MuscularMuscular SystemSystemMade up of organsMade up of organs– MusclesMuscles

Remember organs are made up of tissueRemember organs are made up of tissue– Primarily skeletal muscle tissue, nervous Primarily skeletal muscle tissue, nervous

tissue and blood and other connective tissuestissue and blood and other connective tissues

And tissue is made up of cellsAnd tissue is made up of cells– composed of specialized cells that use the composed of specialized cells that use the

chemical energy stored in nutrients to exert a chemical energy stored in nutrients to exert a pulling force on structures to which they are pulling force on structures to which they are attached.attached.

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SkeletalSkeletal

SmoothSmooth

SkeletalSkeletal

CardiacCardiac

Muscle Cell CharacteristicsMuscle Cell CharacteristicsSmooth MuscleSmooth Muscle

InvoluntaryInvoluntarySurrounding walls Surrounding walls of hollow organs of hollow organs and glandsand glandsSpindle shapedSpindle shapedNot striatedNot striatedSingle nucleusSingle nucleusCentral nucleusCentral nucleusGap JunctionsGap JunctionsSingle and Multi-Single and Multi-unitunit

Muscle Cell CharacteristicsMuscle Cell CharacteristicsSkeletalSkeletal

VoluntaryVoluntaryAttached to bonesAttached to bonesCylindricalCylindricalStriatedStriatedMulti-nucleatedMulti-nucleatedNuclei near Nuclei near membranemembraneTight JunctionsTight JunctionsForm Motor UnitsForm Motor Units

CardiacCardiacInvoluntaryInvoluntaryHeartHeartCylindrical/BranchedCylindrical/BranchedStriatedStriatedSingle NucleusSingle NucleusCentral NucleusCentral NucleusGap Junctions – Gap Junctions – intercalated discsintercalated discsFigure 8 shapedFigure 8 shapedPacemakerPacemaker

FunctionsFunctions

Voluntary Movement – walking, Voluntary Movement – walking, talking, breathing, smiling (skeletal)talking, breathing, smiling (skeletal)

Provide muscle tone (skeletal)Provide muscle tone (skeletal)

Maintain posture (skeletal)Maintain posture (skeletal)

Propel body fluids and food Propel body fluids and food (smooth)(smooth)

Distributes heat (smooth)Distributes heat (smooth)

Generate heart beat (cardiac)Generate heart beat (cardiac)

Muscular SystemMuscular SystemThe muscular system consists of The muscular system consists of skeletal muscles skeletal muscles and their associated connective tissues. and their associated connective tissues. – It does not include cardiac muscle and smooth It does not include cardiac muscle and smooth

muscle, which are associated with muscle, which are associated with cardiovascular, digestive, urinary, etc.cardiovascular, digestive, urinary, etc.

Individual skeletal muscle is separated from Individual skeletal muscle is separated from adjacent muscles by dense connective tissue adjacent muscles by dense connective tissue (facia); projects beyond the ends to form a (facia); projects beyond the ends to form a tendon which intertwine with the periosteum of a tendon which intertwine with the periosteum of a bone, attaching the twobone, attaching the two– Tendinitis – Tendinitis –

inflamed from repeated stressinflamed from repeated stress

Whole Muscle AnatomyWhole Muscle AnatomyFasciaFascia – dense connective tissue – dense connective tissue separating adjacent musclesseparating adjacent muscles

TendonTendon – facia that projects beyond the – facia that projects beyond the ends of its muscle fibers, forming a ends of its muscle fibers, forming a cordlike extension to connect the muscle cordlike extension to connect the muscle to a boneto a bone

Whole Muscle AnatomyWhole Muscle AnatomyEpimysiumEpimysium – connect. tissue that encircles – connect. tissue that encircles all the fascicles to form a complete all the fascicles to form a complete muscle. muscle.

PerimysiumPerimysium – connect. tissue that – connect. tissue that encircles a group of muscle fibers, forming encircles a group of muscle fibers, forming a a fasciclefascicle. .

EndomysiumEndomysium - connective tissue that - connective tissue that surrounds each surrounds each muscle fiber (myofiber-muscle fiber (myofiber-cell). cell).

