Lamellar bodies

From WikiMD's Wellness Encyclopedia

(Redirected from Keratinosomes)

Lamellar bodies are small organelles found in type II pneumocytes in the lungs and in keratinocytes in the skin. They are responsible for the storage and secretion of surfactant, a substance that reduces surface tension in the lungs and prevents the alveoli from collapsing. In the skin, lamellar bodies contribute to the formation of the epidermal barrier, which protects the body from dehydration and external threats.

Structure and Function[edit | edit source]

Lamellar bodies are named for their unique structure, which consists of concentric layers of lipid bilayers. These layers are composed primarily of phospholipids, the most abundant of which is dipalmitoylphosphatidylcholine (DPPC). DPPC is the main component of lung surfactant and is crucial for its function.

In the lungs, lamellar bodies are secreted by type II pneumocytes into the alveolar space, where they unfold into a monolayer that covers the alveolar surface. This surfactant layer reduces surface tension and prevents the alveoli from collapsing during exhalation.

In the skin, lamellar bodies are secreted by keratinocytes into the stratum corneum, the outermost layer of the skin. Here, they contribute to the formation of the epidermal barrier by releasing lipids and proteins that seal the spaces between corneocytes, the dead skin cells that make up the stratum corneum.

Clinical Significance[edit | edit source]

Abnormalities in lamellar body function can lead to several diseases. In the lungs, insufficient surfactant production or secretion can result in respiratory distress syndrome (RDS), a condition that causes severe breathing difficulties. In the skin, defects in lamellar body function can lead to ichthyosis, a group of skin disorders characterized by dry, scaly skin.

Lamellar body count (LBC) is a test used to assess fetal lung maturity. A high LBC indicates that the fetal lungs are producing sufficient surfactant and are likely mature enough for the baby to breathe independently after birth.

See Also[edit | edit source]

References[edit | edit source]


WikiMD
Navigation: Wellness - Encyclopedia - Health topics - Disease Index‏‎ - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes

Search WikiMD

Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD

WikiMD's Wellness Encyclopedia

Let Food Be Thy Medicine
Medicine Thy Food - Hippocrates

Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.

Contributors: Prab R. Tumpati, MD