Definition

1. Noun:
   • A type of cell that forms the epithelium: An epithelial cell is one of the tightly packed cells that make up epithelial tissue, which lines the surfaces and cavities of the body's organs and structures.

Usage

• Epithelial cells are the primary building blocks of epithelial tissue.
• They are characterized by close cell-to-cell adhesion and polarity.
• These cells can be classified by shape (e.g., squamous, cuboidal, columnar) and layering (e.g., simple, stratified).

Examples

• Noun:
  • The skin's outer layer is composed of stratified squamous epithelial cells.
  • Damage to the intestinal lining involves the loss of epithelial cells.
  • A biopsy confirmed the presence of abnormal epithelial cells.

Advanced Usage

• "Epithelial cell turnover": The continuous process of cell regeneration and shedding in an epithelium.

  • The rapid epithelial cell turnover in the gut lining helps maintain a barrier against pathogens.

• "Epithelial cell polarity": The structural and functional differences between the apical (top) and basolateral (bottom/side) surfaces of the cell.

  • Epithelial cell polarity is essential for directional absorption and secretion.

Variants and Related Words

• Epithelium (n): The tissue formed by a sheet of epithelial cells.

  • The cornea is covered by a transparent epithelium.

• Epithelial (adj): Of or relating to epithelium or epithelial cells.

  • The biopsy showed epithelial tissue.

• Non-epithelial cell (n): A cell that is not part of an epithelium, such as a neuron or muscle cell.

Synonyms

• Epitheliocyte (n): A less common synonym for an epithelial cell.

Related Phrases and Terms

• Epithelial-mesenchymal transition (EMT): A process where epithelial cells lose their characteristics and gain migratory properties.

  • Epithelial-mesenchymal transition is a key step in embryonic development and cancer metastasis.

• Epithelial barrier: The protective layer formed by epithelial cells and their junctions.

  • The epithelial barrier in the lungs prevents the entry of dust and microbes.

Noun

1. one of the closely packed cells forming the epithelium