CELL JUNCTION 6
Acell junction can be considered as a structure that is found in atissue of a multicellular organism such as animals. Cell junctionsare mostly found in the epithelial tissues. These cell junctionsmajorly contain proteins, and they offer a connection between theadjacent cells or amongst a cell and the extracellular matrix.Similarly, these cell junctions have the capacity to develop theparacellular barricade of epithelia, and that helps in the control ofthe paracellular passage. Additionally, the plasma membranes of theneighboring cells are separated by extracellular fluids that permittransport of waste and nutrients to and from the bloodstream. In thisparticular concept, five types of junctions were discussedelaborately, and they include gap junction, tight junction, adherencejunctions, hemidesmosomes, and desmosomes(s". Anatomy& Physiology,2017).
Introductionto the Concepts
Theseare types of junctions that are located in the animal cells thatpermit varied ions and molecules to pass through easily without anyobstruction. The junction is very significant as it connects thecytoplasm of cells. Every gap junction comprises of two hemichannelsthat connect across the intercellular space. The following are someof the functions of the gap junction: allows direct transmissionelectrical between the cells, permits chemical transfer between thecells, and allows all molecules smaller than 1,000 Dalton to passthrough(Sun et al., 2016).Additionally, gap junction is imperative in the cardiac muscle sincethe signal to contact is transmitted efficiently via the gap junctionpermitting the heart muscles to contract in tandem. This concept ofgap junction was confusing because in week three the explanation wasvery brief. Lack of elaborate explanation gave me confusion on thedifference between the tight junction and the gap junction since theyare similar (Sunet al., 2016).
Tightjunctions are also known as the zonula accidents are common in areaswhere there are two cells in which their membranes have fusedtogether creating a simulated impermeable obstacle to liquid. Thesejunctions are formed by occluding and claudin proteins which arejoining the cytoskeletons of the nearby cells. Similarly, tightjunctions have the following purposes: bind cells to become one, andblock the movement of ions and molecules (Sunet al., 2016).Challenges that I was finding on tight junctions is where they arefound. Having a clear understanding of where the junctions arelocated is imperative as that helps to grasp the concept adequately. Similarly, I was getting difficulty on how these junctions areformed, but after the research a got to know how tight junctions areformed (Sunet al., 2016).
Theadherence junction is also known as the zonula adherens, and they areprotein complex that is located in the epithelial tissues at thecell-cell junctions. The adherences junctions can look differently,for example, they can look like bands enclosing the cell (zonulaadherence) or sometimes as spots of connection to the extracellularmatrix(Weng & Wieschaus, 2016).These adherence junctions comprised of 3 proteins namely: Catherins,Becatenin, and Acetanin. Similarly, the adherence junction conservesthe physical integrity of the epithelium. These junctions are knownto form adhesion belt between the epithelial cells. In week three,much information was not given relating to the adherence junction. Iwas being confused on how they appear. The appearance of thesejunctions is very significant as it can help to distinguish them fromother junctions (Weng& Wieschaus, 2016).
Thehemidesmosomes are structures that are in the form of rivet-likearrangements that assist in connecting the basal membrane (basallamina) of the ECM. For instance, in the skin, keratin in-betweenfilaments can connect to a plektin plaque. Similarly, the plektinplaque can also connect to the integrins that also fuse to componentsof the basement membrane such as the laminin. The challenge that Iwas facing about the hemidesmosomes was the difference between it andthe desmosomes. These cell junctions are somehow similar, and thatgave me a hard time to differentiate them explicitly(Janssen et al., 2016).
Thedesmosomes are also called the macula adherens, and they are known toform a cell arrangement that is meant for cell-to-cell adhesion.Desmosomes is a specialized category of the junctional complex whichis restricted spots-like adhesions that are casually arranged on thehorizontal sides of the plasma membrane(Hardin, 2016).Desmosomes are important since they help in resisting shearing forceand are found in stratified and straightforward squamous epithelium.The challenge that I experienced with the desmosomes is about thefunctions and how important they are in the body. Additionally,differentiating it with hemidesmosomes was a challenge until I gotdown and conducted this research that helped to get some featuresthat helped me to distinguish them (Hardin,2016).
DeeperUnderstanding of the Content
Theinformation derived from the sources has enhanced my understanding asfar as cell junction is concerned. Additionally, the concept of thesesources are well presented and it simple to understand. In thesources, the authors used diagrams to explain further and that helpin digesting the context adequately. The sources have improved myunderstanding of the concept because I can tell precisely thedifference between different cell junctions. The sources alsoexplained how different types of cell junctions are formed and theirlocations. Some of the information derived from the sources include:defining of various kinds of cell junctions, a clear understanding ofthe functions and structures of the five types of cell junction,identifying different sites of their distribution and listing thecomponents of the junctional complex (Hardin,2016).
Reflectionon the Usefulness and Quality of the Sources
Allthe sources that were used for this research were useful in thecontext of what have been so far learned. Before conducting theresearch, my understanding of the cell junction was not as broad asnow. That is because I have done an in-depth research and I was ableto obtain different information from varied sources. The quality ofthe sources used was very high as they provided finer details of thecell junctions which we did not learn in the class. Similarly, thesesources are very useful as they have managed to broaden myunderstanding on the cell junction. I can improve on my conceptunderstanding through extensive research by reading articles thathave been published by other authors.
Acell junction can be considered as a structure that is found in atissue of a multicellular organism such as animals. Similarly, thereare five types of cell junctions: gap junction, tight junction,adherence junctions, hemidesmosomes, and desmosomes. Students must beencouraged to conduct research as that will help them understandconcepts that have been taught in class
"CellJunctions". Anatomy& Physiology.N.p., 2017. Web. 6 Apr. 2017.
Janssen,D. A. W., Jansen, C. J. F., Hafmans, T. G., Verhaegh, G. W.,Hoenderop, J. G., Heesakkers, J. P. F. A., & Schalken, J. A.(2016). TRPV4 channels in the human urogenital tract play a role incell junction formation and epithelial barrier. ActaPhysiologica,218(1),38-48.
Sun,B., Chen, Z., Gu, J., Tse, G., Jiang, J., Huang, F., & Zhao, C.(2016). Tight junction proteins and gap junction proteins playimportant roles in high fat dietary atherosclerosis pathogenesis.INTERNATIONALJOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY,9(8),7969-7976. http://www.ijcep.com/files/ijcep0031355.pdf
Weng,M., & Wieschaus, E. (2016). Myosin-dependent remodeling ofadherens junctions protects junctions from Snail-dependentdisassembly. JCell Biol,212(2),219-229.http://jcb.rupress.org/content/jcb/212/2/219.full.pdf
Hardin,J. (2016). Regulating cell–cell junctions from A to Z. JCell Biol,213(2),151-153.
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