Fasicle

(Myofiber)Wrapped in Endomysium

(Actin & Myosin)

Perimysium

Perimysium

Epimysium

Muscle Cell AnatomyMuscle Cell AnatomyMyofiberMyofiber – muscle cell – muscle cell

Should be “myocyte”Should be “myocyte”

Prefix myo = muscle and suffix cyte Prefix myo = muscle and suffix cyte = cell= cell

*Cylindrical*Multi nucleated*Striated

Muscle Cell AnatomyMuscle Cell AnatomySarcolemmaSarcolemma – specialized cell membrane of – specialized cell membrane of muscle cell (actively transports Namuscle cell (actively transports Na++ and K and K++))

SarcoplasmSarcoplasm – cytoplasm of muscle cells (contains – cytoplasm of muscle cells (contains most mitochondria of any cell and oval nuclei)most mitochondria of any cell and oval nuclei)

Muscle Cell AnatomyMuscle Cell AnatomySarcoplasmic Reticulum (SR)Sarcoplasmic Reticulum (SR)– – specialized SER for specialized SER for storing and releasing and actively transporting storing and releasing and actively transporting calcium Cacalcium Ca++ ++

Transverse Tubules (T-tubules)Transverse Tubules (T-tubules)– – special passages special passages for Na+ that pass over SRfor Na+ that pass over SR

Muscle Cell AnatomyMuscle Cell AnatomyMyofibrilsMyofibrils – cylindrical organelles that – cylindrical organelles that contain the myofilaments needed for contain the myofilaments needed for muscle contractionmuscle contraction

MyofilamentsMyofilaments – protein fibers – protein fibersThin filaments – Thin filaments – actinactinThick filaments – Thick filaments – myosinmyosin

Muscle Cell AnatomyMuscle Cell AnatomySarcomereSarcomere – functional unit of contraction; – functional unit of contraction; a section of a myofibrila section of a myofibril– The organization of actin and myosin filaments that The organization of actin and myosin filaments that

make up a myofibril produce the alternating light and make up a myofibril produce the alternating light and dark striations characteristic of skeletal muscle (and dark striations characteristic of skeletal muscle (and cardiac muscle)cardiac muscle)

– The striations form a repeating pattern of units called The striations form a repeating pattern of units called sarcomeres.sarcomeres.

Sarcomere AnatomySarcomere AnatomyZ Line Z Line – membrane that marks the end of – membrane that marks the end of the sarcomere – actin is attached herethe sarcomere – actin is attached hereI band I band – at edges of sarcomere – light band – at edges of sarcomere – light band – contains only actin– contains only actinA Band A Band – Dark part of sarcomere – contain – Dark part of sarcomere – contain myosin (some parts have overlapping actin)myosin (some parts have overlapping actin)

Sarcomere AnatomySarcomere AnatomyH zone H zone – very center of A band – a little – very center of A band – a little lighter than rest of A band since only lighter than rest of A band since only contain myosin – no overlapping actincontain myosin – no overlapping actinM line M line – thickening in the center of the – thickening in the center of the sarcomere, proteins that hold myosin in sarcomere, proteins that hold myosin in placeplace

Muscle Innervation (Stimulation)Muscle Innervation (Stimulation)Motor Unit Motor Unit – One nerve connected to brain – One nerve connected to brain or spinal cord and all of the muscle cells/ or spinal cord and all of the muscle cells/ fibers that it innervates (stimulates)fibers that it innervates (stimulates)

All or None PrincipleAll or None PrincipleAll or None Principle All or None Principle – when you contract a motor unit, – when you contract a motor unit, every fiber or cell in the motor unit contracts and each every fiber or cell in the motor unit contracts and each contracts to the fullest extentcontracts to the fullest extent

How can you get different strengths of contraction in the How can you get different strengths of contraction in the same muscle?same muscle?– # OF MOTOR UNITS ACTIVATED!# OF MOTOR UNITS ACTIVATED!– Recruitment – multiple motor units stimulated for Recruitment – multiple motor units stimulated for

increased contractionincreased contraction– Precise movement - less motor units recruited (less Precise movement - less motor units recruited (less

cells) Ex. Eye movementcells) Ex. Eye movement– Gross movement - more motor units recruited (more Gross movement - more motor units recruited (more

cells) Ex. Quadricepscells) Ex. Quadriceps

*Remember skeletal muscles have voluntary control.*Remember skeletal muscles have voluntary control.

