Myology: The Study of Muscles (Anatomy: 1st Semester Lecture 5)
-
Upload
osama-zahid -
Category
Education
-
view
1.283 -
download
3
description
Transcript of Myology: The Study of Muscles (Anatomy: 1st Semester Lecture 5)
Lecture 5
Muscle tissue, Structure of skeletal muscle, Classification
Muscle Tissue: Composed of contractile unites possessing the properties of
ExcitabilityContractilityExtensibilityElasticity
Functional Unit:
Muscle fiber
Smooth muscle fiber VisceralStriated muscle Skeletal / Cardiac
Skeletal Muscle
Functions: Provides force for Movement and PostureStabilizes JointsGenerates heat
AttachmentsOrigin /Insertion
Direct/Indirect (Tendon/Aponeurosis)Transmits forces (Fiber orientation?)
BellyGenerates force
StructureFiber covered by Endomysium—SarcolemmaFascicle covered by PerimysiumMuscle covered by Epimysium Epitenon
Muscle force is a function of
Number of muscle fibersPennation Angle
Pennation Angle
Unipennate MusclesBipennate MusclesMultipennate Muscles
Multipennate Bipennate
Accessory StructuresFasciaBursaTendon Sheath
Extensive Blood Supply
Extensive Innervations:Motor UnitSpindles/Golgi tendons endings/free nerve endings/Paciniancorpuscles
Regeneration of muscle tissue is possible
Spindle-shaped (fusiform)
Sheet like (planus)
CLASSIFICATION
Shapes
CLASSIFICATION
Functional: Prime Movers / AgonistsSynergistAntagonists
Specific Action:Flexor/ExtensorAdductor/AbductorSupinator/PronatorSphincter/DilatorLevator/DepresssorRotator
Number of joints crossed: UniarticularBiarticularPolyarticular
Developmental Origin and Innervation:
Somatic muscles – somatic motor innervationVisceral muscles – visceral autonomic motor innervation
Composition:
White fibers: More myofibrils more forceLess myoglobin short duration
Red Fibers: Less myofibrils weak force More myoglobin long duration
NAMING CONVENTIONS
ActionShapeRegional LocationDirection of fibersNumber of headsNumber of belliesAttachment sitesRelative position