Surfactant Action
Surfactant Action - Related Videos
09:34
Extraction and Characterization of Surfactants from Atmospheric Aerosols
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Cited by 26 •
2017
Methods are presented for the targeted extraction of surfactants present in atmospheric aerosols and the determination of their absolute concentrations and surface tension curves in water, including their Critical Micelle Concentration (CMC).
07:20
Lavage-induced Surfactant Depletion in Pigs As a Model of the Acute Respiratory Distress Syndrome (ARDS)
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Cited by 21 •
2016
Repeated pulmonary lavages in anesthetized pigs induce lung injury resembling major aspects of human acute respiratory distress syndrome (ARDS). For this purpose the lungs are repeatedly lavaged with 0.9% saline at 37 °C. The goal of the protocol is a reproducible mitigation of gas exchange and hemodynamics for research in ARDS.
10:28
Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids
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Cited by 15 •
2014
This paper demonstrates the experimental procedure to measure terminal settling velocities of spherical particles in surfactant-based shear thinning viscoelastic fluids. Fluids over a wide range of rheological properties are prepared and settling velocities are measured for a range of particle sizes in unbounded fluids and fluids between parallel walls.
12:33
Corticospinal Excitability Modulation During Action Observation
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Cited by 22 •
2013
Single-pulse transcranial magnetic stimulation over the primary motor cortex, neuronavigation, and registration of electromyographic activity of hand muscles were used in this study to explore corticospinal excitability while participants were observing action sequences.
01:14
Action Potential
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2025
Neurons communicate by firing action potentials—the electrochemical signal that is propagated along the axon. The signal results in the release of neurotransmitters at axon terminals, thereby transmitting information to the nervous system. An action potential is a specific "all-or-none" change in membrane potential that results in a rapid spike in voltage. Membrane potential in neurons Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
FAQs
During expiration, the alveolar air-liquid interface would otherwise create conditions that favor greater surface tension. Pulmonary surfactant lowers that tension during this phase, helping alveoli remain stable rather than collapse. This stabilization reduces the effort required to move air, making surfactant action essential for maintaining effective breathing across the respiratory cycle.
Phospholipids and specialized proteins form the pulmonary surfactant mixture that operates at the alveolar air-liquid interface. This composition enables the lining layer to modify interfacial tension efficiently. Their combined presence is therefore relevant to alveolar stability and respiratory mechanics, rather than surfactant function being attributable to a single molecular component.
When surfactant is inadequate, alveolar stability is compromised, promoting collapse and impairing gas exchange. The resulting problem is not limited to the interface itself: reduced stability also increases the work required for breathing. This connection helps explain why disorders involving insufficient surfactant can produce both ineffective oxygen transfer and greater respiratory effort.
Surfactant replacement therapy is particularly relevant for premature infants with respiratory distress syndrome, where inadequate surfactant contributes to pulmonary dysfunction. It is used in selected patients rather than as a universal treatment. Its clinical rationale is to restore surface-active function at the alveolar interface, addressing a mechanism that can worsen collapse and gas-exchange impairment.
In selected patients, replacement therapy can improve lung compliance and oxygenation. These outcomes reflect two important aspects of respiratory performance: how effectively the lungs function during breathing and how well oxygen transfer occurs. Monitoring such changes helps indicate whether restoring surfactant function has benefited the patient's pulmonary condition.
Surfactant action links events at the alveolar air-liquid interface with clinically important respiratory outcomes. Changes in this process can be associated with alveolar collapse, impaired gas exchange, and increased work of breathing. This connection explains why lung compliance and oxygenation are relevant outcomes when clinicians evaluate disorders involving surfactant or consider replacement therapy.