Modification of Plasma Membrane | Class 11 & NEET Free Notes

Modification of Plasma Membrane

In this article we will discuss about:- Microvilli, Inter digitations, Tight junction, Gap junction, Desmosomes and Plasmodesmata

What is Modification of Plasma Membrane?

  • Plasma membrane shows some specialized structures
  • To perform some additional functions plasma membrane shows some changes
  1. Free Surface Modification
  2. Junctional Complex

[ Must Read: Fluid Mosaic Model of Plasma Membrane ]

  1. Free Surface Modification


  • Minute finger like projections arising from surface of certain cells
  • Single cell contains more than 3000 microvilli
  • Found in epithelial cells of intestine, kidney tubules, gall bladder and hepatic cells
  • Function: increase the surface area for absorption
  1. Junctional Complex

Inter digitations

  • Plasma membrane of adjacent cells project into cytoplasm as finger-like projections
  • Found in lymph nodes and lymphoid tissues
  • Function: increase surface area for exchange of substance between the cells

Tight junction

  • Plasma membrane of adjacent cells fuses by extrinsic proteins
  • Found in brain cells, gall bladder and intestinal cells
  • Function: adhesion

Gap junction

  • Gap junction is channel through two cell membranes across the intercellular space between two adjacent cells
  • Found in cardiac muscles
  • Function: conduct electrical signals & passage of ions, sugar, vitamin and metabolites


  • Desmosomes are thickened areas of plasma membrane of two adjacent cells
  • Found in cardiac muscle and skin cells
  • Function: help to glue the cells together


  • Cytoplasm of adjacent cell connected with cytoplasmic strands
  • Found in plant cells
  • Function: exchange of materials between two cells

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