SmoothSmooth musclemuscle (HE)(HE)

SkeletalSkeletal musclemuscle ((crosscross sectionsection HE)HE)

SkeletalSkeletal musclemuscle ((longitudinallongitudinal sectionsection HE)HE)

CardiacCardiac musclemuscle (HE)(HE)

CardiacCardiac musclemuscle ((ironiron--hematoxylinhematoxylin))

SmoothSmooth musclemuscle HM, HM, 40x 40x (HE)(HE)SmoothSmooth musclemuscle cellcell ((oneone nucleusnucleus, , thinthin, , bobbinbobbin shapeshape))The The cellscells arrangedarranged inin fasciculifasciculi..The The nucleusnucleus is is localisedlocalised inin thethe centre centre ofof thethe cellcell. . ThereThere areare no no striatedstriated

Smooth muscle nucleus

The The functionalfunctional unit unit ofof itit is is thethe muscularmuscular fibrefibreThereThere is a is a fusionfusion ofof thethe myoblastmyoblast cellscells duringduring thethe ontogenesisontogenesisThe The numbernumber ofof nucleinuclei maymay be more be more thanthan 100100

Epimysium

EndomysiumPerimysium

(Cohnheim field)

SkeletalSkeletal musclemuscle crosscross sectionsection, 20x (HE), 20x (HE)

SkeletalSkeletal musclemuscle crosscross sectionsection, 40x (HE), 40x (HE)

The The bandsbands, , whichwhich areare dyeddyed darkdark, show a , show a doubledouble refractionrefraction ofof lightlight. . ThatThat sswhywhy thesethese areare AnisotropesAnisotropes (A)(A)The The bandsbands, , whichwhich areare dyeddyed lightlight, , havehave singlesingle refractionrefraction ofof lightlight IsotropesIsotropes (I)(I)ThereThere is a is a thinthin lineline inin thethe middlemiddle ofof thethe II--bandband, , whichwhich is is calledcalled ZZ--bandbandThereThere is a is a lighterlighter lineline inin thethe middlemiddle ofof thethe AA--bandband, , whichwhich is is calledcalled HH--bandbandandand int he int he middlemiddle ofof thisthis lighterlighter lineline therethere is a is a darkdark lineline, , thethe MM--lineline..The The II--bandband becomesbecomes shortershorter whenwhen thethe musclemuscle contractscontracts

ThoseThose contractilecontractile elementselements whichwhich show show striatedstriated patternpattern is is calledcalledmyofibrilsmyofibrils..The The placeplace whichwhich is is betweenbetween twotwo ZZ--bandsbands isis calledcalled sarcomersarcomerThe The myofibrillummyofibrillum consistsconsists ofof myofilamentsmyofilaments..

thinthin (9 (9 nmnm actinactin))

thickthick (12(12--15 15 nmnm myosinmyosin))

HarHaráántcsntcsííkolt izom HM, 40x (HE)kolt izom HM, 40x (HE)

Muscle cell nuclei

Striated pattern

Fibrocyte nucleus

SkeletalSkeletal musclemuscle ((longitudinallongitudinalsectionsection, 40x (HE), 40x (HE)

CardiacCardiac musclemuscle HE 60xHE 60xSingleSingle muslemusle cellscells, , therethere areare cellcell connectingconnecting structuresstructures atat thethe endend ofof themthemThreeThree otherother cardiaccardiac muslemusle cellcell cancan attachattach toto oneone cardiaccardiac musclemuscle cellcell ((YY--shapeshape))EberthEberth ss-- lineslines, , striatedstriated patternpattern

WeWe differenciatedifferenciatebetweenbetween twotwo part part lineslines becausebecause ofof thetheterracedterraced structurestructure

TransversalTransversal partpart: : fasciafascia adherensadherensdesmosomesdesmosomes

LongitudinalLongitudinal partpart::nexus (nexus (gapgap--junctionjunction))

theythey areare responsibleresponsibleforfor ionicionic traffictraffic

Cardiac muscle EM 29500x

Eberth s-line

nucleus

CardiacCardiac musclemuscle 60x60x