PRACTICAL ROADMAP MUSCLE WJ van der Spuy
MUSCLE Skeletal (striated) Cardiac (striated) Smooth Identification based on Fiber size, shape and presence/absence of branching Number, shape and position of nuclei Presence or absence of cross-striations
MUSCLE Skeletal Cardiac Smooth Cell Elongated Branching Spindle-shaped Nucleus Multiple peripheral Single or binucleated central Single central Striations Cross-striated Cross-striated & Intercalated disks None Motor Control Voluntary Involuntary Involuntary
SKELETAL MUSCLE Slide 76 Striated Skeletal Muscle Tongue Iron haematoxylin stain
Organisation Endomysium - surrounding muscle fibre Muscle fibre Epimysium - surrounding muscle Perimysium - surrounding fascicle Fascicle 100µm Scanning Electron Micrograph WJ van der Spuy MSc
Fibre Orientation Longitudinal section Transverse section
Identification Fibroblast nuclei in connective tissue sheath Cross-striations Multiple peripheral nuclei Muscle fibre Muscle fibre
Striations I band (light striation) bisected by dark Z line A band (dark striation) bisected by light H band
SKELETAL MUSCLE Slide 50 Musculo-tendinous junction H&E stain
Musculo-tendinous Junction Dense regular connective tissue Skeletal Muscle Musculo-tendinous junction with fibres inserting obliquely into tendon
SKELETAL MUSCLE Slide 4 Neuromuscular (myoneural) junction Snake H&E and gold impregnation staining
Neuromuscular Junction Axon Boutons (neuromuscular junction) Motor Nerve (neuromuscular bundle in longitudinal section) Striated skeletal muscle fibres Neuromuscular bundle (transverse section) Micrograph WJ van der Spuy MSc Stain: Toluidine blue ph=11.5 Blood vessel
Neuromuscular Junction Motor nerve Axon boutons
Muscular Dystrophy Limb-Girdle Muscular Dystrophy type 2B (LGMD2B) Increased rate of regeneration in response to ongoing degeneration of muscle Characterised by: Variation in fiber size Necrosis of muscle tissue Revascularisation Inflammatory cell infiltration Phagocytosis of necrotic debris Proliferation of mononuclear muscle precursors Fusion of precursors to form myotubes
LGMD2B CN: Central nucleus Regenerating fibre PI CN FL FS: Fibre splitting Early hyperplasia FL: Fibre lobulation Late hyperplasia PN LI: Leukocyte infiltration Inflammation NF: Necrotic fibre Degenerating fibre FS PI: Postnecrotic infiltrate Clearing debris after degeneration LI Micrograph WJ van der Spuy MSc Stain: Toluidine blue ph=11.5 SC NF 10µm SC: Satellite cell Mononuclear muscle precursor regenerative ability PN: Peripheral nucleus Mature fibre
CARDIAC MUSCLE Slide 57 Heart (interventricular septum) Iron haematoxylin stain
Fibre Orientation Longitudinal section Transverse section
Identification Cross-striations Fibre branching Intercalated discs Central nuclei
Interventricular Septum Capillaries with black stained RBCs Purkinje fibres Myocardium with ordinary cardiac muscle fibres Endocardium Lumen of left ventricle
Purkinje Fibres Pale-staining fibres Nucleus Large glycogen space around nuclei
Ordinary Cardiac Muscle Fibres Dark-staining fibres Nucleus Smaller glycogen spaces around nuclei
CARDIAC MUSCLE Slide 86 Heart H&E and elastic stain
Interventricular Septum Myocardium with ordinary cardiac muscle fibres Purkinje fibres Endocardium
Interventricular Septum Myocardium with ordinary cardiac muscle fibres Purkinje fibres Nucleus Nucleus Large glycogen space around nucleus Small glycogen space around nucleus
SMOOTH MUSCLE Slide 10 Smooth muscle Uterus (baboon) H&E stain
Overview Endometrium Myometrium with smooth muscle
Fibre Orientation Longitudinal section Transverse section
Identification Cigar-shaped nucleus centrally located in spindle shaped fibre Longitudinal section Transverse section
Smooth Muscle vs. Connective Tissue Blood vessel with smooth muscle wall Irregular dense connective tissue Myometrium with smooth muscle