2. tissue level of organization

Tissue level of organization
Classification of tissues, structure, location and functions of epithelial,
muscular and nervous and connective tissues.

1. Tissue Level of Organization
By
Yogeshwary M. Bhongade
Assistant Professor
KamlaNeharuCollege of Pharmacy, Butibori, Nagpur

2. Tissues
•Tissuesaregroupsofsimilarcellsthathaveacommonfunction.
•Thefourbasictissuetypesareepithelial,muscle,connective,and
nervoustissue.Eachtissuetypehasacharacteristicroleinthebody:
Tissue
Epithelial Tissue
Covers the body surface
and lines body cavities
Connective Tissue
Supports and protects body
organs.
Muscular Tissue
Provides movement.
Nervous Tissue
Provides a means of rapid
internal communication by
transmitting electrical
impulses

3. Epithelial Tissue
•It is made up of tightly opposed cells
•They form the covering or lining to the free surface of the body
•Rest on basement membrane
•Seperate epithelial tissues from other tissues
Epithelial
Tissue
Membranous
Epithelium
Glandular tissues

4. Functions of the Epithelium
•Epithelia tissue forms boundaries between different environments, and nearly all
substances must pass through the epithelium. In its role as an interface tissue,
epithelium accomplishes many functions, including:
•Coversthe body surface and linesbody cavities (Pericardial, Peritonial, Plural
Cavitiesand Cardiovasculat System also tined by epithelial tissues. Body tubes are
lined by epithelial tissues)
•Protectionfor the underlying tissues from radiation, desiccation, toxins, and
physical trauma.
•Absorptionof substances in the digestive tract lining with distinct modifications.
•Regulation and excretion of chemicalsbetween the underlying tissues and the
body cavity.
•The secretion of hormonesinto the blood vascular system. The secretion of
sweat, mucus, enzymes, and other products that are delivered by ducts come from
the glandular epithelium.
•The detection of sensation.

5. Characteristics of Epithelial Layers
•Epithelial tissue is composed of cells laid out in sheets with strong cell-to-
cell attachments.
•These protein connections hold the cells together to form a tightly
connected layer that is avascular but innervated in nature.
•The epithelial cells are nourished by substances diffusing from blood
vessels in the underlying connective tissue.
•One side of the epithelial cell is oriented towards the surface of the tissue,
body cavity, or external environment and the other surface is joined to a
basement membrane.
•The basement layer is non-cellular in nature and helps to cement the
epithelial tissue to the underlying structures.

6. Epithelial Tissue
•Epithelialtissuesareidentifiedbyboththenumberoflayersandthe
shapeofthecellsintheupperlayers.
•Thereareeightbasictypesofepithelium:sixofthemareidentified
basedonboththenumberofcellsandtheirshape;twoofthemare
namedbythetypeofcell(squamous)foundinthem.
•Epithelialtissueisclassifiedbasedonthenumberofcells,theshapeof
thosecells,andthetypesofthosecells.

7. Types Of Epithelial Tissues
Membranous
Epithelium
Shape
Squamous Cuboial Columnar
Layers
Simple
Epithelium
Simple
Squamous
Simple Cuboial
Simple
Columnar
Stratified
Epithelium
Stratified
Squamous
Stratified
Cuboial
Stratified
Columnar
Psudostratifies
Epithelium

8. Types of Simple Epithelial Tissue
1.Asimplesquamousepithelium-
•Itisasinglelayerofflatcellsincontactwiththebasallamina(oneof
thetwolayersofthebasementmembrane)oftheepithelium.
•Thistypeofepitheliumisoftenpermeableandoccurswheresmall
moleculesneedtopassquicklythroughmembranesviafiltrationor
diffusion.
•Flat,nucleouslocatedneartheuppersurfacegivesthesecells
appearanceoffriedegg.
•FoundinCVS,RespiratorySystem,Kidney(Nephron)