Skeletal Muscle ContractionSkeletal Muscle ContractionA contraction is movement within the A contraction is movement within the myofibrils, actin & myosin slide past one myofibrils, actin & myosin slide past one another; sarcomere shortensanother; sarcomere shortens

In order for a muscle cell to contract, it In order for a muscle cell to contract, it must be stimulated by a neuron.must be stimulated by a neuron.

NeuromuscularNeuromuscular junctionjunction – “communication – “communication site” where a motor neuron (part of a site” where a motor neuron (part of a motor unit) meets a muscle cell and motor unit) meets a muscle cell and stimulates it.stimulates it.

Neuromuscular JunctionNeuromuscular JunctionSarcolemmaSarcolemma – cell membrane – cell membraneMotor end plate Motor end plate – specialized folded region – specialized folded region of sarcolemma with neurotransmitter of sarcolemma with neurotransmitter receptorsreceptorsAxonAxon – cytoplasmic extension of the nerve – cytoplasmic extension of the nerve cell that meets the musclecell that meets the muscle

Neuromuscular JunctionNeuromuscular JunctionNeurotransmitter Neurotransmitter – chemical that allows – chemical that allows neuron to communicate will cellneuron to communicate will cell– AcetylcholineAcetylcholine (Ach) (Ach) – neurotransmitter that – neurotransmitter that

sets off contractionsets off contractionSynapticSynaptic vesiclevesicle – contains acetylcholine – contains acetylcholineSynapticSynaptic cleft (synapse) cleft (synapse) – part where – part where muscle membrane meets the nerve (do muscle membrane meets the nerve (do not actually touch), space where not actually touch), space where information passes (where Ach is dumped)information passes (where Ach is dumped)

Neuromuscular JunctionNeuromuscular JunctionT-TubuleT-Tubule – Ach binds to receptors on motor – Ach binds to receptors on motor end plate, opens T-tubule channels and end plate, opens T-tubule channels and allows Na+ to flow into cellallows Na+ to flow into cell

Terminal cisternae Terminal cisternae – specialized region of – specialized region of the SR that serve as a reservoir for Cathe SR that serve as a reservoir for Ca++++

Components of Muscle ContractionComponents of Muscle ContractionMyosinMyosin – thick filament that pulls actin in – thick filament that pulls actin in towards center of sarcomere to cause towards center of sarcomere to cause contractioncontraction– Cross-bridgesCross-bridges – globular part of myosin that – globular part of myosin that

projects outward and attaches to actinprojects outward and attaches to actin

ActinActin – thin filament with binding sites for – thin filament with binding sites for myosinmyosin

Components of Muscle ContractionComponents of Muscle Contraction

TropomyosinTropomyosin – a rope like protein that – a rope like protein that wraps around actin covering the active wraps around actin covering the active sites on actin so that myosin can’t bind to sites on actin so that myosin can’t bind to the actin (muscle relaxed)the actin (muscle relaxed)

Components of Muscle ContractionComponents of Muscle ContractionTroponinTroponin – small proteins that attach to – small proteins that attach to the tropomyosin– has a Cathe tropomyosin– has a Ca++ ++ binding site – binding site – when Cawhen Ca++++ binds it changes shape and in binds it changes shape and in turn causes the tropomyosin to swivel off turn causes the tropomyosin to swivel off of the active sites on actinof the active sites on actin

Skeletal Muscle ContractionSkeletal Muscle Contraction

A muscle fiber contraction is a result of A muscle fiber contraction is a result of a chain reaction of complex interactions a chain reaction of complex interactions between several cells and chemicals.between several cells and chemicals.– The chain reaction results in movement The chain reaction results in movement

within the myofibrils.within the myofibrils.– Actin and myosin slide past one another, Actin and myosin slide past one another,

shortening the sarcomere.shortening the sarcomere.– This causes the entire muscle fiber to This causes the entire muscle fiber to

shorten and pull on its attachments (bones) shorten and pull on its attachments (bones) to cause movement.to cause movement.

