Lamellar bodies: Difference between revisions

Latest revision as of 05:44, 16 February 2025

Lamellar Bodies[edit]

Micrograph of lamellar bodies in lung tissue

Lamellar bodies are specialized organelles found in certain cell types, most notably in type II alveolar cells of the lung and in keratinocytes of the skin. These organelles play a crucial role in the production and secretion of surfactant in the lungs and in the formation of the skin's protective barrier.

Structure[edit]

Lamellar bodies are characterized by their unique, concentric, lamellar structure. They are membrane-bound organelles that contain tightly packed layers of lipids and proteins. In the lungs, these lipids are primarily composed of phospholipids, which are essential for reducing surface tension in the alveoli.

Function[edit]

In the Lungs[edit]

In the pulmonary system, lamellar bodies are responsible for storing and secreting pulmonary surfactant. Surfactant is a complex mixture of lipids and proteins that reduces surface tension in the alveoli, preventing their collapse during exhalation and ensuring efficient gas exchange. The secretion of surfactant from lamellar bodies is a critical process for normal respiratory function, particularly in newborns.

In the Skin[edit]

In the epidermis, lamellar bodies are involved in the formation of the skin's barrier function. They secrete lipids and enzymes that contribute to the formation of the stratum corneum, the outermost layer of the skin. This barrier is essential for preventing water loss and protecting against environmental insults.

Clinical Significance[edit]

Disorders in lamellar body function can lead to significant clinical conditions. In the lungs, insufficient surfactant production can result in respiratory distress syndrome (RDS), particularly in premature infants. In the skin, defects in lamellar body secretion can contribute to conditions such as ichthyosis and other barrier-related skin disorders.

Related Pages[edit]

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-'''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.
+== Lamellar Bodies ==
-== Structure and Function ==
+[[File:Journal.pone.0031641.g003.png|thumb|right|Micrograph of lamellar bodies in lung tissue]]
-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.
+'''Lamellar bodies''' are specialized organelles found in certain cell types, most notably in [[type II alveolar cells]] of the [[lung]] and in [[keratinocytes]] of the [[skin]]. These organelles play a crucial role in the production and secretion of [[surfactant]] in the lungs and in the formation of the skin's protective barrier.
-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.
+== Structure ==
+Lamellar bodies are characterized by their unique, concentric, lamellar structure. They are membrane-bound organelles that contain tightly packed layers of [[lipids]] and [[proteins]]. In the lungs, these lipids are primarily composed of [[phospholipids]], which are essential for reducing surface tension in the alveoli.
-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.
+== Function ==
-== Clinical Significance ==
+=== In the Lungs ===
+In the [[pulmonary system]], lamellar bodies are responsible for storing and secreting pulmonary surfactant. Surfactant is a complex mixture of lipids and proteins that reduces surface tension in the alveoli, preventing their collapse during exhalation and ensuring efficient gas exchange. The secretion of surfactant from lamellar bodies is a critical process for normal respiratory function, particularly in newborns.
-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.
+=== In the Skin ===
+In the [[epidermis]], lamellar bodies are involved in the formation of the skin's barrier function. They secrete lipids and enzymes that contribute to the formation of the stratum corneum, the outermost layer of the skin. This barrier is essential for preventing water loss and protecting against environmental insults.
-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.
+== Clinical Significance ==
+Disorders in lamellar body function can lead to significant clinical conditions. In the lungs, insufficient surfactant production can result in [[respiratory distress syndrome]] (RDS), particularly in premature infants. In the skin, defects in lamellar body secretion can contribute to conditions such as [[ichthyosis]] and other barrier-related skin disorders.
-== See Also ==
+== Related Pages ==
-* [[Type II pneumocyte]]
-* [[Keratinocyte]]
 * [[Surfactant]]
+* [[Type II alveolar cells]]
 * [[Respiratory distress syndrome]]
-* [[Ichthyosis]]
+* [[Keratinocytes]]
+* [[Stratum corneum]]
-== References ==
-{{reflist}}
 [[Category:Cell biology]]
 [[Category:Pulmonology]]
 [[Category:Dermatology]]
-{{Cell-biology-stub}}
-{{Pulmonology-stub}}
-{{Dermatology-stub}}