Smooth muscle ContractionSpindle ShapedCentral nucleiLack Striations, transverse tubules, and lack well developed sacroplasmic reticulumActin and myosin thin and randomly distributedMulti-unit-Separate unitsMuscle of iris and blood vesselsVisceral-Sheets of spindle cellsRespond as a single unitRhythmicity- spontaneousperistalsis

Internal organs-outer longitudinalInner circularContraction Impulses travel across the membrane- Calcium diffuses into the cell from the extracellular fluid. Calcium binds to a protein calmodulin-activating contraction.Nt- Ach and Norepi, stimulates/ inhibits contractions altering degrees of contraction.Smooth- slow and longer contraction

TermsOriginInsertionPrime mover-AgonistAssist a prime mover-SynergistsAntagonist- movement in the opposite direction or resist a prime mover,

Skeletal Muscle Actions origin immovable end insertion movable end prime mover (agonist) primarily responsible for movement synergists assist prime mover antagonist resist prime movers action and cause movement in the opposite direction

Muscular TissueThree Types of Muscle TissuesSkeletal Muscle usually attached to bones under conscious control striatedSmooth Muscle walls of most viscera, blood vessels, skin not under conscious control not striatedCardiac Muscle wall of heart not under conscious control striated

Smooth Muscle FibersCompared to skeletal muscle fibers shorter single nucleus elongated with tapering ends myofilaments randomly organized no striations lack transverse tubules sarcoplasmic reticula not well developed

Cardiac Muscle only in the heart muscle fibers joined together by intercalated discs fibers branch network of fibers contracts as a unit self-exciting and rhythmic longer refractory period than skeletal muscle

Muscles of Facial Expression-CNVIIOrbicularis oculi-blinking/closes eyelidsOrbicularis oris-closes lips/protrudes lips-kissingBuccinator-compresses cheeks as in blowing airZygomaticus-raises corner of mouth/smilingPlatysma-pouting/draws mouth downward & elevates skinFrontalis-elevates eyebrows & creases skin

Muscles of Mastication-CNV3Masseter-elevates mandibleTemporalis-elevates mandiblePterygoidMedial-elevates and moves it from side to sideLateral-depresses and protracts

Muscles of Head and VertebraPaired muscles- flex, extend, and rotate the head and hold the torso erect. Sternocleidomastoid-flex and rotatesExtend and rotateSplenius capitisSemispinalis capitisErector spinae

Muscle of the Pectoral GirdleTrapezius- raises scapula and shoulders, elevates clavicle, extends neck and headSerratus Anterior -pulls scapula forward and downward, used when pushing something.Damage to the long thoracic nerve-results in winged scapulaRhomboids-retracts, elevates, and rotatesLevator Scapula-elevates scapulaPectoralis minor- pulls scapula in forward and downward, raise ribs in forceful inhalation

Muscles That Move the ArmFlexorsCoracobrachialis Pectoralis major- also adducts arm

ExtensorsTeres Major Latissimus dorsi- also adducts arm (swimmer muscle)

AbductorsDeltoid most prominent muscle of the shoulder-axillary nerve-fracture to the neck of humerus-unable to abduct the armSupraspinatus

Rotators cuff musclesSubscapularisInfraspinatusTeres minorSupraspinatus

Movement of ForearmBiceps brachii-flexes and laterally rotates elbowBrachialis- strongest flexor of elbowBrachioradialis-aids in flexingTriceps- opposes-extends elbow

Muscle of the Abdominal areaCompress the abdominal cavity and increases pressure, used during forceful exhalation or defecationRectus abdominis-six packExternal oblique-fibers runs downward to pelvic girdleInternal oblique-fibers run upward to lower ribsTransversus abnominis- deepest layer-runs horizontally acrossLinea alba- connective tissue band that runs from xiphoid to symphysis pubis

Transversus abdnominis

Muscles of the ThighAnterior group- primary flexors of thighPsoasiliacusPosterior group- extends the thighGluteus muscles- maximus-the largest muscle in the bodyTensor fasciae latae-extends from ilium to the iliotibial tract- abducts, rotates, and flexes AdductorsPectineus-flexesAdductor brevis, longus, magnus-flex and rotateGracilis- straplike band from the pubic bone to tibia

Pectineus

Gluteus Muscle

Quadriceps Femoris groupExtensor

Extends leg at kneeRectus femorisVastus lateralisVastus medialisVastus intermedius

Flexors of kneeHamstring MusclesBiceps femorisSemimembranosusSemitendinosus

Sartorius-strap like that passes obliquely across the front of thigh- abducts and rotates laterally

SemitendinosusSemimembranosus