9CircumductionMovement of a limb or extremity so that the distal end describes a circle while the proximal end remains fixed
10Seven Golden Rules of Muscle Activity Muscles get smaller as they contract.Muscles cross at least one joint.The bulk of the muscle lies proximal to the joint crossed.All muscles have an insertion and origin.During contraction, the insertion moves toward the origin.Muscles only pull; they never push.Muscles work in pairs.
11Smaller as they Contract. 1.Muscles Get …..Smaller as they Contract.Try it with your bicep!!!
122.Muscles Cross at Least One Joint Think drawbridge!!How can muscles effect movement if they don’t cross a joint?Where does the bulk of the muscle lie?
15Muscle Attachment Sites: Origin & Insertion Skeletal muscles produce movements by exerting force on tendonsTendons pull on bones or other structures such as skinSkeletal muscle contraction pulls one articulating bone towards the otherOrigin (usually proximal): attachment of a muscle tendon to the stationary boneInsertion (usually distal): attachment of the muscle’s other tendon to the movable boneAction/s: main movements that occur when the muscle contracts
16All Muscles Have an Insertion and an Origin Insertion = More moveable attachmentOrigin = Less moveable attachmentInsertion is usually distal.Origin is usually proximal.Insertion moves toward origin during muscle contraction.
17Because they work in PAIRS!!!! Muscles Only PullSo how do they effect flexion AND extension? Abduction AND Adduction?Because they work in PAIRS!!!!Prime Mover = the muscle with major responsibility for effecting a movement.Antagonist = the opposing muscle responsible for the opposite movement.
18Naming the Skeletal Muscles Location: example the frontalis is located over frontal boneShape: example the deltoid (“triangular) is triangularRelative size: maximus, minimus, and longusExample: gluteus maximus and gluteus minimusDirection of fascicles and muscle fibers: direction that fibers runExample: rectus (straight or parallel) abdominis and transversus (perpendicular) abdominisLocation of attachments: reveals point of origin and insertionExample: sternocledomastoid = origin on sternum and clavicle with insertion on mastoidNumber of origins: two, three, or four originsIndicated by the words biceps, triceps, and quadricepsAction: part of the muscle’s name indicates muscle movementFlexor, extensor, adductor, or abductor
19BellworkWhat are two ways in which muscles are named? Give examples?
23Muscles of the Head—Facial Expression Figure 11.9
24Facial expression Frontalis Zygomaticus Origin: Cranial apneurosis Insertion: Skin of eyebrowsRaises eyebrows and wrinkles the skin of your foreheadZygomaticusOrigin: CheekboneInsertion: Corner of mouthExtends from corner of the mouth to the cheekboneSmiling and Laughing
25Muscles of the Head—Facial Expression Figure 11.9
26Facial Expression Orbicularis Oculi Orbicularis Oris Origin/Insertion: Around eye orbitalFibers that run in circles around the eyes. Allows your eyes, squint, blink, winkOrbicularis OrisOrigin/Insertion: Around lipsCircular muscle of lips.Closes the mouthKissing muscle
27Muscles of the Head—Facial Expression Figure 11.9
28Chewing Masseter Origin: Zygomatic Process Insertion: Mandible Covers the angle of the lower jaw as it runs from the zygomatic processCloses jaw by elevating jaw
35Trunk Muscles External Oblique Internal Oblique Both Origin: Last 8 ribs (External)Insertion: IliumInternal ObliqueOrigin: Iliac CrestInsertion: Last 3 ribs (Internal)BothFlex vertebral columnRotate trunk and bend it laterally
37Superficial Muscles of the Posterior Thorax Trapezius(c)LevatorscapulaeSupraspinatusClavicleSpine of scapulaInfraspinatusTeres minorHumerusDeltoidTeresmajorLatissimusdorsiRhomboidminorFigure 11.16c
38Superficial Muscles of the Posterior Thorax Levatorscapulae(d)RhomboidminormajorInfraspinatusTeres majorTeres minorLatissimusdorsiTrapeziusDeltoidTricepsbrachiiTriangle ofauscultationFigure 11.16d
39Posterior Muscles Latissimus dorsi Trapezius Covers lower back Origin: Lower SpineInsertion: Proximal end of humerusExtends, adducts and rotates the arm mediallySwimmer’s muscleTrapeziusKite shapedOrigin: Runs from skull down vertebral columnInsertion: scapular spine and clavicleExtends the head
40Posterior Muscles Deltoid Triangle-shaped Origin: clavicle Insertion: proximal humerusForm rounded shape of shouldersPrimary movers of arm abduction
48Posterior Muscles Gluteus maximus Origin: pelvis Insertion: femur Movement of Hip and Thigh in walking (Extends the thigh at the hip).Ex: Climbing stairs and standing upAlso helps abduct thighGluteus mediusGluteus maximusAdductor magnusGracilisIliotibial tractLong headSemitendinosusSemimembranosusShort headBiceps femoris(c)Figure 11.23c
49Posterior MusclesHamstring Group (Semitendinosus, Semimembranosus, Biceps femoris)Origin: IschiumInsertion: TibiaFlexes knee and extends the thigh at hip
50Anterior MusclesQuadriceps Group(Vastus Medialis, Intermedius and Lateralis and Rectus Femoris)Composed of four musclesOrigin: Femur/ PelvisInsertion: TibiaExtends knee and flexes thigh at hip
51Moving foot Gastrocnemius (calf muscle)- Origin: Femur Insertion: Calcaneusflexes foot and leg (at knee), supinates foot
53Muscles of the Posterior Compartment Superficial muscles: triceps surae (gastrocnemius, soleus) and the plantarisPlantarisTendon ofgastrocnemiusCalcanealtendonMedialmalleolusMedial headGastroc-nemiusLateral headLateralCalcaneus(a)SoleusTendon of tibialisposteriorTendon ofplantarisFibularis brevisHead of fibulaPopliteusPlantarisGastroc-nemiusLateral head(cut)Medial headFibularis longus(b)Figure 11.27a, b