Lung surfactants

[Audio] Today I am going to explain the topic of lung surfactants.

[Audio] Introduction Lung surfactants are a mixture of lipids and proteins that are produced by specialized cells called type II alveolar cells in the lungs..

[Audio] Here's the diagram showing type 1 and 2 alveolar cells secreting surfactants.

[Audio] Functions The main function of lung surfactants is to reduce surface tension at the air-liquid interface in the alveoli, the small air sacs in the lungs where gas exchange takes place. Without surfactant, the surface tension in the alveoli would be high, making it difficult for them to inflate during inhalation and causing them to collapse during exhalation. This would lead to a condition known as respiratory distress syndrome (RDS), which is particularly Common in premature infants..

[Audio] When we breathe in, air enters the lungs and fills the alveoli, which are lined with a thin layer of fluid. This fluid contains molecules with strong cohesive forces, which create surface tension that tends to collapse the alveoli. However, the presence of lung surfactants reduces this surface tension, making it easier for the alveoli to expand and preventing them from collapsing during exhalation. In addition to their role in reducing surface tension, lung surfactants also have other important functions, including helping to maintain the elasticity of the lung tissue and acting as a barrier against inhaled pathogens and environmental toxins..

[Audio] Next is the importance of lung surfactants Lung surfactants are essential for the proper functioning of the lungs and overall respiratory health. Here are some of the key reasons why lung surfactants are important: 1.Preventing lung collapse: As Imentioned earlier, lung surfactants reduce the surface tension at the air liquid interface within the alveoli of the lungs. This helps to prevent the collapse of the alveoli during exhalation, which is essential for efficient gas exchange and maintaining proper lung function..

[Audio] This diagram shows how normal alveoli and a collapsed Alveoli look like.

[Audio] 2. Improving gas exchange: By reducing surface tension, lung surfactants help to increase the surface area available for gas exchange within the alveoli. This allows for more efficient oxygen uptake and carbon dioxide removal during respiration. 3.Supporting lung elasticity: Lung surfactants also play a key role in maintaining the elasticity of the lung tissue, which is essential for proper lung function. Without adequate surfactant production, the lungs can become stiff and less able to expand and contract, leading to respiratory difficulties..

[Audio] 4. Protecting against infection: Lung surfactants contain a range of proteins and lipids that can help to protect against inhaled pathogens and environmental toxins. These substances can act as a barrier, preventing harmful substances from entering the lungs and causing damage..

[Audio] Next is types of lung surfactants There are two main types of lung surfactants: natural and synthetic. Natural surfactants are derived from animal lung tissue, while synthetic surfactants are produced in the laboratory Synthetic surfactants have been developed as a treatment for RDS in premature infants and have been shown to improve lung function and reduce the risk of complications..

[Audio] Now to conclude that Overall, lung surfactants are critical for maintaining healthy lungs and proper respiratory function. Deficiencies in surfactant production can lead to a range of respiratory problems, including respiratory distress syndrome in premature infants and other lung diseases in adults..