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The air rushes into the lungs through inhalation (inspiration) and is pushed out through exhalation (expiration). [2] During ventilation, the air movement is generated by the air pressure gradient between the atmosphere and the lungs produced by thoracic muscles and diaphragm contraction. Air is pushed in and out of the lungs as air flows from ...
The higher pressure will "win". Hence, the closure of the pulmonary valve (P 2) will be delayed since the pressure in the right ventricle is increased in inspiration, opposing the pressure in the pulmonary artery and keeping it open longer than in expiration. The change in A 2 is not that evident. Thus P 2 appears after A 2 in inspiration ...
Doing spirometry. Spirometry (meaning the measuring of breath) is the most common of the pulmonary function tests (PFTs). It measures lung function, specifically the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled.
Exhalation (or expiration) is the flow of the breath out of an organism. In animals, it is the movement of air from the lungs out of the airways , to the external environment during breathing . This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume.
Lung volumes. Functional residual capacity (FRC) is the volume of air present in the lungs at the end of passive expiration. [1] At FRC, the opposing elastic recoil forces of the lungs and chest wall are in equilibrium and there is no exertion by the diaphragm or other respiratory muscles.
Phase II of expiration is when the CO 2 within the lungs is forced up the respiratory tract on its way to leave the body, which causes mixing of the air from the dead space with the air in the functional alveoli responsible for gas exchange. Phase III is the final portion of expiration which reflects CO 2 only from the alveoli and not the dead ...
Wheezes, describing a continuous musical sound on expiration or inspiration. A wheeze is the result of narrowed airways. Common causes include asthma and emphysema. [20] Rhonchi (an increasingly obsolete term) characterised by low pitched, musical bubbly sounds heard on inspiration and expiration. Rhonchi are the result of viscous fluid in the ...
Airway resistance can also vary between inspiration and expiration: In emphysema there is destruction of the elastic tissue of the lungs which help hold the small airways open. Therefore, during expiration, particularly forced expiration, these airways may collapse causing increased airway resistance.