9. 2. Simple cuboidal epithelium
•It consists of a single layer cells that are as tall as they are wide. The
important functions of the simple cuboidal epithelium are secretion
and absorption.
•This epithelial type is found in the small collecting ducts of the
kidneys, pancreas, and salivary glands, surface of ovaries.
•They are cube or hexagone shape with central, round nucleus.
•These cells produces secretions (Secretions) or absorb substances
(digestive fluid)

10. 3.Simplecolumnarepithelium-
•Itconsistofasinglelayerofcellsthataretallerthantheyarewide.
•Thistypeofepithelialinesthesmallintestinewhereitabsorbsnutrients
fromthelumenoftheintestine.
•Simplecolumnarepitheliaarealsolocatedinthestomachwhereit
secretesacid,digestiveenzymesandmucous.
•Tallwithanovalnucleousnearthebasementmembrane.

11. Types of Stratified Epithelial Tissue
1.Astratifiedsquamousepithelium-
•Itconsistsofsquamous(flattened)epithelialcellsarrangedinlayers
uponabasalmembrane.
•Onlyonelayerisincontactwiththebasementmembrane;theother
layersadheretooneanothertomaintainstructuralintegrity.
•Inthedeeperlayers,thecellsmaybecolumnarorcuboidal.
•FoundinOralCavity,Vaginaandoesophagous.

12. 2.StratifiedcuboidalepithelialTissue
•Itisararetypeofepithelialtissuecomposedofcuboidallyshaped
cellsarrangedinmultiplelayers.
•Theyprotectareassuchasductsofsweatglands,mammaryglands,
andsalivaryglands.

13. 3. Stratified Columnar epithelial Tissue
•Stratified columnar epithelium is a rare type of epithelial tissue
composed of column-shaped cells arranged in multiple layers.
•It is found in the conjunctiva, pharynx, anus, and male urethra.

14. Transitional epithelium
•Transitionalepitheliumisatypeofstratifiedepithelium.
•Thistissueconsistsofmultiplelayersofepithelialcellswhichcan
contractandexpandinordertoadapttothedegreeofdistension
needed.
•Transitionalepitheliumlinestheorgansoftheurinarysystemandis
knownhereasurothelium.

15. Glandular tissues
•Theglandulartissueareamixtureofbothendocrine(ductless,hormones
aresecretedintotheblood)andexocrine(haveducts,hormonesare
secretedontosurfaces)glands.
•Theexocrineglandsarecoveredintherespectivetopics.Forexample
sweatglandsarecoveredinthesectiononskin.
Glandular
tissues
UnicellularMulticellular
Endocrine
Gland
Exocrine
Gland

16. Connective tissue
•Connectivetissueisthetissuethatconnects,separatesandsupportsall
othertypesoftissuesinthebody.
•Likealltissuetypes,itconsistsofcellssurroundedbyacompartment
offluidcalledtheextracellularmatrix(ECM).
•Connectivetissue,groupoftissuesinthebodythatmaintaintheform
ofthebodyanditsorgansandprovidecohesionandinternalsupport.
•Theconnectivetissuesincludeseveraltypesoffibroustissuethatvary
onlyintheirdensityandcellularity,aswellasthemorespecialized
andrecognizablevariants—bone,ligaments,tendons,cartilage,and
adipose(fat)tissue.

17. Functions of Connective Tissue
•Bind togather, support and strenthen body tissue
•Protect and insulate internal organ.
•Transport.
•Store energy in addipose or fat tissue
•Immune response

18. Types of connective tissue
Connective
tissue
Cell
Ground
Substances
Fluid

19. Cells
Connective
Tissue
FibroblastMacrophagesPlasma cellsMast cellAdipocytesLeukocytes

20. Ground Substances
•Present between cell and fibre
•It is in the form of fluid, semifluid or gelateneous or calcified
•Support cell and bind them togather
•Store wathe and organic substances given below.
Connective
Tissue
Polysachharides
Hyaluronic Acid
Chondroitin
Sulphate
Dermatan
Sulphate
Keratin Sulphate
Proteins
Adhesive protein-
Fibronectin

21. Muscle Tissue
•Muscletissueisaspecializedtissuefoundinanimalswhichfunctionsby
contracting,therebyapplyingforcestodifferentpartsofthebody.
•Muscletissueconsistsoffibersofmusclecellsconnectedtogetherinsheets
andfibers.

