What is the Difference Between Myoepithelial and Lamina Epithelial Cells

The main difference between myoepithelial and lamina epithelial cells is that myoepithelial cells occur beneath the luminal epithelial cells in the glandular tissue, whereas lamina epithelial cells are the epithelial cells that overlay the basal lamina.   

Myoepithelial and lamina epithelial cells are two types of epithelial cells that occur in the body. They appear as layers on the extracellular matrix called basal lamina.   

Key Areas Covered

1. What are Myoepithelial Cells
– Definition, Structure, Function
2. What are Lamina Epithelial Cells
– Definition, Structure, Function
3. Similarities Between Myoepithelial and Lamina Epithelial Cells
– Outline of Common Features
4. Difference Between Myoepithelial and Lamina Epithelial Cells
– Comparison of Key Differences

Key Terms

Lamina Epithelial Cells, Myoepithelial Cells

What are Myoepithelial Cells

Myoepithelial cells are epithelial cells that occur in the glandular epithelium. They appear as a thin layer above the basal lamina beneath the luminal epithelial cells. However, these cells are similar to smooth muscle cells and contain actin. Also, they contain cytokeratin 5/6 and other high molecular weight cytokeratins, p63, and caldesmon. Their function is to contract, expelling the secretions of the exocrine glands. Moreover, myoepithelial cells occur in the salivary glands, sweat glands, lacrimal glands, and mammary glands. Besides, myoepithelial cells also appear on the basement membrane of the epithelial tissue and serve as epithelial progenitor cells. In wound healing, myoepithelial cells continuously proliferate.

Figure 1: Mammary Gland

Furthermore, on the myoepithelial cells, luminal epithelial cells occur in the glandular structures.

What are Lamina Epithelial Cells

The laminal epithelial cells are any animal cells covering the surfaces or lining a cavity and performing secretory, transporting, or regulatory functions. Apical basal polarity is one of the significant characteristics of the epithelium. This means the basal surface of the epithelial cells is attached to the basal lamina, and the apical surface of the cells faces the lumen. Lamina epithelial cells are arranged together to create a continuous sheet by forming desmosomes and tight junctions. The basal lamina is attached to a connective tissue layer called the reticular lamina. Also, there is no blood or nerve supply between these epithelial cells (avascular). Besides, epithelial cells exhibit a high regenerative capacity as well.

Figure 2: Epithelial Tissue

Moreover, three types of cells occur in the epithelium. They are squamous, cuboidal, and columnar epithelium. The squamous epithelium comprises flat and scale-like cells. The cuboidal cells are block-like, and the columnar cells are tall. These three cell types are arranged into a single or several cell layers. When an epithelium comprises a single layer of epithelial cells, it is called the simple epithelium. On the other hand, several epithelial cell layers produce a stratified epithelium.

Similarities Between Myoepithelial and Lamina Epithelial Cells

• Myoepithelial and lamina epithelial cells are two types of epithelial cells in the body.
• Both contain basal lamina.

Difference Between Myoepithelial and Lamina Epithelial Cells

Definition

Myoepithelial cells refer to the monolayer of specialized pavement-like cells that often line the body’s serous cavities and vital organs, while lamina epithelial cells refer to a type of cells that line the outer surface of the organs and blood vessels and inner surface cavities of the many internal organs.

Structure

Myoepithelial cells are thin and spindle-shaped and ultrastructurally possess several Cytoplasmic processes that extend between and over the acinar and ductal-lining cells, while lamina epithelial cells are the thin, continuous, protective layer of compactly packed cells with a little intercellular matrix.

Location

Myoepithelial cells occur in multiple glandular organs such as the lacrimal, salivary, harderian, sweat, prostate, and mammary glands while lamina epithelial cells line the internal organs and body cavities and form the outer layer of the skin.

Function

Myoepithelial cells regulate the flow of fluid and control the entry and exit of nutrients, electrolytes, and other growth factors. At the same time, diffusion, filtration, secretion, selective absorption, germination, and transcellular transport are the functions of the lamina epithelial cells.

Conclusion

In brief, myoepithelial and lamina epithelial cells are two types of epithelial cells in the body. Mypepthelial cells are pavement-like cells in the body’s serous cavities, such as lacrimal, salivary, harderian, sweat, prostate, and mammary glands. They possess several cytoplasmic processes. Also, they regulate the flow of fluids, controlling the entry and exit of nutrients, electrolytes, and growth factors. In comparison, lamina epithelial cells are a type of cells that line the cavities of the internal organs. Also, they are thin and continuous protective layers, controlling diffusion, secretion, filtration, selective absorption, and germination. Therefore, the main difference between myoepithelial and lamina epithelial cells is their structure and function.  

References:

1. Gudjonsson T, Adriance MC, Sternlicht MD, Petersen OW, Bissell MJ. Myoepithelial cells: their origin and function in breast morphogenesis and neoplasia. J Mammary Gland Biol Neoplasia. 2005 Jul;10(3):261-72. doi: 10.1007/s10911-005-9586-4. PMID: 16807805; PMCID: PMC2798159.
2. Epithelial tissue. Epithelial Tissue | SEER Training. (n.d.). 

Image Courtesy:

1. “Normal breast histology” By Mikael Häggström – Own work (CC-BY 4.0) via Commons Wikimedia
2. “Illu epithelium” By US Government – Own Work (Public Domain) via Commons Wikimedia