Steps of ContractionSteps of ContractionAch is released from the axon into the Ach is released from the axon into the synaptic cleft due to stimulation by nerve synaptic cleft due to stimulation by nerve impulse (the brain)impulse (the brain)– Reminder: Ach is a neurotransmitter that motor Reminder: Ach is a neurotransmitter that motor

neurons use to control skeletal muscle contraction; neurons use to control skeletal muscle contraction; synthesized in cytoplasm of motor neuron and stored synthesized in cytoplasm of motor neuron and stored in synaptic vesiclein synaptic vesicle

Ach binds to receptors on the motor end Ach binds to receptors on the motor end plateplate

This opens the T tubules causing NaThis opens the T tubules causing Na++ to to flow in through the T-tubulesflow in through the T-tubules

Steps of ContractionSteps of ContractionNa+ flowing in through the T-tubules Na+ flowing in through the T-tubules causes channels in SR to open causes channels in SR to open releasing Careleasing Ca++++

CaCa++++ attaches to troponin causing it attaches to troponin causing it to change shapeto change shapeThe troponin shape change causes The troponin shape change causes the tropomyosin to swivel off of the the tropomyosin to swivel off of the actin active sitesactin active sitesATP activated myosin heads pop up ATP activated myosin heads pop up (cross bridge) and grab on to actin (cross bridge) and grab on to actin and swivel forward (power stroke) and swivel forward (power stroke) dragging the actin inwarddragging the actin inward

Steps of ContractionSteps of Contraction

Many myosin heads are popping up Many myosin heads are popping up and grabbing on all at once – they and grabbing on all at once – they are staggered so that some are are staggered so that some are always attachedalways attached

This continues as long as there is This continues as long as there is calcium present and ATP to power calcium present and ATP to power the process (usually don’t run out of the process (usually don’t run out of the ATP – that would be exhaustion)the ATP – that would be exhaustion)

What physically happens to the sarcomere during contraction?

I band disappears during contraction and so does the H zone as actin is pulled in over myosin

(all light areas because actin and myosin completely overlap)

How to Stop a Normal ContractionHow to Stop a Normal ContractionDestroy the AchDestroy the Ach

Pump out the NaPump out the Na++

Pump all of the CaPump all of the Ca++++ back into the SR back into the SR (active transport with the help of ATP)(active transport with the help of ATP)

ATP is also needed to disconnect head from ATP is also needed to disconnect head from actin (just as it was needed to make the actin (just as it was needed to make the attachment)attachment)

Basically the reverse of what triggers a Basically the reverse of what triggers a contraction. This is different from contraction. This is different from exhaustion (running out of ATP)exhaustion (running out of ATP)

Energy Usage (Muscle Metabolism)Energy Usage (Muscle Metabolism)In order for muscles to contract, ATP must be available in the In order for muscles to contract, ATP must be available in the muscle fiber. ATP is available from: muscle fiber. ATP is available from: – Glycogen stored in muscle cellGlycogen stored in muscle cell. Glycogen is broken down to . Glycogen is broken down to

release glucose release glucose ATP is then generated from glucose by CR ATP is then generated from glucose by CR in the mitochondria.in the mitochondria.

– Glucose and fatty acids obtained from the bloodstreamGlucose and fatty acids obtained from the bloodstream. . When energy requirements are high, glycogen stored in the When energy requirements are high, glycogen stored in the liver & fatty acids from fat stored in adipose cells & the liver liver & fatty acids from fat stored in adipose cells & the liver are released into the bloodstream are released into the bloodstream Glucose and fatty acids Glucose and fatty acids are then absorbed from the bloodstream by muscle cells are then absorbed from the bloodstream by muscle cells ATP is then generated by CR.ATP is then generated by CR.

