Presentation on theme: "The Muscular System Structural and functional organization of muscles"— Presentation transcript:
1The Muscular System Structural and functional organization of muscles The system of the little mouse
2Structural and Organization of Muscles 600 Human skeletal musclesAlso smooth & cardiac musclesGeneral structural & functional organizationfunctions of muscleconnective tissues of musclegeneral anatomy of skeletal musclesmuscle shape and functioncoordinated actions of muscle groupsintrinsic and extrinsic musclesmuscle innervation
3The Functions of Muscles Movement of body parts and organ contentsMaintain posture and prevent movementCommunication - speech, expression & writingControl of openings and passagewaysBody heat production
6Connective Tissues of a Muscle TendonDeep fasciaEpimysiumPerimysiumEndomysium
7Connective Tissues of a Muscle Epimysiumcovers whole muscle bellyblends into connective tissue that separates musclesPerimysiumslightly thicker layer of connective tissuesurrounds a bundle of cells called a fascicleEndomysiumthin layer of areolar tissue surrounding each cellallows room for capillaries and nerve fibers
10Location of Fascia Deep fascia found between adjacent muscles Superficial fascia (hypodermis)found between skin and musclescontains adipose tissueSuperficial FasciaDeep Fascia
11Muscle Attachments Direct (fleshy) attachment to bone epimysium is continuous with periosteumintercostal musclesIndirect attachment to boneepimysium continues as tendon or aponeurosis that merges into periosteum as perforating fibersbiceps brachii or abdominal muscleAttachment to dermisStress will tear the tendon before pulling the tendon loose from either muscle or bone
12Parts of a Skeletal Muscle Originattachment to stationary end of muscleBellythicker, middle region of muscleInsertionattachment to mobile end of muscle
13Skeletal Muscle Shapes Fusiform musclesthick in middle & tapered at endsbiceps brachii m.Convergent musclebroad at origin and tapering to a narrower insertionParallel musclesparallel fasciclesrectus abdominis m.
14Skeletal Muscle Shapes (2) Circular musclesact as sphinctersring around body openingorbicularis orisPennate musclesfascicles insert obliquely on a tendonunipennate, bipennate or multipennatepalmar interosseus, rectus femoris & deltoid
15Biceps Tendon Rupture: As a result of chronic tendonitis or truama, the long head of the biceps may rupture. When this occurs, the biceps muscle appears as a ball of tissue and there is a loss of function.
23Terrell Owens, leaving the field and wincing in pain after suffering a regular season ending, lower leg injury against the Cowboys.
24↑Terrell Owens has been kicked 800 feet up in the air by the lower leg of Chuck Norris
25Coordinated Muscle Actions Prime mover or agonistproduces most of forceSynergist aids the prime moverstabilizes the nearby jointmodifies the direction of movement that occursAntagonistopposes the prime moverpreventing excessive movement and injuryFixatorprevents movement of bone that prime mover is attached toExample
26Muscle Actions during Elbow Flexion Prime mover (agonist) = biceps brachii m.Synergist = brachialis m.Antagonist = triceps brachii m.Fixator = muscle that holds scapula firmly in place such as rhomboideus m.Definitions
27Methods used to diagnose structural muscle disorders Myopathies: Muscle disordersCan be confused with skeletal/nervous disordersPhysical testsCan you lift against gravity?Can you lift against resistance?Can you lift repeatedly?Physicians judge the amount of force and assign a grade; percentage, verbal grade, or numeric
29Myometers/Dynometers measure the amount of force a muscle exerts MRIs distinguish soft tissues making them more useful than X-RaysElectromyography records electrical activity of a muscleBiopsies: remove a small tissue sample
30Blood and Urine tests Show muscle enzymes that have leaked into blood Creatine KinaseLactate DehydrogenaseAldolaseAspartate transaminaseChanges in conc. of electrolytes which are usually more conc. in skeletal muscle than blood.How much muscle myoglobin is in the urine.
31Creatine kinase (CK)Its function is the catalysis of the conversion of creatine to phosphocreatine.Where do you think the phosphorous comes from?Creatine/Phosphocreatine help buffer fluctuations in ATP usage.Studies suggest taking creatine can improve muscle performance under high energy aerobic trainingCreatine use is not considered doping and is not banned by sport-governing bodies. In some countries however, like France, creatine is banned.
32Structural Disorders of Skeletal Muscle Rhabdomyolysisthe breakdown of muscle due to injury, either mechanical, physical or chemical. The principal result of this process is acute renal failure due to accumulation of muscle breakdown products in the bloodstream, several of which are injurous to the kidney. Treatment is with intravenous fluids, and dialysis if necessary.
