MyologyChapter 3effect by means of the tendons, aponeuroses, andfascia. Skeletal muscles are also called voluntarySection 1Introduc-muscles, since their contraction is controlled by thetionconsciouness (Fig.I-3-1, 2) . Muscle tssue accountsfor approximately 40% of the body weights. As eachIn this chapter the skeletal muscles will be dis-skeletal muscle possesses a definite shape, structure,cussed. The skeletal muscles are the muscles attachedlocation and accessory apparatus, and is supplied byto the bone, fascia or skin. Motor ability provides or-abundant blood vessels, lymphatics and nerves, it canganisms with a means of reacting to the environment.be regarded as an organ.The contraction of skeletal muscles is a mechanicalFrontal bellyofoccipitofrontalisOrbicularis oculiocleidomastoidGreatersupraclaClavicleDeltoidPectoralis majorDeltoidBicepsbrachiiBiceps brachiiObliquus extemusabdominisCubital fossaBrachioradialisInguinal canalRectusabdominisTendonof palmaris longuSartoriusThenuadricepsfemorisHypothenarPatellaPatellaPatellar lig.PatellarligTibialis anteriorAnteriorborderof tibiaExtensordigitorumlongusFig. I-3-1 Surface anatomy and muscles of the body (anterior view). 82:扫描全能王创建
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MFChapter3Myology·83·OccipitalbellyofoccipitofrontalisSpineof scapulaTrapeziusDeltoidAcromioneresmajorTriceps brachiiTriceps brachiiOlecraLatissimus dorsiExtensorcarpiradialislongusIliaccreExtensordigitorumGluteus maximtGluteusmaximusHead of ulnaBicGluteal sulclliotibialtractSemitendinosusPopliteal fossaSemimembranosusI港可GastrocnemiusendocalcaneusLateral malleolusFig.I-3-2 Surface anatomy and muscles of thebody (posterior view)vary extremely in their shape. It may be long, short,broad or circular-band-like (sphincter).Some mus-I . Morphology of Skeletalcles have more than one belly or one origin.Some shape is related to the fibers and long axisMuscleof the muscles.The fibers are oblique to the long axisof the muscle.When muscle fbers resembling half aThe muscle fibers or cells are the smallest struc-feather and have a linear or narrow origin, they aretural unit of a muscle. The connective tissue thatcalled the unipennate muscle and when the fiberswraps the muscle fibers,bundle of muscle fibers andarise from a broad surface resembling a whole featherthe muscle is called the endomysium, perimysiumthey are called the bipennate muscles and when septaand epimysium, respectively. The fleshy part of aextending into the attachments of the muscles and di-muscle is often called the belly. At each end of theviding them into several featherlike portions they aremuscle, the connective tissue blends with the strongcalled the multipennate muscles (Fig.1-3-3).collagen bundles to form the tendon. The muscles可口扫描全能王创建
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·84PARTILOCOMOTORSYSTEMTendon of muscleBellyEInterBellmediateBtendonTUNOrbicularmuscleTendon Short muscleDigastric muscleFlate muscleLongmuscleTendonTriceps muscleBipennatemuscleBiceps muscleMultipennatemuscleUnipennatemuscleFig.I-3-3 The yarious shapes of muscleimal parts of a limb while movements are occurringin distal parts.Amuscle may act as a prime mover,I.Oriqin,Insertion and Ac-antagonist, synergist orfixatorunder different condi-tionof Skeletal Musclestions.Each skeletal muscle has at least two attachmentsII. Nomenclature of Musclesto some part of the skeleton, mucous membrane orskin.For purposes of description,most of musclesThe muscles have been named by their shape, lo-are commonly described as having an origin and ancation, action, attachments, direction, number of partsinsertion.The origin is usually a fixed attachment and so on. The trapezius and rhomboid muscle areof the muscles, while the insertion may be movable.However, some muscles may act in both directions innamed for their shapes. The levator scapulae is nameddifferent circumstances. Therfore, in most cases, it isfor its action in lifing the scapula. The gluteus maxi-best to use the terms proximal attachment and distalmus, gluteus medius and gluteus minimus are namedattachment, instead oforigin and insertion.because of theirlocation in the gluteal region and forControlled by nervous system, the skeletal mus-their contrast in size. The sternocleidomastoid musclecular cells (fbers) and tssues work together to movehas attachments to the sternum, the clavicle, and theparts of the body. During movements of the body,mastoid process of the temporal bone. The numberofthe main muscles are called prime movers or ago-heads of the origin is indicated by the terms, for ex-nists. They contract actively to produce the desiredample the quadriceps femoris.movement. The muscle that opposes the action of aprime mover is called antagonist. As a prime moverIV . Supplementary Struc-contracts, the antagonist progressively relaxes, so thetures of Musclesmovement is produced smoothly.The antagonistsmay protect the joint from injury. The muscles whichThey include the fascia, the synovial bursa, thecooperate in performing an action are called syner-gists. Other muscles, called fixators, steady the proxsynovial sheath oftendon and sesamoid bones.A2R扫描全能王创建口
