Compliance depends on the elasticity and surface tension of the lungs. Compliance is inversely related to the elastic recoil of the lungs, so thickening of lung tissue will decrease lung compliance.
How does surface tension affect lung compliance?
More elastic fibers in the tissue lead to ease in expandability and, therefore, compliance. Surface tension within the alveoli is decreased by the production of surfactant to prevent collapse. Compliance is more easily achieved by decreasing surface tension.
Increased surface tension increases cohesion within the alveoli, pulling the alveoli closed. The alveolar cells produce a specialized liquid, surfactant, that decreases the surface tension in the airways reducing the amount of energy required to expand the lungs.
Does alveolar surfactant increase compliance?
As described earlier, surfactant helps in reducing surface tension and thereby increases compliance of the lung. An absence of the surfactant leads to a decrease in pulmonary compliance, and this condition is called newborn respiratory distress syndrome.
Increased compliance can be present where there is degeneration of lung tissue. Degenerative lung tissue diseases (eg emphysema) make it harder for the lungs to expand, and harder to exhale as there is less elastic recoil.
What determines lung compliance quizlet?
What determines lung compliance? It is determined by destinsibility of the lung tissue and aveolar surface tension. You just studied 72 terms!
What causes reduced lung compliance?
Common causes of decreased lung compliance are pulmonary fibrosis, pneumonia and pulmonary edema. In an obstructive lung disease, airway obstruction causes an increase in resistance. During normal breathing, the pressure volume relationship is no different from in a normal lung.
Why reducing surface tension of the alveoli is important?
By lowering and varying surface tension as a function of alveolar size (radius), lung surfactant makes equilibrium pressures more equal in different sized alveoli. As a result, small airsacs resist collapse during expiration, and large alveoli do not over-inflate during inspiration.
What are the effects of surface tension?
Due to the surface tension, small objects will “float” on the surface of a fluid, as long as the object cannot break through and separate the top layer of water molecules. When an object is on the surface of the fluid, the surface under tension will behave like an elastic membrane.
How does pulmonary surfactant reduce surface tension?
By adsorbing to the air-water interface of alveoli, with hydrophilic head groups in the water and the hydrophobic tails facing towards the air, the main lipid component of surfactant, dipalmitoylphosphatidylcholine (DPPC), reduces surface tension.
What is alveolar surface tension?
The primary determinant of lung recoil is surface tension, which is a force imposed by water molecules at the surface of liquids. It occurs whenever there is an air-liquid interface, as in the case of the interior lining of alveoli, and acts to minimize the surface area.
Which of the following reduces alveolar surface tension?
Surfactant. Surfactant is a complex mixture of phospholipids and surfactant proteins that reduces alveolar surface tension.
Which factor determines pulmonary ventilation?
In this section, you will examine the factors that regulate pulmonary ventilation, including pressure gradients, surface tension, airway resistance and compliance of the lungs.
What is lung compliance quizlet?
What is lung compliance? A measure of how easily the lung can be stretched out or inflated. Therefore, compliance is similar to distensibility.
What does compliance measure in terms of lung function quizlet?
inspiratory capacity. the maximum amount of air that can be inspired after expiration of a normal breath at rest. What does compliance measure in terms of lung function? measures how well the lung can expand and return to shape.
Which of the factors increases airway resistance and causes bronchoconstriction?
Airway resistance is usually increased with obesity. This is partially related to the narrowing of small airways that occurs at lower lung volumes.
What material normally prevents lung alveoli from collapsing and preventing gas exchange?
Surfactant is released from the lung cells and spreads across the tissue that surrounds alveoli. This substance lowers surface tension, which keeps the alveoli from collapsing after exhalation and makes breathing easy.
Which of these are the reasons to cause surface tension?
The surface tension arises due to cohesive interactions between the molecules in the liquid. At the bulk of the liquid, the molecules have neighboring molecules on each side. Molecules are pulling each other equally in all directions causing a net force of zero.
What happens when surface tension is reduced?
When the surface tension of the liquid reduces it will slowly start to evaporate and eventually behave like a gas. Was this answer helpful?
What is the purpose of surface tension?
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged.
What is surface tension and what conditions must exist for it to occur?
What is surface tension and what conditions must exist were to occur? Surface tension is the energy required to increase the surface area of a liquid that a given amount. The stronger the attraction between particles, the greater the surface tension.
What is the role of surface tension in everyday life?
The effects of surface tension are of central importance in many everyday phenomena: it causes small droplets of rain to stick to your windows, creates bubbles when you add detergent in your sink, and propels water-striding insects on the surface of ponds.
How does surface tension of the alveolar fluid affect ventilation?
Pulmonary Surfactant The force of surface tension in the lungs is so great that without something to reduce the surface tension, the airways would collapse after exhalation, making re-inflation during inhalation much more difficult and less effective. Collapse of the lungs is called alectasis.
Which of the following reduces alveolar surface tension quizlet?
Surfactant reduces surface tension, so that the alveoli in the lungs are able to expand.
