Search results
Results from the WOW.Com Content Network
Lung compliance is influenced by a variety of primary abnormalities of lung parenchyma, both chronic and acute. Airway resistance is typically increased by bronchospasm and airway secretions. Chest wall compliance can be decreased by fixed abnormalities (e.g. kyphoscoliosis , morbid obesity ) or more variable problems driven by patient ...
Static lung compliance is the change in volume for any given applied pressure. [1] Dynamic lung compliance is the compliance of the lung at any given time during actual movement of air. Low compliance indicates a stiff lung (one with high elastic recoil) and can be thought of as a thick balloon – this is the case often seen in fibrosis.
In fluid dynamics, the Hagen–Poiseuille equation is a physical law that gives the pressure drop in a fluid flowing through a long cylindrical pipe. The assumptions of the equation are that the flow is laminar viscous and incompressible and the flow is through a constant circular cross-section that is substantially longer than its diameter.
The normal relaxed state of the lung and chest is partially empty. Further exhalation requires muscular work. Inhalation is an active process requiring work. [4] Some of this work is to overcome frictional resistance to flow, and part is used to deform elastic tissues, and is stored as potential energy, which is recovered during the passive process of exhalation, Tidal breathing is breathing ...
Flux F through a surface, dS is the differential vector area element, n is the unit normal to the surface. Left: No flux passes in the surface, the maximum amount flows normal to the surface.
In healthy lungs where the alveolar dead space is small, Fowler's method accurately measures the anatomic dead space using a single breath nitrogen washout technique. [4] [5] The normal value for dead space volume (in mL) is approximately the lean mass of the body (in pounds), and averages about a third of the resting tidal volume (450-500 mL).
If the fluid flow is irrotational, the total pressure is uniform and Bernoulli's principle can be summarized as "total pressure is constant everywhere in the fluid flow". [1]: Equation 3.12 It is reasonable to assume that irrotational flow exists in any situation where a large body of fluid is flowing past a solid body. Examples are aircraft in ...
Although total liquid ventilation (TLV) with completely liquid-filled lungs can be beneficial, [9] the complex liquid-filled tube system required is a disadvantage compared to gas ventilation—the system must incorporate a membrane oxygenator, heater, and pumps to deliver to, and remove from the lungs tidal volume aliquots of conditioned perfluorocarbon (PFC).