Intercellular junctions_2
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Transcript of Intercellular junctions_2
BY: MADIHA SHAMS BDS (1 S T YEAR)
GROUP: A DOW UNIVERSITY OF HEALTH SCIENCES
INTERCELLULAR JUNCTIONS
JUNCTIONS BETWEEN CELLS
When Cells come into contact with each other, various junctional arrangements may form. They are classified as follow:
TIGHT (Occluding) JUNCTIONS
•Tight junctions, or Zonula occludens arethe closely associatedareas of two cells whose membranes join together forminga virtually impermeable barrier to fluid. It is a type ofjunctional complex present only in vertebrates.
• Tight junctions, combine well with membranes of adjacent cells by anInterlocking Systemof occluding ridgesmuch like the teeth ofa zipper.
JUNCTION COMPLEX
Tight Junction + Adhesive Junction
ANCHORING (Adhering) JUNCTIONS
ZONULA ADHERENS
Zone of belt-desmosome or Adherens Junction
MACULA ADHERENS-DESMOSOMES
In Cardiac Muscle In Epithelial Tissue
Hemidesmosomes
(Half-Desmosome) : They connect intermediate Filament to Basal and separate plasma membraneof cell from Basal Lamina.
FOCAL ADHESION
• Adherens junctions calledFOCAL ADHESION can join a cell to the ECM, primarily through fibronectinreceptors.
GAP (Communicating) JUNCTIONS
Cytoplasmic bridgebetween cells for passing chemical &electrical signals. They are frequentlyfound in epithelial Cells.Mostly in heart &nerves, but can be found in liver, pancreas, ovary.