movement posture stabilize joints generate heat
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Skeletal System
Muscular SystemWhat is the purpose of muscle?MovementPostureStabilize jointsGenerate heatTypes of MuscleCompare all three muscle types.Look at:Location/number of nucleiAssociated structuresWhat controls the muscle contraction?
You should be able to answer the Practice questions on page 301when finished.Skeletal Muscle
Smooth Muscle
Cardiac Muscle
Skeletal MuscleStructure of Skeletal MuscleMuscle (wrapped in fascia, epimysium) Fascicles (bundles of muscle fibers, wrapped in perimysium) Muscle Fibers (cells, wrapped in endomysium)
Myofibrils
FilamentsStructure of Skeletal Muscle
Skeletal Muscle FibersSkeletal muscle fiber = single muscle cellMultinucleatedStriatedMyofibrils: myosin (thick filaments) and actin (thin filaments)Myosin and actin alternate forming striations (light and dark areas)Skeletal Muscle FibersSarcomeres pattern of actin/myosin alternating throughout muscle fiberContractile unit of muscleSarcolemma cell membrane of muscle cellsSarcoplasm cytoplasm of muscle cells
Muscle Videohttp://www.youtube.com/watch?v=EdHzKYDxrKc Gross Muscle Anatomy
Muscle
Epimysium
Endomysium
Perimysium
Fascicle
Muscle fiber/cell
Myofibrils
Sarcolemma
Sarcoplasm
Skeletal Muscle Layout
Actin
Myosin
Z line
I band
A band
H zone
Sarcomere
Sarcoplasmic ReticulumMuscle Filaments (Myofibrils)Myosin: composed of many myosin fibersHeads and tailsForms cross-bridge with actinHeads of myosin come in contact with actin during muscle contractionActin: double strands twisted into a helixTroponin wraps around actinTropomyosin contact point for myosinMuscle Filaments: Actin
Troponin
Tropomyosin
Thin filamentMuscle Filaments: Myosin
Heads
Tails
Thick filamentSarcoplasmic ReticulumCorresponds with the endoplasmic reticulum in other cells
CisternaeEnlarged portions of SR on either side of the T tubuleTransverse tubules (T tubules)Extends into sarcoplasm, contains extracellular fluidSarcoplasmic Reticulum
T tubule
Sarcoplasmic reticulum
Sarcomere
Myosin
Actin
Sarcolemma
Mitochondria
MyofibrilSkeletal Muscle ContractionMuscle ContractionOccurs when thin and thick filaments slide past one anotherShortens sarcomeres/whole muscle cell
Stimulated by neuronsNeuromuscular JunctionMotor neurons control skeletal muscle
Neuromuscular junction: where nerve cell synapses with the muscleMotor end plate: specialized part of muscle to receive neural signals (higher amount of mitochondria, nuclei/SR)One motor neuron can innervate many muscle cellsMotor unit: neuron AND the muscle(s) it controls
Neuromuscular JunctionSynaptic CleftSeparation between the neuron and the muscleNerve fiber releases synaptic vesicles containing neurotransmitters into the synaptic cleftNeurotransmitter for Skeletal Muscle ContractionAcetylcholine (ACh)Increases membrane permeability to sodiumSodium influx causes muscle impulse which transmits the contraction along the muscleThrough the sarcoplasmic reticulum, cisternae, T tubulesSliding Filament TheorySarcomeres shorten through movement of actin and myosin sliding past one another, not shortening themselvesH zone, A bands narrowZ lines come closer togetherNeeds ATP (energy), Ca2+Sliding Filament Theoryhttp://www.youtube.com/watch?v=Vlchs4omFDM Summarize the contraction cycle in your textbooks (pg. 292)
Summarize relaxationWhat enzyme is needed? What does this enzyme do?When ACh breaks down, what happens?
Sliding Filament TheoryMyoglobinCellular respiration is critical in muscle contraction
Myoglobin stores oxygen in muscle cellsGives muscle the reddish/brown colorSimilar to what other molecule?