– Creatine phosphateCreatine phosphate. A high-energy molecule stored in . A high-energy molecule stored in muscle cells muscle cells transfers its high-energy phosphate group to transfers its high-energy phosphate group to ADP to form ATP ADP to form ATP able to generate enough ATP to maintain able to generate enough ATP to maintain muscle contraction for about 15 seconds.muscle contraction for about 15 seconds.

Aerobic RespirationAerobic RespirationNeeds a lot of oxygen to turn glucose into ATPNeeds a lot of oxygen to turn glucose into ATPMakes 38 ATP/glucose – only efficient way to Makes 38 ATP/glucose – only efficient way to make enough ATP for sustained muscle make enough ATP for sustained muscle contractioncontractionMyoglobin – red protein in muscle that binds Myoglobin – red protein in muscle that binds oxygen and stores itoxygen and stores itWhy need oxygen?Why need oxygen?– Make ATP aerobicallyMake ATP aerobically– Reload myoglobinReload myoglobin– Replenish creatine phosphateReplenish creatine phosphate

Advantages: generates a large amount of ATP.Advantages: generates a large amount of ATP.

Disadvantages: relatively slow and requires Disadvantages: relatively slow and requires oxygen.oxygen.

Anaerobic RespirationAnaerobic RespirationIf your need for ATP is greater than you If your need for ATP is greater than you can supply the oxygen for (oxygen debt)can supply the oxygen for (oxygen debt)Anaerobic activities include anything that Anaerobic activities include anything that makes you breathe excessively heavy – makes you breathe excessively heavy – sign you’re not getting enough oxygensign you’re not getting enough oxygen– sprinting, swimming really fast, biking really sprinting, swimming really fast, biking really

fast, lifting really heavy weightsfast, lifting really heavy weights

Glycolysis and then Fermentation takes Glycolysis and then Fermentation takes over – only make 2 ATP/glucose and lactic over – only make 2 ATP/glucose and lactic acid builds up to lead to muscle fatigueacid builds up to lead to muscle fatigue

Anaerobic RespirationAnaerobic RespirationAdvantages: Anaerobic respiration is relatively Advantages: Anaerobic respiration is relatively rapid, and does not require oxygen.rapid, and does not require oxygen.

Disadvantages: Anaerobic respiration generates Disadvantages: Anaerobic respiration generates only two ATPs (can’t sustain life) and produces only two ATPs (can’t sustain life) and produces lactic acid which contributes to muscle fatigue. lactic acid which contributes to muscle fatigue. Can’t keep this process up very long (will run out of Can’t keep this process up very long (will run out of ATP). After exercise, the liver and muscles need to ATP). After exercise, the liver and muscles need to convert the lactic acid back to pyruvic acid. In convert the lactic acid back to pyruvic acid. In order to do that, a lot of the oxygen the body is order to do that, a lot of the oxygen the body is now taking in does the conversion instead of being now taking in does the conversion instead of being used elsewhere. This is known as “repaying the used elsewhere. This is known as “repaying the debt,” hence the term “oxygen debt.”debt,” hence the term “oxygen debt.”

Muscle Twitch(A single muscle contraction)

* Latent: Sodium pumped in

* Latent : Stimulus to triggers Ach to release

* Latent/Contraction: Calcium pumped in contraction

* Relaxation: Calcium pumped out•Relaxation/maintaining: •Sodium pumped out Ach breaks down relaxation

Muscle TwitchMuscle TwitchA single muscle contractionA single muscle contraction

Latent period Latent period – Ach is released, Na– Ach is released, Na+ + rushes rushes in, Cain, Ca++++ is released, active sites are is released, active sites are uncovered on actin, myosin binds to actinuncovered on actin, myosin binds to actinContraction periodContraction period – myosin is pulling actin – myosin is pulling actin inwardinwardRelaxation periodRelaxation period – Ca – Ca++++ is being sucked is being sucked up by the SR, tropomyosin is recovering up by the SR, tropomyosin is recovering active sites on actin, myosin can no longer active sites on actin, myosin can no longer bind to actin, Nabind to actin, Na++ is also pumped out and is also pumped out and Ach is destroyed in the synaptic cleftAch is destroyed in the synaptic cleft