How does a surfactant affect surface tension?
The surfactant reduces the surface tension of water by adsorbing at the liquid”gas interface. They also reduce the interfacial tension between oil and water by adsorbing at the liquid”liquid interface.
What is the role of surfactant in alveolar function?
It is established that pulmonary surfactant reduces surface tension at the air”water interface in the alveoli, thereby preventing collapse of these structures at end-expiration. In this manner, surfactant reduces the work associated with breathing.
What are the two main determinants of lung compliance?
Two factors determine lung compliance: elasticity of the lung tissue and surface tensions at air water interfaces. Two factors determine lung compliance ” elasticity of the lung tissue and surface tensions at air water interfaces.
What affects lung compliance?
Two factors determine lung compliance: elasticity of the lung tissue and surface tensions at air water interfaces. Two factors determine lung compliance ” elasticity of the lung tissue and surface tensions at air water interfaces.
How does alveolar ventilation work in ventilation perfusion coupling?
Ventilation perfusion coupling means that more blood flows past functional alveoli than past nonfunctional alveoli. The olfactory mucosal lining of the nasal cavity contains the receptors for the sense of smell.
Which results in an increase in lung compliance quizlet?
Surfactant lowers surface tension and increases lung compliance.
What is normal compliance of the lung?
Normal adult lung compliance ranges from 0.1 to 0.4 L/cm H20. Compliance is measured under static conditions; that is, under conditions of no flow, in order to eliminate the factors of resistance from the equation. Using this equation, total compliance of the lung and the chest wall becomes approximately 0.2 L/cm H20.
Which condition does the term compliance refer to?
Compliance is defined as. change in volume / change in pressure (L/ cm water) also compliance = 1 / elasticity (or stiffness)
What does alveolar ventilation refers to?
Alveolar ventilation is the exchange of gas between the alveoli and the external environment. It is the process by which oxygen is brought into the lungs from the atmosphere and by which the carbon dioxide carried into the lungs in the mixed venous blood is expelled from the body.
How is alveolar air different from inspired air?
How is alveolar air different than inspired air? Alveolar air has a higher PN2 than inspired air. Alveolar air has a lower PCO2 than inspired air. Alveolar air has a higher PO2 than inspired air.
Which condition does the term compliance refer to quizlet?
What does the term “compliance” mean? The expansibility of the lungs or thorax; a measure of the “ease” with which the lungs can expand. The change of lung volume per unit change of trans-pulmonary pressure, “V/”P. if compliance increases, is it harder or easier for the lungs to expand? easier.
Does breathing increase lung pressure?
During the process of inhalation, the lung volume expands as a result of the contraction of the diaphragm and intercostal muscles (the muscles that are connected to the rib cage), thus expanding the thoracic cavity. Due to this increase in volume, the pressure is decreased, based on the principles of Boyle’s Law.
How does pneumothorax affect lung volume and alveolar pressure when inspiratory muscles contract how does this affect air flow?
How does pneumothorax affect lung volume and alveolar pressure when inspiratory muscles contract? How does this affect air flow? A lung with a pneumothorax does not inflate because the intrapleural pressure is no longer subatmospheric. The lung is not held tightly against the thoracic wall and does not inflate.
Which factors can increase airway resistance in a client?
Bronchospasm, mucus plugging, and edema in the peripheral airways result in increased airway resistance and obstruction. Air trapping results in lung hyperinflation, ventilation/perfusion (V/Q) mismatch, and increased dead space ventilation.
How does surface tension affect lung compliance?
More elastic fibers in the tissue lead to ease in expandability and, therefore, compliance. Surface tension within the alveoli is decreased by the production of surfactant to prevent collapse. Compliance is more easily achieved by decreasing surface tension.
What factors affect alveolar gas exchange?
What causes increased lung compliance?
Increased compliance can be present where there is degeneration of lung tissue. Degenerative lung tissue diseases (eg emphysema) make it harder for the lungs to expand, and harder to exhale as there is less elastic recoil.
Which has highest surface tension?
Besides mercury, water has the highest surface tension for all liquids, which is due to the hydrogen bonding in water molecules. The surface tension of water causes water molecules at the surface of the liquid (in contact with air) to hold closely together, forming an invisible film.
Why is the surface tension also called surface energy?
The attractive force of the molecules present at the surface of a liquid towards each other is called the surface tension of that liquid. Surface energy is the equivalent attractive force present between the molecules at the surface of a solid substance.
What causes surface tension quizlet?
Surface tension forms because of water’s cohesive property which results from hydrogen bonding and water’s polarity. In cohesion, water molecules bond together and require a substantial amount of energy to break thus creating a high surface tension.
Which force is responsible for surface tension?
The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension.
Why does surface tension decrease with increasing concentration?
The surface tension decreases with increase in concentration. This is due to breaking of hydrogen bonds when surfactants are added in water, leading to higher adsorption at the air-water interface. This allows an increase in interfacial area without overall increase in energy [31].