Chapter 5_ Histology (1).pdf - The Human Tissues Histology...

This preview shows page 1 - 16 out of 96 pages.

The Human TissuesHistologyChapter 5Josephine Bou Dagher
CytologyThe study of cellsThe cellThis Photoby Unknown Author is licensed underCC BY-NC-ND
3CELLSCells are the simplest unit of life.All organisms are composed of cells.Cells are derived from other cells.All physiological processes based on cellactivity.
4Cell ComponentsPlasma (cell) membraneSurrounds cell, defines boundariesMade of proteins and lipidsSelectively permeableCytoplasmOrganellesCytoskeletonInclusions (stored or foreign particles)Cytosol (intracellular fluid, ICF)Extracellular fluid (ECF)Fluid outside of cells includes tissue (interstitial) fluid
HistologyThe study of TissuesThe Tissue
What are Tissues?
6
7Tissue ComponentsEXTRACELLULAR MATRIX (ECM)Fibrous ProteinsCollagenousReticularElasticAlso Known As:-Interstitial fluid-Extracellular Fluid (ECF)-Tissue Fluid-Tissue GelGround Substance(Liquid, Solid, or gel)CELLSTissue=Cells + Extracellular Matrix (ECM)Functions:-Where cells gain: water,gases, minerals, nutrients-Where cells release :wastes, hormones, andother products-Protective: absorbs shock.
8CellsSquamousCuboidalColumnarPolygonalStellateSpheroidalDiscoidalFusiformFibrous
9Cells are joined by JUNCTIONSFunctions:Bind cells togetherCell-cell communicationForm permeability layerLocations:Lateral SurfaceBasal SurfaceTypes:Tight JunctionsGap JunctionsDesmosomesHemidesmosomes
10JunctionsTIGHT JUNCTIONS:Tightly join epithelial cellsnear apical surfaceSeal space between cellsto prevent leakage orbacterial invasionGAP JUNCTIONSCommunicating junction6 transmembrane proteinsforminga channelSolutes and water passthrough cell-to-cellCommon in smoothmuscle, cardiac muscle,lens, cornea, embryonictissues, and tissueslacking blood vessels.
11JunctionsDESOMOSOMES:Hold cells togetherResist mechanical stressNot continuous like tightjunctionsCommon in epithelialcellsHEMI-DESOMOSOMES:Half-desmosomeBind basal cells ofepithelial tissue tounderlying fibers(basement membrane)Prevent epithelium frompeeling away.
12Four types of TissuesEpithelialEpidermisInner Lining of digestivetractMuscularSkeletal MusclesCardiac Muscles (Heart)Smooth Muscles (Viscera)NervousBrainSpinal CordNervesConnectiveTendons and LigamentsCartilage and BoneBlood“covers”“contracts”“communicates”“connects”
Nervous Tissue
14Nervous TissueFUNCTIONSenses stimuliRapidly transmits informationLOCATIONBrainSpinal CordNervesCELLSNeuronsGlial cells
15Nervous Tissue: NeuronsFUNCTIONCarry signals by conductingelectrical impulsesCell body = Soma = NeurosomaWhere nucleus and organelles arepresentAxonCarries electrical impulsesawayform the cell bodyOne per cellDendriteReceives signals1 or Many per cell

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 96 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
Wenzel
Tags
Collagen

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture