Muscular System

Parts of a Muscle 1. Origin: Point of attachment that does not move when a muscle contracts- usually bone, can be another muscle. 2. Belly: main body- actually contracts 3. Insertion: point of attachment that moves when a muscle contracts.

Muscle Actions 1.Agonist (prime movers)- move body out of anatomical position (flexors, abductors) 2.Antagonists- move body back to original position 3.Fixators- stabilize other muscles

Naming Muscles 1. Location of the muscle: anterior, dorsi, oculi=eye, oris=mouth 2. Size and shape: maximus, minimis, lattismus= broad, trapezius (trapezoid), deltoid (delta) 3. Number of origins: biceps (2), triceps (3), quadraceps (4) 4. Origins/ Insertions: tibialis- tibia femoris- femur sternocleidomastoidus- origin- sternum and clavicle, insterion- mastoid process 5. Direction of fibers: Orbicularis – in an orbit, rectus- run with midline, oblique – angled to midline

Muscles of the Head and Neck

Muscle Name OriginInsertionAction FrontalisGalae Aponeurotia Skin/eyebrowsRaise eyebrows Orbicularis OculiFrontal MaxillaEyelidCloses eye Orbicularis OrisMaxilla Mandible LipsKissing muscle ZygomaticusZygomaticCorner of lipsSmile MentallisMandibleLower lipsProtrude lower lips (pout)

Muscle Name OriginInsertionAction BuccinatorMandible Maxilla LipsSucking muscle (innate) PlatysmaPectorallis MajorLower mandibleLowers jaw (to speak) MesseterZygomaticMandibleCloses jaw (to speak) TemporalisTemporalMandibleHolds jaw closed Pterygoids lateral mediallis internus Pterygoid plateMandibleSide to side rotational movement

Muscle Name OriginInsertionAction SternomastoidSternum/clavicleMastoid processLowers chin/rotates ear to chest, flexes head Semispinalis capitis Upper thoracic cervical Upper cervicalExtends head

Muscles of the Chest

Muscle Name OriginInsertionAction Pectorallis MajorClavical sternum ribs 1-6 HumerusPull arms forward Serratus anteriorRibs 1-9Under arms to scapula Boxer muscles- pulls arms forward and down Lattisimus dorsiThoracic vertebrae, lumbar vertebrae, illiac crest HumerusPulls arms down and back DeltoidClavicle/ scapulaHumerusRaises arms and shoulders (shrugs) TrapeziusCervical vertebrae Thoracic vertebrae Clavicle, scapulaRaises shoulders, pulls back shoulders

Muscle Name OriginInsertionAction Rectus Abdominus PubisLower ribs/sternum Flexes trunk (bend over) External oblique (on each side) RibsIlliac crestTogether- flex Separate- rotate Triceps BrachiScapula 1 head Humerus 2 heads Olecronon process of the ulna Extends elbow Biceps BrachiCorecoi process humerus RadiusFlex elbow Supinate forearm BrachioradiallisHumerusRadiusFlex and rotates forearms

Muscle Name OriginInsertionAction Flexor-carpi Radiallis HumerusMatacarpalsFlex wrist Flexor Digitorum superficialis Humerus/ulnaMiddle phalangies (2-5) Flex fingers Flexor Pollicus Longus RadiusThumbFlexes thumb inward to grasp Extensor Carpi Radialis Longus Humerus2 nd MetacarpalExtends wrist Extensor digitorum HumerusDistal phalangiesExtends fingers

Hips and Lower Appendages

Muscle Name OriginInsertionAction SartorisIlliac spineMedial tibia (crosses leg) Flex and rotate thigh, flex knee Biceps FemorisIllium femurFibula tibiaExtends thigh flexes knee Quadraceps Femoris Rectus femorisIlliac spinePatellaExtend knee Vastus laterallisTrochanter (femur) PatellaExtends knee

Muscle Name OriginInsertionAction Vastus mediallusLinea asperaPatellaExtends knee Vastus Intermedius Femur shaftPatellaExtends knee Gluteus MaximusIllium/ sacrum/ coccyx FemurExtends thigh and rotates out Gastrochemius (calf) Distal femurCalcaneusExtends foot by raising heel SoleusTibiaAchilles TendonExtends foot

Muscle Name OriginInsertionAction Tibiallis AnteriorTibiaTarsalsFlex foot Flextor digitorumTibiaDistal phalangesFlexes toe Extensor digitorum longus TibiaMiddle phalangesExtends toe