Fast vs. Slow Twitch MusclesFast vs. Slow Twitch MusclesFast Twitch MusclesFast Twitch Muscles– Contract fasterContract faster– White/Little myoglobinWhite/Little myoglobin– Bigger SR/Faster Ca++ releaseBigger SR/Faster Ca++ release

Slow Twitch MusclesSlow Twitch Muscles– Take longer to contract but can sustain Take longer to contract but can sustain

the contractionthe contraction– Red/Lots of myoglobinRed/Lots of myoglobin– More mitochondriaMore mitochondria

Miscellaneous TermsMiscellaneous TermsIsotonic Muscle Contractions Isotonic Muscle Contractions – muscle shortens – force of – muscle shortens – force of muscle is greater than the loadmuscle is greater than the loadIsometricIsometric – muscle doesn’t shorten – force of load > – muscle doesn’t shorten – force of load > force of muscleforce of muscleMuscle Tone Muscle Tone – some motor units are contracted but not – some motor units are contracted but not enough to move the muscleenough to move the muscleHypertrophyHypertrophy – muscle cells increase in size by increasing – muscle cells increase in size by increasing the amount of actin and myosin, SR, and mitochondria the amount of actin and myosin, SR, and mitochondria due to stress on muscledue to stress on muscleAtrophyAtrophy – shrinkage of a muscle because each muscle – shrinkage of a muscle because each muscle cell gets smaller – loses actin and myosin due to disusecell gets smaller – loses actin and myosin due to disuseRigorRigor MortisMortis – after death, calcium leaks out of SR and – after death, calcium leaks out of SR and the troponin/tropomyosin complex is moved from actin the troponin/tropomyosin complex is moved from actin active sites – myosin binds but no ATP is being produced active sites – myosin binds but no ATP is being produced to unattach it so muscle becomes rigid – as tissue starts to unattach it so muscle becomes rigid – as tissue starts to break down and decay, it goes awayto break down and decay, it goes away

Cardiac MuscleCardiac MuscleNo neurons innervating cells, no motor units – No neurons innervating cells, no motor units – one pacemaker and then conductive protein one pacemaker and then conductive protein fibers to carry the impulse to other cardiac cellsfibers to carry the impulse to other cardiac cellsGap junctions (intercalated discs) cause ions to Gap junctions (intercalated discs) cause ions to flow from cell to cell to get a coordinated flow from cell to cell to get a coordinated contractioncontractionImpulse starts in atria and then travels through Impulse starts in atria and then travels through ventricles so atria contract and then ventriclesventricles so atria contract and then ventriclesThe cardiac muscle cells have the same The cardiac muscle cells have the same arrangement of actin and myosin (striations) but arrangement of actin and myosin (striations) but only have one nucleus and have bigger only have one nucleus and have bigger mitochondria and only 1 T-Tubulemitochondria and only 1 T-TubuleContracts slower – takes more time for calcium to Contracts slower – takes more time for calcium to diffusediffuseContracts about 70 times/min.Contracts about 70 times/min.Long Refractory period so there is no tetanus Long Refractory period so there is no tetanus even when the heart is beating fasteven when the heart is beating fast

Smooth MuscleSmooth Muscle

Contracts slower and longer (takes longer Contracts slower and longer (takes longer for Ca++ to diffuse and to be pumped for Ca++ to diffuse and to be pumped back into the SR)back into the SR)Actin and myosin different from cardiac Actin and myosin different from cardiac and skeletal – actin is attached to dense and skeletal – actin is attached to dense bodies and membrane but myosin still bodies and membrane but myosin still pulls it in – just pulls ii in every directionpulls it in – just pulls ii in every directionNo motor units – instead most are single No motor units – instead most are single unit junctions – a nerve synapses with one unit junctions – a nerve synapses with one smooth muscle cell and the impulse smooth muscle cell and the impulse spreads thru gap junctions so it all spreads thru gap junctions so it all contracts in a wavecontracts in a waveIn pupil – multi-unit – each smooth muscle In pupil – multi-unit – each smooth muscle cell has its own nervecell has its own nerve

