Final Answer:
The lipid substance that helps prevent the alveoli from collapsing is Surfactant. Thus the correct answer is A) surfactant.
Step-by-step explanation:
Surfactant is a lipid-based substance that lines the inner surfaces of the alveoli in the lungs. Its primary function is to reduce surface tension, preventing the alveoli from collapsing during exhalation. This substance is crucial for maintaining the structural integrity of the alveoli and facilitating efficient gas exchange in the lungs. Without surfactant, the alveoli would collapse, making it challenging for the lungs to effectively exchange oxygen and carbon dioxide during breathing.
Alveoli are tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide occurs. The surface tension within these air sacs can cause them to collapse. Surfactant acts as a kind of detergent, reducing this tension and allowing the alveoli to remain open even after exhaling. This process ensures that the lungs remain functional, enabling efficient gas exchange with each breath. Understanding the role of surfactant is fundamental in appreciating the mechanics of breathing and how the body maintains respiratory function.
The absence or deficiency of surfactant can lead to respiratory distress syndrome, particularly in premature infants whose lungs have not yet produced enough surfactant. Hence, recognizing the significance of this lipid substance in the lungs underscores its critical role in sustaining proper respiratory function and preventing complications associated with collapsed alveoli. Thus the correct answer is A) surfactant.