Anaerobic ThresholdLactic acid thresholdMuscle forms lactic acid in absence of oxygenAnaerobic respiration
Muscle FatigueLoss of ability to contractCaused by: decrease in blood flow, ion imbalances, accumulation of lactic acid in muscle tissue
Cramps: sustained contraction of muscleChanges in extracellular matrix of muscle causes extended contractionHeat ProductionMuscle is a major source of body heatBlood transfers heat throughout body
Fast Twitch vs. Slow Twitch MusclesUse your textbook to compare and contrast fast twitch and slow twitch muscles
Give some examples for the ideal muscle types for different activitiesUse human and animals in your answer.Major Skeletal MusclesRemembering Muscle Nameshttp://www.youtube.com/watch?v=bUnzlkZGkvM
Muscles of the Headhttp://www.gwc.maricopa.edu/class/bio201/head/head1b.htm
Muscles of facial expressionMuscles of mastication
Muscles of Facial ExpressionEpicraniusFrontalisTemporalis Orbicularis occuliOrbicularis orisBuccinator
Muscles of Facial Expression
Muscles of MasticationMasseter elevates mandibleTemporalis elevates mandibleMuscles of the NeckSternocleidomastoid pulls head to one side, flexes neck, elevates sternum
Muscles of Mastication
Muscles of the Pectoral GirdleTrapezius rotates scapula, pull scapula (raise, medial, downward)Rhomboid major connects scapula with vertebraeRhomboid minor smaller than rhomboid major, connects scapula with vertebraeLevator scapulae elevates scapula
Muscles of Pectoral Girdle
Muscles of the Pectoral Girdle
Levator scapulaeTrapeziusRhomboid major and minor(external oblique)(Latissimus dorsi)(Deltoid)Before we can discuss the movement of the armBefore we can discuss the movement of the armWe need to get into the muscle actions:Flexor flexion bend at joint so angle between two parts gets closer togetherExtensor extension straightening joint so angle between two parts increasesAbductors abduction movement away from the midlineAdductors adduction movement toward the midlineRotators movement around an axis Muscles that move the Upper ArmPosterior: http://www.gwc.maricopa.edu/class/bio201/muscle/musc14.htm
Anterior: http://www.gwc.maricopa.edu/class/bio201/muscle/musc13.htmShoulder MusclesPosterior Shoulder:http://www.gwc.maricopa.edu/class/bio201/muscle/arm/shldrp.htm
Anterior Shoulder:http://www.gwc.maricopa.edu/class/bio201/muscle/arm/shldra.htm
Flexors that move the upper armCoracobrachialisScapula to middle of humerusFlexes and adducts armPectoralis majorThick muscle of upper chestFlexes, adducts, rotates arm medially
Extensors that move the upper armTeres majorScapula to the humerusAdduct and rotate arm mediallyLatissiums dorsi From middle of the back, around the side of your body and into the armpitExtend, adduct, rotate arm mediallyPull shoulder downward
Abductors that move the upper armDeltoidThick, triangular muscle that covers the shoulder jointConnects clavicle and scapula to the lateral side of the humerusAbducts arm
Rotators that move the upper armSubscapularisAnterior surface of scapulaConnects scapula and humerusRotate arm mediallyTeres minorScapula to humerusRotates arm laterally
Muscles that move the ForearmBiceps brachii
Triceps brachii
HandExtensor carpi radialis longusExtensor carpi radialis brevis
Both extend wrist, abduct hand
HandExtensor carpi ulnarisExtends wrist, adducts hand
Extensor digitorumExtends fingers
Flexor carpi radialis flexes wrist, abducts handFlexor carpi ulnaris flexes wrist, adducts hand
AbdomenRectus abdominus creates 6-packExternal oblique outermost layer, wraps around to the back of the bodyTransversus abdominus between external and internal obliqueInternal oblique within external oblique
Linea alba: band of tough connective tissue down medial line of abdomenMuscles of the Trunk
DeltoidPectoralis majorBiceps brachiiRectus abdominusTransversus abdominusInternal obliqueExternal obliqueMuscles that move the ThighGluteus maximusGluteus mediusGluteus minimus
Muscles that move the thighTensor fasciae lataeConnects ilium to lateral portion of thigh
Muscles that move the Leghttp://www.gwc.maricopa.edu/class/bio201/muscle/leg1.htm Muscles that move the legHamstring muscles:Biceps femoris (most lateral)Semitendonosis (middle)Semimembranosus (most medial)
Muscles that move the legSartorius hip to most distal, medial portion of the femur (medial portion of knee)
Muscles that move the legQuadriceps femoris group:Rectus femoris Vastus lateralisVastus medialis
Patellar tendon
Muscles that move the FootTibialis anterior
Gastrocnemius
Soleus
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