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Chapter3Myology ·85.insulation and a store of energy for metabolic useFasciaSubcutaneous nerves,vessels,lymphatics and skin店muscles arefound in the superficial fascia.It is formed by the connective tissue. There are(2) Deep fasciasuperficial and deep groups of fascia in the body (Fig.1-3-4) .They are also composed of collagenous fibers,but dense and inelastic,and arranged to regular fiber(1)Superficial fasciamembrane. The deep fascia may form a strong sep-arate sheath surronding muscles or the vessels andIt is found immediately under the skin and cov-nerves. In the limbs they give off septa which separateers almost the entire body. It is a layer of variablethe functional groups of muscle by attaching alongthickness which contains fat. In the scalp, the palmthe longitudinal axis of a bone. These fascia sheetsof hand and the sole of foot, the superficial fascia isare called intermuscular septa. In certain situationsvery dense, and it is so thick that superficial fascia isthe deep fascia affords attachment for muscles. It iscapable of being subdivied into several laminae in thethickened at the wrist and ankle to form the retinacu-groin. It provides for increased mobility of skin, andlum that maintains its underlying tendon.the adipose component, which contributes to thermalSkinSuperficialfasciaSheath of fasciaDeepfasciaSheathfor vesselsand nerveHumeruMuscular septumFig.I-3-4 The fascia of the musclesurrounding a tendon, which is usually found in thehand and foot.It consists of twoparts.Theouterfi-Synovial bursabrous sheath is formed by thickened deep fascia thatrestricts the tendon to the surface ofabone.The innerThe synovial bursa is a sac containing synovialsynovial sheath is formed by double-layered synovialfluid. It is often found between a tendon and a bonemembrane. The outer parietal layer lines the inneror a ligament, or between two tendons. This is a spe-surface of the fibrous sheath and the inner visceralcialized structure that functions to reduce friction,layer surrounds the tendon. The two layers are con-allowing an effcient freedom of motion between con-tinuous at the bottom of the sheath, thus forming themesotendon to allow vessels and nerves to reach thetiguous connective tissue surfaces.tendon. The parietal and visceral layers of the syno-vial sheath is lubricated by a film of synovial fluid to.Tendinous sheathreduce friction while the tendon moving in the sheath.(Fig. I-3-5).The tendinous sheath is a connective tissue sheath扫描全能王创建
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Chapter3Myology.87.extends it, and rotates it medially.traction of this muscle pulls the arm posteriorly, orSemispinalis capitisStemocleidomastoidSplenius capitis-Levator seapulaeSupraspinatusTrapeziuRhomboidasisDeltoidInfraspinatusTeresminorTeres majorTriangle of ausculationSerratus anteriorSerratus posterior inferiorLatissimus dorsiSuperficial layer of thoraco lumbarfasciErrector spinaeObliquus extermus abdominisObliquusinternusabdominisSublumbar triangleGluteusmediusGluteus maximusFig.I-3-6 Themuscles of back3.Levator scapulae4.Rhomboid musclesThis narrow elongated muscle is situated at theThis muscle may be divided into rhomboide-dorsal and lateral part of the neck (Fig.I-3-6). It aris-us major and rhomboideus minor (Fig.I-3-6).Thees by tendinous slips from the transverse processesrhomboideus major arises tendinous fibers from theof the atlas and axis and from the posterior tuberclesspinous processes of the second to fifth thoracic ver-of the transverse processes of the third and fourthtebrae. The fibers course inferolaterally to be insertedcervical vertebrae. It descends deep to the sternoclei-by a narrow tendinous arch to medial border of thedomastoid muscle, along the floor of the posteriorscapula to the inferior angle of the scapula below.Thetriangle of the neck, and then under cover of the tra-rhomboideus minor arises from the inferior part of thepezius to be inserted into the vertebral border of theligamentum nuchae and from the spinous processesscapula, between the superior angle and the triangularof the seventh cervical and first thoracic vertebrae.smooth surface at the root of the spine. The muscleIts fibers course inferolaterally just superior to thecan elevate the superior angle of the scapula,tends torhomboideus major to be inserted into the base of thedraw the scapula medially, and rotates it so as to low-root of the spine edge of the scapula. They adduct theer the lateral angle. With the scapula fixed, the levatorscapula by pulling it medially toward the vertebralScapulae bends the neck laterally and rotates it slight-column and also support the scapula by elevating it.lytoward the same side.口R扫描全能王创建口
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