Muscular Tissue
Muscular Tissue uscular Tissue uscular Tissue
ContentsMuscular TissueSkeletal MuscleCardiac MuscleSmooth Muscle
Skeletal Muscle Smooth Muscle Contents Cardiac Muscle Muscular Tissue
IntroductionMuscleCompositionMuscle cellsConnectivetissuecap.,lymphaticv,nfClassificationStriated mSkeletal m → voluntary mCardiacminvoluntary mUnstriatedm.Smoothm
Introduction Composition Muscle cells Connective tissue cap., lymphatic v, nf Classification Striated m Skeletal m Striated m Skeletal m Cardiac m Cardiac m Unstriated m Smooth m Unstriated m Smooth m voluntary m. voluntary m. involuntary m involuntary m Muscle
ActivityMuscletypesSkeletalmuscleCrosssectionsStrong,quickdiscontinuousvoluntarycontractionStriatedmNucleiCardiacmuscleStrong,quickcontinuousinvoluntarycontractionIntercalateddisksSmoothmuscleWeak,slowinvoluntary0contractionE
Striated m
SpecificterminologyMuscle cell -....- muscle fibreMembrane ..... sarcolemmaCytoplasm .... sarcoplasmSER ---..-Ssarcoplasmic reticulum
Muscle cell - muscle fibre Membrane - sarcolemma Cytoplasm - sarcoplasm SER - sarcoplasmic reticulum Specific terminology
SkeletalMusclestructureShape: Long, cylindrical cellsNu:flattened,MultinucleatedbeneathsarcolemmaSarcoplasm: myofibrils;crossstriationsalternatingdark and light bands
structure Shape: Long, cylindrical cells Nu: flattened, Multinucleated, beneath sarcolemma Sarcoplasm: myofibrils; cross striations alternating dark and light bands Skeletal Muscle
1)myofibrilsAbandZ lineIbandLMlightband=Ibanddarkband=AbandA band, I band, Z line,H band, M lineSarcomereSarcomere:1/2 /+ A + 1/2 Ishortestcontractileunitofskeletalmuscle.MusclefibreMyofibrils
A band, I band, Z line, H band, M line Sarcomere: 1/2 I + A + 1/2 I shortest contractile unit of skeletal muscle. A band Z line I band • light band= I band •dark band =A band LM 1) myofibrils Sarcomere
EMlongparallel,cylindricalfilamentousbundles(thin & thick)consisting of two types of myofilamentAHZ line1MlineHSarcomere
EM long , parallel , cylindrical filamentous bundles consisting of two types of myofilament (thin & thick) H Z line A I M line Z Z H Sarcomere
a.Thickfilamentsoccupying A band, fixation M linemyosinmoleculesrods overlap; globular heads direct toward eitheroftheendsformingcrossbridgesandhaveATPaseactivitySarcomereAbandHbandZdiskTitinNebulinm band
a. Thick filaments occupying A band, fixation M line myosin molecules rods overlap; globular heads direct toward either of the ends forming cross bridges and have ATPase activity
b.Thin filamentsOneendisattachedtothe Zline,theotherreachtothelateralendofHbandIbandAbandIbandendend-Composed ofHzoneactin,ActinfilamentThickfilamenttropomyosin+end-+endtroponin (Tnl,TnT,TnC)DisActinmonomersTropomTroponithin.filaTroponinsubunitsSwitahpartofTnlMyosin-bindingpartofthefilamentthe filamentTnoTnT
b. Thin filaments One end is attached to the Z line, the other reach to the lateral end of H band Composed of actin, tropomyosin troponin (Tnl,TnT,TnC)