33Photomicrograph of muscle biopsy sample shows swollen and necrotic muscle fibers without any inflammatory infiltrate
34CautionThings get gross from here on out. Feel free to look at something calming.
35A hematoma is a collection of blood under the skin A hematoma is a collection of blood under the skin. It can occur in any soft tissue such as skin or muscle. A hematoma is caused when blood leaks from an injured vessel.Edema is the medical term for swelling as a result of fluid in the skin or muscle.
36Contracture: Abnormal shortening of muscles Dupuytren's contracture is a fixed flexion contracture of the hand where the fingers bend towards the palm and cannot be fully extended.
37Myositis Muscle inflammation Viral, bacterial, or parasitic infectionTrichinois: Larva of parasitic rounworms Tricinella get encysted in muscles.Caused by eating undercooked pork or bear~ 12 cases a year in US~500 cases a year in Thailand
38PolymyositisDegenerated skeletal muscle fibers (amorphous pink) with infiltrating macrophages and regenerating fibers with multiple nuclei and more lavender cytoplasm.
39Crush injuries are associated with significant mechanisms of injury Crush injuries are associated with significant mechanisms of injury. If a force is great enough, soft tissue (muscles, vessels, skin) can be crushed leading to extensive tissue damage and subsequent swelling and pain. Crush injuries in the lower extremities and forearm can lead to compartment syndrome that generally takes a few hours to develop.
40In the eyes of a ranger, The unsuspecting stranger, Had better know the truth of wrong from right, 'Cause the eyes of a ranger are upon you, Any wrong you do, he's gonna see, When you're in Texas, look behind you, 'Cause that's where the rangers gonna be.
41Intrinsic and Extrinsic Muscles Intrinsic muscles are contained within a region such as the hand.Extrinsic muscles move the fingers but are found outside the region.
42Skeletal Muscle Innervation Cranial nerves arising from the brainexit the skull through foraminanumbered I to XIISpinal nerves arising from the spinal cordexit the vertebral column through intervertebral foramina
43How Muscles are Named Nomina Anatomica system of Latin names developed in 1895updated since thenEnglish names for muscles are slight modifications of the Latin names.Table 10.1 = terms used to name musclesdigiti = of a fingerlevator = elevates a body partprofundus = deepestquadriceps = having 4 heads
44Learning StrategyExplore the location, origin, insertion and innervation of 160 skeletal muscles using the tabular information in this chapter.Increase your retention & understanding by:examining models and photographic atlasespalpating yourself using the images in Atlas Bobserve an articulated skeletonsay the names aloud and check your pronunciation
46Muscles of Facial Expression Small muscles that insert into the dermisInnervated by facial nerve (CN VII)Paralysis causes face to sagFound in scalp, forehead, around the eyes, nose and mouth, and in the neck
47Muscles of the Scalp and Forehead FrontalisOccipitalisOccipitofrontalis is found in the scalp. Frontalis m. raises the eyebrows while Occipitalis m. fixes the galea aponeurotica
48Muscles around the Eyes Corrugator superciliiProcerusOrbicularis OculiNasalisOrbicularis oculi closes the lips. Corrugator draws the eyebrows together. Procerus pulls down the skin of forehead. Nasalis widens nostrils.
