Intercellular Junctions Flashcards
Intercellular junctions?
links between membranes
Types of junctions between animal cells?
- anchoring junctions
- tight junctions
- gap-junctions
gap-junctions - structure
tunnels (proteins) connectins cytoplasm of adjacent cell
pores lined with proteins that have the ability to open and close
gap-junctions - functions
allow fast passage of ions and small molecules between cells
gap-junctions - examples
- any muscle that needs coordinate movement (heart)
- peristaltic contractions
- pancreas and embryo
tight junctions - structure
ziploc bag example
rows of tightly packed particules
varies depending on : number and patters of strands
tight-junctions - functions
- prevent leakage of extracellular liquids
2. establishing membrane polarity of cell membrane
whre are found the tight junctions that prevent the leakage of extracellular fluids?
found between the cells that line the cavities in mammalian body
What are the tight-junctions that establish polarity of the cell membrane for?
hey prevent the membrane proteins from iffusion throughout the membrane.
thight junctions - examples
- intestinal epithelial cell
- blood-testes barriers
- prevent water loss between skin cells
anchoring junctions - functions
machanically keep cells together/attached
ancoring junctions - structure
plaques on inners surface - intermidiate filaments- transmembrane proteinsconnet plaques - keratin filaments reinforce desmosome in intercellular space
desmosomes?
junctions between 2 cells in anchoring junctions
adheren junctions (hemidesmosomes)
in adherent junctions - junction between a cell and a connective tissue
junction between cell plants
plasmodesmata