22. Function of Muscle Tissue
•Muscletissuefunctionsasasingleunit,andisoftenconnectedtothesame
nervebundles.Anerveimpulsetravelingfromthebrainoranotheroutside
signaltellsthemuscletocontract.Thenerveimpulseistransferredalmost
instantaneouslytoallthenervecellsinthemuscletissue,andtheentire
musclecontracts.
•Atthecellularlevel,eachmusclecellhasacomplexofproteinscontaining
actinandmyosin.Theseproteinsslidepastoneanotherwhenthesignalto
contractisreceived.
•Thefilamentsareconnectedtotheendsofthecells,andastheyslidepast
oneanother,thecellcontractsinlength.Asinglecellcancontractupto70%
inlength,whichshortenstheentiremusclewhencontractionhappens.
Muscletissuecanbeusedtomovebones,compresschambers,orsqueeze
variousorgans.

23. Types of Muscle Tissue
SkeletalMuscleTissue
•Skeletalmuscletissueisatypeofstriatedmuscle,meaningclearbandscan
beseeninitunderamicroscope.
•Thesetinylightanddarkbandsaresarcomeres,highlyorganizedbundlesof
actin,myosin,andassociatedproteins.
•Theseorganizedbundlesallowstriatedmuscletocontractquicklyand
releasequickly.Muscletissueisattachedtothebonesthroughtendons,
whicharehighlyelasticportionsofconnectivetissue.Manymusclesmay
seemtocontrolasingleappendage,butinrealityeachoneonlycontrolsone
smallaspectofmovement.Skeletalmuscletissuecanbecontrolled
voluntarily,bythesomaticnervoussystem.Theothertypesofmuscleare
controlledmainlybytheinvoluntaryorautonomousnervoussystem.

24. CardiacMuscleTissue
•Whilethestriationsinskeletalmuscletissueareevenandparallel,
complexandbranchingstriationsareseenincardiacmuscletissue.
•Whilethestriationsarehardtoseeinthisimage,thebranchingnatureof
thecellsiseasytopickout.
•Thebranchingiscausedbytheconnectionofcardiacmusclecellstoone
another.Thecellsareconnectedviaintercalateddiscs.Thesejunctures
helpcardiacmuscletocontractasoneandprovidearapidand
coordinatedcontractiontomoveblood.

25. SmoothMuscleTissue
•Unlikecardiacandskeletalmuscletissue,smoothmuscletissuehasno
striations.Thefibersofmyosinandactininsmoothmusclefiberisnot
nearlyasorganizedasintheothertypesofmuscletissue.Insmooth
muscle,thecontractionsarenotquickandrapidbutrathersmoothand
continuous.Smoothmuscleisfoundsurroundingmanyorgans,blood
vessels,andothervesselsusedfortransportingfluids.Thesmooth
musclecancontracttoapplyaforceonorgan.Thiscanbeusedtomove
bloodorfoodthroughouttheirrespectivesystems.Smoothmuscleis
recognizablefromitslackofstriationsandunbranchingnatureinimage
(b)below.

26. Nervous Tissue
•Nervoustissueisthetermforgroupsoforganizedcellsinthenervous
system,whichistheorgansystemthatcontrolsthebody'smovements,
sendsandcarriessignalstoandfromthedifferentpartsofthebody,and
hasaroleincontrollingbodilyfunctionssuchasdigestion