49Muscles around the Mouth Orbicularis oris encircles mouth & other mm blend into itLevator & depressor of labii (lip) & anguli (angle of mouth)Risorius & zygomaticus curl corner of mouth up in smileBuccinator keeps food on top of teeth, blowing & suckingLevator labii superiorisZygomaticus majorBuccinatorRisoriusDepressor anguli orisOrbicularis orisDepressor labii inferioris
52Musculature of the Tongue Intrinsic muscles = vertical, transverse & longitudinalExtrinsic muscles connect tongue to hyoid, styloid process, palate and inside of chinTongue shifts food onto teeth & pushes it into pharynxIntrinsic tongue musclesExtrinsic tongue muscles
53Muscles of Mastication 4 Major musclesArise from skull & insert on mandibleTemporalis & Masseter elevate the mandibleMedial & Lateral Pterygoids help elevate, but produce lateral Swinging of jaw used to grind with molarsTemporalisMasseterLateral pterygoidMedial pterygoid
54Suprahyoid Muscles and Swallowing Digastric and Mylohyoid = open mouthGeniohyoid = widens pharynx during swallowingStylohyoid = elevates hyoidThyrohyoid (an infrahyoid m.) = elevates larynx, closing glottisDigastricMylohyoidStylohyoidThyrohyoid
56Other Muscles involved in Swallowing Pharyngeal constrictorsPharyngeal constrictors push food down throatInfrahyoid muscles pulls the larynx downwardIntrinsic laryngeal muscles used to control speech
57Muscles of Respiration Breathing requires the use of musclesdiaphragmexternal intercostal musclesinternal intercostal musclesContraction of the first 2 produces InspirationContraction of the last produces Forced ExpirationNormal Expiration requires little muscular activityelastic recoil of tissues and gravity collapsing the chestonly inspiratory muscles active in braking action, so exhalation is smooth
58Muscles of Respiration -- Diaphragm Central tendonMuscular dome between thoracic and abdominal cavitiesMuscle fascicles extend to a fibrous central tendonContraction flattens itincreases the vertical dimension of the thorax drawing air into the lungsraises the abdominal pressure to help expel urine, feces and facilitating childbirth
59Muscles of Respiration -- Intercostals External intercostalsextend downward and anteriorly from rib to ribpull ribcage up & outward during inspirationInternal intercostalsextend upward and anteriorly from rib to ribpull ribcage downward during forced expiration
60Muscles of Respiration - Serratus Serratus posterior superiorelevates ribs 2-5 during inspirationSerratus posteriori inferiordepresses ribs 9-12 during inspiration
61Muscles of the Abdomen 4 Pairs of sheetlike muscles Functions external obliqueinternal obliquetransverse abdominisrectus abdominisFunctionssupport the viscerastabilize the vertebral columnhelp in respiration, urination, defecation & childbirth
64Superficial Muscles of the Back SemispinalisSplenius Levator scapulae RhomboideusSupraspinatusInfraspinatusTeres majorGluteus maximusGluteus mediusTrapeziusLatissimus dorsi
65Muscles of the Back Erector spinae group Semispinalis 3 columns muscleextends from sacrum to ribsextends vertebral columnSemispinalis groupvertebrae to vertebraeextends neckMultifidisrotates vertebral columnQuadratus lumborumilium to 12th riblateral flexionSemispinalisErector spinaeMultifidisQuadratus lumborum
66Muscles of the Pelvic Floor 3 Layers of muscles span pelvic outletsupport pelvic visceraRegion is called perineumdiamond-shaped region bounded by pubic symphysis, coccyx and ischial tuberositiespenetrated by anal canal, urethra & vaginaanteriorly = urogenital triangle; posteriorly= anal triangle3 Layers or compartments of the perineumsuperficial layer = Superficial perineal spacemiddle layer = Urogenital diaphragm & Anal sphincterdeep layer = Pelvic diaphragm
67Muscles in Superficial Perineal Space IschiocavernosusBulbospongiosusSuperficial transverse perineus3 Muscles found just deep to the skinIschiocavernosus = arises from ischial & pubic ramusBulbospongiosus = covers bulb of penis or encloses vaginaSuperficial transverse perineus = extends from the ischial tuberosities to the central tendon of the perineumFunction during sexual intercourse & voiding of urine
68Muscles of the UG diaphragm Urogenital diaphragmExternal anal sphincterMiddle layer of pelvic floor contains Urogenital diaphragm and External anal sphincterUrogenital diaphragm = 2 musclesdeep transverse perineus m. supports pelvic visceraexternal urethral sphincter m. inhibits urination
69Muscles of the Pelvic Diaphragm Levator aniCoccygeusDeepest compartment of the perineumPelvic diaphragm = 2 muscleslevator ani m. supports viscera & functions during defecationcoccygeus m. supports and elevates pelvic floor
70HerniasProtrusion of viscera through muscular wall of abdominopelvic cavityInguinal herniamost common type of hernia (rare in women)viscera enter inguinal canal or even the scrotumHiatal herniastomach protrudes through diaphragm into thoraxoverweight people over 40Umbilical herniaviscera protrude through the navel
71Muscles Acting on the Pectoral Girdle Originate on axial skeleton & insert onto clavicle or scapulaAnterior muscle group = 2 musclesPosterior muscle group = 4 musclesScapular movements produced includemedial and lateral rotation of the scapulaelevation and depression of the scapulaprotraction and retraction of the scapulaClavicle braces the shoulder & limits movement
72Anterior Scapular Muscle Group Pectoralis Minorribs 3-5 to coracoid process of scapulaprotracts & depresses scapulalifts ribs during forced expirationSerratus Anteriorribs 1-9 to medial border of scapulaabducts & rotates or depresses scapulathrowing muscle
75Posterior Scapular Muscle Group Rhomboideus mm.medial border of scapula to C7-T1Levator scapulaefrom superior angle of scapula to C1-C4
76Muscles Acting on the Humerus 9 Muscles cross the shoulder joint to the humerus2 axial muscles arise from axial skeletonprime movers of humerus in flexion & extensionarise from sternum & clavicle OR T7-L5 & iliumPectoralis majorLatissimus dorsi
77Muscles Acting on the Humerus 7 scapular muscles arise from scapulaDeltoid is prime moverflexion, extension and abduction of humerusCoracobrachialis assists in flexionTeres major assists in extensionRemaining 4 form the rotator cuff muscles that reinforce the shoulder joint capsule
79Rotator Cuff Muscles Extending from posterior scapula to humerus supraspinatusinfraspinatusteres MinorSubscapularisSupraspinatusInfraspinatusExtending from anterior scapula to humerussubscapularisTeres minorAll 4 help reinforce joint capsule.
