during expiration?
760-762 mm Hg
What happens during inspiration?
-Nerves impulses tell the diaphragm and intercostal muscles to contract.
-Diaphragm contracts down to compress digestive organs.
-Intercostal muscles lift the rib cage up and out.
-Internal volume goes up while pressure goes down.
What happens during expiration?
-Diaphragm relaxes allowing the digestive organs to recoil.
-Intercostal muscles also relax allowing the rib cage to return to rest postion.
-Lung volume returns to rest volume.
-As lung volume goes down, pressure goes up.
What is tidal volume?
The amount of air that enters or leaves the lungs during passive respiration.
What is vital capacity?
The maximum amount of air that can be brought into the lungs with one inspiration.
What is a normal tidal volume?
500 ml
What is normal vital capacity?
4800 ml
What is normal residual volume?
1200 ml
What is total lung capacity?
6000 ml
How much air remains in the lungs at any time and why?
1200 ml to keep the lungs inflated and maintain homeostasis.
