Tight Juctions, Gap Tight Juctions, Gap Junctions and Animal Junctions and Animal Extracellular MatrixExtracellular Matrix

By: Christina SzabadosBy: Christina Szabados

Tight JunctionsTight Junctions

Occur when the membranes of two cells move close to each other in order to prevent molecules from passing between cells. This helps in holding cells together.

Fence Function Fence Function

This function ensures that molecules This function ensures that molecules in the apical outer membrane will not in the apical outer membrane will not mix with the those in the lateral mix with the those in the lateral membrane of the cell, by blocking the membrane of the cell, by blocking the movement of proteins in the movement of proteins in the membranes. membranes.

Barrier Function Barrier Function

•Does not allow the passage of molecules Does not allow the passage of molecules from one cell to another.from one cell to another.

•This forces material to go through the cell, This forces material to go through the cell, so the transportation of materials is so the transportation of materials is regulated within the cell. regulated within the cell.

•Molecules regulated can include ions, Molecules regulated can include ions, water, macromolecules, and cancer cells.water, macromolecules, and cancer cells.

Tight Junctions Also…Tight Junctions Also…•are prevalent in the cells in the skin, are prevalent in the cells in the skin, gastrointestinal track, respiration, actin, gastrointestinal track, respiration, actin, cytoplasm, and ATPcytoplasm, and ATP

•are responsible for the blood brain barrier, are responsible for the blood brain barrier, which protests the nervous system. which protests the nervous system.

•make and maintain the cell polarity of the make and maintain the cell polarity of the cell, by regulating the structure of the cell’s cell, by regulating the structure of the cell’s lining during polarization. lining during polarization.

Diseases From Tight Diseases From Tight Junction MalfunctionsJunction Malfunctions

•Disorders in tight junctions can Disorders in tight junctions can cause jaundice, diarrhea, and edemacause jaundice, diarrhea, and edema

•In order to regulate molecules In order to regulate molecules passing through the cell, tight passing through the cell, tight junctions force molecules such as junctions force molecules such as cancer cells to pass through a cell. If cancer cells to pass through a cell. If there is a problem in this process there is a problem in this process cancer can occur. cancer can occur.

Gap JunctionsGap Junctions•Are a passageways between two Are a passageways between two cell membranes, that connect the cell membranes, that connect the cytoplams of the cells. cytoplams of the cells.

•They are formed by They are formed by which come together in neighboring which come together in neighboring cells to form passageways between cells to form passageways between them.them.

•The opening and closing of The opening and closing of connexins can be controlled within connexins can be controlled within the cellthe cell

Connexins,Connexins,

Gap Junctions can be found in the cardiac muscle of the heart, Gap Junctions can be found in the cardiac muscle of the heart, neurons in the brain, and neurons in the retina. neurons in the brain, and neurons in the retina.

They also insure the molecules passing between cells do not They also insure the molecules passing between cells do not leak into the intercellular space. leak into the intercellular space.

Diseases from Gap Diseases from Gap JunctionsJunctions

Those who are Those who are predisposed to having an predisposed to having an arrhythmia and have a arrhythmia and have a heart attack often have a heart attack often have a defect in the gap junctions defect in the gap junctions of their heart. This defect of their heart. This defect can be an alteration in the can be an alteration in the gap junction or a problem gap junction or a problem with the connexins. with the connexins.

Animal Extracelular Animal Extracelular MatrixMatrix

The EMC is connective tissue made from The EMC is connective tissue made from proteins and polysaccharides. This tissue has proteins and polysaccharides. This tissue has elastin fibers to create elasticity in cells, so elastin fibers to create elasticity in cells, so structures such as the lungs can be both structures such as the lungs can be both flexible and strong. flexible and strong.

Functions:Functions:-Gives animal cells diverse structural support such -Gives animal cells diverse structural support such as in the bones, cartilage, and the eye’s cornea. as in the bones, cartilage, and the eye’s cornea. The differences in necessary functions requires a The differences in necessary functions requires a diversity of forms in the EMC which is achieved diversity of forms in the EMC which is achieved through different amounts of macromolecules in the through different amounts of macromolecules in the tissue. tissue. -segregates tissue-segregates tissue-regulates the communication within cells-regulates the communication within cells-aides in growth, wound healing, and fibrosis-aides in growth, wound healing, and fibrosis

Extracellular Matrix DiseasesExtracellular Matrix Diseases

•Cells are extremely dependent on the EMC for Cells are extremely dependent on the EMC for survival.survival.•Cellular diseases can result from the build up of Cellular diseases can result from the build up of toxins in the extracellular matrix, therefore it is toxins in the extracellular matrix, therefore it is prevalent in areas which are heavily polluted. prevalent in areas which are heavily polluted. •The abnormal transformation of cancer cells, The abnormal transformation of cancer cells, because they often lack fibronectin in the EMC, because they often lack fibronectin in the EMC, causes less adhesion, this can result in the cancer causes less adhesion, this can result in the cancer cell breaking off from the tumor and spreading to cell breaking off from the tumor and spreading to other parts of the body. other parts of the body.

SourcesSources::www.wentweb.com/images/brain_001.jpgwww.biologyreference.com/Ce-Co/Cell-Junctions.htwww.biologyreference.com/Ce-Co/Cell-Junctions.ht

resources.metapress.com/pdf-preview.axd?code=blresources.metapress.com/pdf-preview.axd?code=bl

en.wikipedia.org/wiki/Tight_junctionen.wikipedia.org/wiki/Tight_junction

kwjersey.com/wp-content/uploads/take-down-fencekwjersey.com/wp-content/uploads/take-down-fence

en.wikipedia.org/wiki/Gap_junctionen.wikipedia.org/wiki/Gap_junction

www.springerlink.com/content/blvd0k5ptlvbtwlt/www.springerlink.com/content/blvd0k5ptlvbtwlt/

circres.ahajournals.org/cgi/content/full/86/12/1

/cardiovascres.oxfordjournals.org/cgi/content/ab/cardiovascres.oxfordjournals.org/cgi/content/ab

www.integrativedentalmedicine.com/TABS/ecm.jpg www.integrativedentalmedicine.com/TABS/ecm.jpg

www.offthemarkcartoons.com/cartoons/1996-03-29.gifwww.offthemarkcartoons.com/cartoons/1996-03-29.gif