Naming Muscles and Motions Naming Muscles and Motions Muscles MakeMuscles Make

Naming MusclesNaming Muscles

Anatomical location Anatomical location – muscles are – muscles are often named for their anatomical often named for their anatomical locationlocation– Ex: brachialis, coracobrachialis and Ex: brachialis, coracobrachialis and

brachioradialisbrachioradialis– Arm (brachial)Arm (brachial)– Ex: rectus femoris, biceps femorisEx: rectus femoris, biceps femoris– Femoral/FemurFemoral/Femur

Naming MusclesNaming MusclesOrigin and Insertion Origin and Insertion – originorigin - end of muscle that - end of muscle that

attaches to the stationary attaches to the stationary

structure (bone)structure (bone)– insertioninsertion - end of muscle that - end of muscle that

attaches to the moving structure (bone or skin)attaches to the moving structure (bone or skin)

XiphihumeralisXiphihumeralis– O: zyphoid process, I: humerusO: zyphoid process, I: humerus

ZygomaticusZygomaticus– O: zygomatic bone I: skin around mouthO: zygomatic bone I: skin around mouth

Naming Muscles ContinuedNaming Muscles Continued

Number of Origins Number of Origins – biceps brachii– biceps brachii

Shape of Muscle Shape of Muscle – – – deltoid – triangulardeltoid – triangular– trapezius – trapezoidtrapezius – trapezoid

Naming Muscles ContinuedNaming Muscles ContinuedRelative Size of the Muscles Relative Size of the Muscles - - Pectoralis major and minor, Gluteus Pectoralis major and minor, Gluteus maximus and minimusmaximus and minimus

Action of MuscleAction of Muscle - -

flexors, adductorsflexors, adductors

Movement of MusclesMovement of MusclesMovement is the result of a skeletal muscle Movement is the result of a skeletal muscle attached by tendons to one bone and extending attached by tendons to one bone and extending across a joint to attach to another bone; forming across a joint to attach to another bone; forming a a leverlever. A skeletal muscle can also attach to skin . A skeletal muscle can also attach to skin in the face. in the face. – OriginOrigin - end that attaches to the stationary structure, - end that attaches to the stationary structure,

usually a bone usually a bone – InsertionInsertion - end that attaches to the moving structure. - end that attaches to the moving structure. – BellyBelly - part of the muscle between the origin and - part of the muscle between the origin and

insertion.insertion.– ContractionContraction - insertion is pulled - insertion is pulled

toward origin toward origin

Motions Muscles MakeMotions Muscles MakeSeveral muscles usually influence a Several muscles usually influence a particular body movementparticular body movement– Prime Mover Prime Mover – main muscle for a motion; – main muscle for a motion;

contraction/shortening of a musclecontraction/shortening of a muscle– SynergistSynergist – muscles that helps or works with the – muscles that helps or works with the

prime mover to do a motionprime mover to do a motion– AntagonistAntagonist – muscle that does the opposite – muscle that does the opposite

motion or prime mover; relaxation/elongation of motion or prime mover; relaxation/elongation of musclemuscle

– Ex: flexing – prime is bicep, antagonist is tricepsEx: flexing – prime is bicep, antagonist is triceps

Motion Definition/Explanation

Examples

1.

15.

Motions Muscles Make

Resources – PowerPoint, p. 267-270 in textbook, p. 21 coloring book

Motions Muscles MakeMotions Muscles MakeFlexionFlexion – decreasing angle between – decreasing angle between two bones that meet at a joint, brings two bones that meet at a joint, brings bones closer togetherbones closer together

ExtensionExtension – increasing the angle in – increasing the angle in the joint (straightening), move bones the joint (straightening), move bones farther apartfarther apart

Motions Muscles MakeMotions Muscles Make

HyperextensionHyperextension – straightening more – straightening more than 180than 18000, extending beyond , extending beyond anotomical positonanotomical positon

Motions Muscles MakeMotions Muscles MakeAbductionAbduction – movement of a limb – movement of a limb away from the midline of the body; away from the midline of the body; spreading fingers or toesspreading fingers or toes

AdductionAdduction – movement of a limb – movement of a limb toward the midline; closing fingers or toward the midline; closing fingers or toestoes

