46R. Respiratory - Overview of respiration and respiratory mechanics Flashcards
(42 cards)
what are the 4 steps in respiration
- ventilation
- Gas exchange between alveoli and blood
- Gas transport in the blood
- Gas exchange at the tissue level
what is ventilation
the mechanical process of moving gas in and out of the lungs
what is the gas exchange between alveoli and blood briefly
the exchange of O2 and CO2 between the air in the alveoli and the blood in the pulmonary capillaries
describe the gas transport in the blood briefly
the binding and transport of O2 and CO2 in the circulating blood
what is the gas exchange at the tissue level briefly
the exchange of O2 and CO2 between the blood in the systemic capillaries and the body cells
quiet inspiration and expiration is collectively known as what
tidal volume
the process of quiet breathing is under automatic control from what?
respiratory control centre
what are the lung mechanics in quiet respiration
Air is drawn into the airways by ACTIVE expansion of the thoracic cavity, which in turn expands the lungs
what is BOYLE’s Law
inverse relationship between pressure and volume of a gas
describe the changes in pressure during quiet inspiration
- contraction of inspiratory muscles
- chest wall and lungs stretch
- increased size of lungs makes intra-alveolar pressure fall
- then air enters the lungs down the pressure gradient until the intra-alveoli pressure becomes equal to atmospheric pressure
is inspiration passive or active
active
The increase in the size of the lungs make the intra-alveolar pressure to fall. WHY?
because air molecules become contained in a larger volume
what are the main muscles in inspiration
diaphragm and external intercostal
what are the two mechanics of ventilation with normal quiet inspiration
pump handle movement
bucket handle movement
pump handle movement
bucket handle movement
which is anterior and superior movement and which is lateral and superior
pump handle movement- anterior
bucket handle movement- lateral
what are the lung mechanics in quiet expiration
- air expelled from airways passively by relaxing muscles of inspiration
- reduces volume of thoracic cavity
- reduces volume of lunges
is expiration at rest passive or active
passive
describe the changes in pressure during quiet respiration
relaxation of inspiratory muscles
recoil of chest wall and lungs - elastic properties, return to pre inspiratory size
- as the lungs recoil, the space inside them gets smaller so intra-alveolar pressure rises
- air then moves from the high pressure out into the low pressure environment (outside the lungs)
- air continues to leave until lung pressure and atmospheric pressure are equal
what is the resting expiratory level
the point before you inspire, having just inspired
lungs- pull inward
chest wall - pulls outward
diaphragm - pulls downward
body wants to go back to this resting state
is inspiration active or passive
active
describe inspiration
muscles contract to allow the chest wall to overcome the inward pull of the lung recoil.
This helps the chest wall (increasing space) push out against the inward pull of the lungs.
is expiration active or passive
passive
describe expiration to me simply
muscles stop contracting
return to resting expiratory level
diaphragm moves back into resting position
inward pull of lung recoil
air leaves lungs as they are at higher pressure than outside
what creates surface tension on alveoli
they are lined with fluid