83Supination & Pronation of the Forearm Supinator musclePalm facing anteriorlyPronationPronator teres and Pronator quadratus mm.Palm faces posteriorly
84Muscles of the Anterior Forearm Flex/extend wrist and fingers, adduct/abduct wristDigitorum = inserts into fingersCarpi = inserts onto carpal bonesPollicis = inserts into thumb
85Muscles of the Posterior Forearm Extension of wrist and fingers, Adduct/abduct wristExtension and abduction of thumb (pollicis)Brevis = short, Ulnaris = on ulna side of forearmExtensors
86Intrinsic Hand Muscles Thenar group = fleshy base of thumb musclesHypothenar group = base of little finger musclesMidpalmar group = Interosseus mm. & Lumbrical mm.LumbricalInterosseus
87Carpal Tunnel Syndrome repetitive motions causes inflammation and pressure on median nerve
88Anterior Muscles Acting on the Hip Iliopsoas musclecrosses anterior surface of hip joint & inserts on femuriliacus portion arises from iliac fossapsoas portion arises from lumbar vertebraemajor hip flexorIliopsoas
89Posterior Muscles Acting on the Hip Gluteus mediusGluteus maximusforms mass of the buttockprime hip extensorprovides most of lift when you climb stairsIliotibial bandband of fascia lata attached to the tibiaGluteus maximusIliotibial band
90Deep Gluteal Muscles Gluteus minimus Piriformis Quadratus femoris Most laterally rotate femurExcept: Gluteus minimus medially rotates femurImportant in walking to shift body weight when foot is liftedQuadratus femoris is adductor of hipPiriformis & Gluteus minimus are abductors of hip
91Adductors of the Hip Joint 5 muscles act as adductorsAdductor magnus is also an extensor of hip jointGracilis also is flexor of kneePectineus, Adductor brevis and Adductor longus adduct the femurPectineusAdductor brevisAdductor longusAdductor magnus
92Muscles Acting on the Knee 4 headed muscle attaches to tibial tuberosityextends knee jointrectus femoris arises from ilium so flexes hip jointquadriceps femoris tendon attaches to patellapatellar ligament attaches to tibia
94Muscles of the Leg Crural muscles are separated into 3 compartments. anterior compartment (green)fibular (lateral) compartment (blue)posterior (superficial = brown) (deep = purple)
95Anterior Compartment of the Leg Extensor digitorum longusTibialis anteriorPeroneus tertiusExtensor hallucis longusExtensor digitorum longus = extension of toes & ankleExtensor hallucis longus = extension of big toe & ankleFibularis tertius = dorsiflexes and everts footTibialis anterior = dorsiflexes and inverts foot
96Posterior Compartment of the Leg Superficial Group of Plantar Flexors PlantarisGastrocnemiusSoleusGastrocnemius = flexes knee and plantar flexes ankleSoleus = plantar flexes anklePlantaris = flexes knee and plantar flexes ankle
97Posterior Compartment of the Leg Deep Group of Plantar Flexors Tibialis posterior, Flexor digitorum longus, and Flexor hallucis longus and are plantar flexors.Popliteus unlocks the knee joint for knee flexion.
98Lateral Compartment of the Leg 2 muscles in this compartmentBoth plantar flex and evert the footProvides lift and forward thrustFibularis longusFibularis brevis
100Intrinsic Muscles of the Sole Four muscle layersSupport for the archesabduct & adduct the toesflex the toesOne dorsal muscleextensor digitorum brevis extends toesDorsal view
101Athletic Injuries Vulnerable to sudden and intense stress Proper conditioning and warm-up is neededCommon injuriesshinsplintspulled hamstringstennis elbowTreat initially with rest, ice, compression and elevation“No pain, no gain” is a dangerous misconception.