Motions Muscles MakeMotions Muscles Make

RotationRotation – movement of a bone – movement of a bone around its axis (medial and lateral)around its axis (medial and lateral)

Motions Muscles MakeMotions Muscles MakeCircumductionCircumduction – movement of distal – movement of distal portion around stationary proximal portion around stationary proximal portion of the boneportion of the bone– Ex: fingers, leg, arm, head moving in Ex: fingers, leg, arm, head moving in

circular motioncircular motion

Motions Muscles MakeMotions Muscles MakePronationPronation – turning the palms down – turning the palms down (or facing posteriorly); special kind of (or facing posteriorly); special kind of rotation; radius in medial positionrotation; radius in medial positionSupinationSupination – turning the palms up (or – turning the palms up (or facing anteriorly); also a rotation; facing anteriorly); also a rotation; radius in lateral positionradius in lateral position

Motions Muscles MakeMotions Muscles Make

InversionInversion – turning the sole of the – turning the sole of the foot in (medial); supinatefoot in (medial); supinate

EversionEversion – turning the sole of the foot – turning the sole of the foot out (lateral); pronateout (lateral); pronate

Motions Muscles MakeMotions Muscles Make

DorsiflexionDorsiflexion – movement at ankle – movement at ankle pulling the toes up toward the tibia pulling the toes up toward the tibia (walking on heels)(walking on heels)

PlantarPlantar FlexionFlexion – movement at ankle – movement at ankle that move foot away from tibia that move foot away from tibia (pointing toes)(pointing toes)

Motions Muscles MakeMotions Muscles Make

ElevationElevation – raising a part (shrugging – raising a part (shrugging shoulders)shoulders)

DepressionDepression – lowering a part – lowering a part (drooping the shoulders)(drooping the shoulders)

Muscle IdentificationMuscle Identification

Face, Skull and Neck Muscle Face, Skull and Neck Muscle IdentificationIdentification

Face, Skull and Neck Muscle Face, Skull and Neck Muscle IdentificationIdentification

Not pictured:

DigastricsSternohyoidSternothyroid

Facial and Neck Muscle IdentificationFacial and Neck Muscle Identification

1.

2.

3.3. 4.

5.

Anterior TrunkAnterior Trunk

Human vs. Cat Pec MusclesHuman vs. Cat Pec Muscles

Abdominal Muscle IdentificationAbdominal Muscle Identification

Cat Abdominal MusclesCat Abdominal Muscles

Posterior TrunkPosterior TrunkHumans: have onelarge trapeziusmuscle.

Cats: havethree separate – ClavotrapeziusAcromiotrapezuis,Spinotrapezius,

Humans: have one large deltoid muscle

Cats: have three separate – ClavodeltoidAcromiodeltoidSpinodeltoid

Humans: GluteusMaximus, medius,& minimusCats: Gluteus Maximus (smaller)Medius (bigger) and Caudofemoralis

Leg Muscles - PosteriorLeg Muscles - Posterior

HamstringsHamstrings (back of (back of leg)leg)

Biceps femoris (main Biceps femoris (main hamstring/lateral side hamstring/lateral side of posterior leg)of posterior leg)

Semitendinosus Semitendinosus (towards medial side (towards medial side of posterior leg)of posterior leg)

Semimembranosus Semimembranosus (most medial – see (most medial – see best on anterior side)best on anterior side)

Leg Muscles - AnteriorLeg Muscles - Anterior

QuadricepsQuadriceps (front (front of leg)(quad=4)of leg)(quad=4)

Rectus femoris Rectus femoris (main quad)(main quad)

Vastus lateralisVastus lateralis

Vastus medialisVastus medialis

Vastus intermedius Vastus intermedius (smallest)(smallest)

Gluts Human vs. CatGluts Human vs. Cat

Anterior

Posterior

ReferencesReferences

http://www.cliffsnotes.com/http://www.cliffsnotes.com/study_guide/Skeletal-Muscle-study_guide/Skeletal-Muscle-Actions.topicArticleId-Actions.topicArticleId-277792,articleId-277601.html277792,articleId-277601.html