What is Laplace law in respiratory system?

Law of Laplace (P = 2γ/r) states that the pressure difference between the inside and the outside of an elastic sphere (“Laplace pressure”) is inversely proportional to the radius.

What prevents the alveoli from closing?

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 force keeps the alveoli in the lungs open?

The alveoli are the tiny air sacs in the lungs where gas exchange happens. And their walls are lined by a thin film of water, which creates a force at their surface called surface tension.

Do alveoli expand and contract?

Alveoli are microscopic balloon-shaped structures located at the end of the respiratory tree. They expand during inhalation, taking in oxygen, and shrink during exhalation, expelling carbon dioxide.

What is Laplace’s law and how is it applied to the properties of alveoli?

Laplace’s law as it applies to bubbles of unequal radius attached to a Y-tube. The pressure (P) in a bubble is equal to 4 times the surface tension (T) divided by the radius (r). As applied to the grape-like alveolus, where only the inner wall has a liquid surface exposed to gas, the formula is P = 2T/r.

How does alveolar surface tension affect 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.

Why don t the smaller airways and alveoli collapse?

The hydrophilic ends are water insoluable and face towards the air and pull away from the water. The net result is that the surface tension of the lungs from water is reduced so that the lungs can still inflate and deflate properly without the possibility of collapse from surface tension alone.

What force causes oxygen to enter the alveoli?

What force causes oxygen to enter the alveoli? Positive pressure; air is forced in.

Does alveolar surface tension determine lung compliance?

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 do the lungs balance for differences in alveolar size?

This means that the amount of pressure in the larger bubbles will be higher than in smaller ones; in the lung where bubbles are interconnected, this pressure difference will cause flow to the smaller alveoli, thus keeping all the alveoli about the same size.

Why is surface tension in the alveoli bad?

Respiratory Failure Increased surface tension increases cohesion within the alveoli, pulling the alveoli closed. This occurs in respiratory distress syndrome in premature newborns because until around 36 weeks of gestation the fetus produces immature surfactant that inadequately reduces surface tension.

What are the medical implications of Laplace law of surface tension?

The Laplace Bubble Law has medical implications. The heart is like a bubble of muscle creating tension on the fluid inside it (blood). An enlarged heart (bigger R) will require more tension (bigger γ) to create the same pressure differential.