SkeletalSkeletal – striated, multinucleate, voluntary,
SmoothSmooth - found in walls of hollow visceral organs; ex. stomach, bladder, respiratory passages; visceral, nonstriated, involuntary; discuss peristalsis
CardiacCardiac – in heart only, striated, involuntary, intercalcated disks
Muscle function:• produce movement• maintain posture• stabilize joints• generate heat
Functional Characteristics:• Excitability- respond to a stimulus• Contractility- ability to shorten
forcibly when adequately stimulated • Extensibility- the ability to be
stretched• Elasticity- the ability of a muscle
fiber to resume its resting length after being stretched
Skeletal Muscle Skeletal Muscle TissueTissue
Smooth Muscle Smooth Muscle TissueTissue
Cardiac Muscle Cardiac Muscle TissueTissue
Gross Anatomy Skeletal Muscle
bundle of muscle fibers
muscle fiber(cell)
myofibril
sarcomere
Muscle Muscle AnatomyAnatomy
Muscle Fiber
Myofibril
SarcomereSarcomere
Z lines
SarcomeSarcomerere A band
SarcomeSarcomerere I bands
SarcomeSarcomerere H zone
Actin and Myosin FilamentsActin and Myosin Filaments
myosinactin
Myosin (Thick) FilamentMyosin (Thick) Filament
Actin (Thin) FilamentActin (Thin) Filament
Sliding Filament HypothesisSliding Filament Hypothesis
A
Z ZH
I I
AI I
Z ZH
Z ZHAI I
Actin & Myosin InteractionActin & Myosin Interaction
Biology 100Biology 100Human BiologyHuman Biology
Motor UnitMotor Unit
spinal cord
motor neurons
muscle bundle
muscle fibers
neuromuscular junctions
Neuromuscular Neuromuscular junctionsjunctions
branching axon branching axon to motor unitto motor unit
muscle fibersmuscle fibers
axon
plasma membrane
myofibrils
sarcomere
T tubules
sarcoplasmic reticulum
http://www.blackwellpublishing.com/matthews/myosin.html
Stimulation of Skeletal Muscle