Which of the following components of the pulmonary surfactant mainly contribute to its physiological function?
Correct Answer: Lipid and protein
Description: Pulmonary surfactant, composed of lecithin and myelin, is secreted on a continuous basis by type II alveolar cells and Clara cells beginning at approximately week 20 of gestation. Pulmonary surfactant has both a lipid (approximately 90% of total) and a protein (approximately 10% of total) component. About half of the lipids are dipalmitoylphosphatidylcholine. The remaining lipids include phosphatidylglycerol, which modulates the fluidity of the surfactant as well as cholesterol and other lipids. About half of the proteins are apoproteins, which have both hydrophobic and hydrophilic poions; the other half is composed of proteins normally found in blood plasma. These lipids and proteins all have the capability of interacting with hydrophilic or hydrophobic environments and it is this quality that leads to their specialized function in the lung. Ref: Huang H.J. (2012). Chapter 17. The Respiratory System. In L.W. Janson, M.E. Tischler (Eds), The Big Picture: Medical Biochemistry.
Category:
Physiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now