Cell Junctions Section 5 7 Learning Objectives O

Cell Junctions Section 5. 7

Learning Objectives O Compare the structures and functions of anchoring junctions, tight junctions, gap junctions, and plasmodesmata

Cell Junctions O Cell junction = Structure that connects a cell to other cells O Aid in cellular communication O Help cells stick together to make tissues O Prevent the passage of materials O 4 main types O Anchoring junctions O Tight junctions O Gap Junctions O Plasmodesmata

Anchoring Junctions O Found in animal cells O 2 Functions: O Locks cells together O Found in large number in skin & tissues that experience scratching or stretching O Strengthen tissues that contract O Ex. Found in heart muscle O Connect cytoskeleton filaments inside the cell to the ECM on the outside of the cell O Allows messages from the outside environment to be received

Desmosomes Adhering Junctions

Tight Junctions O Found in animal cells O Prevent body fluids from leaking between neighboring cells O Ex. Lining of your stomach is covered in tight junctions to keep stomach acid in your stomach O Found in tissues that line body surfaces or form internal cavities

Gap Junctions O Found in animal cells O Make channels that connect the cytoplasm of neighboring cells O Similar to plasmodesmata O Can open or close in response to a stimulus (aid in communication) O Found in cells that perform coordinated actions

Plasmodesmata O Found in plant cells O Open channels (tubes) that go through the cell walls O Connects the cytoplasm of adjoining cells O Similar to gap junctions in animal cells