Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Macroscopic & Microscopic Structure of Muscular System

10,068 views

Published on

Introduction to Muscular System

Published in: Health & Medicine
  • Hello! I have searched hard to find a reliable and best research paper writing service and finally i got a good option for my needs as ⇒ www.WritePaper.info ⇐
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Yes you are right. There are many research paper writing services available now. But almost services are fake and illegal. Only a genuine service will treat their customer with quality research papers. ⇒ www.HelpWriting.net ⇐
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Hi there! I just wanted to share a list of sites that helped me a lot during my studies: .................................................................................................................................... www.EssayWrite.best - Write an essay .................................................................................................................................... www.LitReview.xyz - Summary of books .................................................................................................................................... www.Coursework.best - Online coursework .................................................................................................................................... www.Dissertations.me - proquest dissertations .................................................................................................................................... www.ReMovie.club - Movies reviews .................................................................................................................................... www.WebSlides.vip - Best powerpoint presentations .................................................................................................................................... www.WritePaper.info - Write a research paper .................................................................................................................................... www.EddyHelp.com - Homework help online .................................................................................................................................... www.MyResumeHelp.net - Professional resume writing service .................................................................................................................................. www.HelpWriting.net - Help with writing any papers ......................................................................................................................................... Save so as not to lose
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Don't forget another good way of simplifying your writing is using external resources (such as HelpWriting.net ). This will definitely make your life more easier
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Dating for everyone is here: ❤❤❤ http://bit.ly/36cXjBY ❤❤❤
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Macroscopic & Microscopic Structure of Muscular System

  1. 1. Macroscopic &Macroscopic & Microscopic ofMicroscopic of Muscular SystemMuscular System HERMIZAN HALIHANAFIAH
  2. 2. Lesson ObjectiveLesson Objective By the end of this 2 hours lecture, student will beBy the end of this 2 hours lecture, student will be able to:able to: 1.1. State the types of muscle tissuesState the types of muscle tissues 2.2. Explain the microscopic structure of skeletal musclesExplain the microscopic structure of skeletal muscles 3.3. Explain the structure and function of the tendonExplain the structure and function of the tendon 4.4. Explain microscopic structure of cardiac musclesExplain microscopic structure of cardiac muscles 5.5. Explain microscopic structure of smooth musclesExplain microscopic structure of smooth muscles 6.6. State the properties of musclesState the properties of muscles 7.7. State the functions of the muscular systemState the functions of the muscular system
  3. 3. IntroductionIntroduction  Movement of theMovement of the limbs, the heart andlimbs, the heart and other parts of theother parts of the body are made bybody are made by muscular system.muscular system.
  4. 4. Types of Muscle TissuesTypes of Muscle Tissues 3 types of muscular tissues:3 types of muscular tissues: 1.1. Skeletal muscle tissueSkeletal muscle tissue 2.2. Cardiac muscle tissueCardiac muscle tissue 3.3. Smooth muscle tissueSmooth muscle tissue
  5. 5. Microscopic Structure of SkeletalMicroscopic Structure of Skeletal Muscles TissueMuscles Tissue  Multinucleated cellsMultinucleated cells  Derived from myoblast precursor cells.Derived from myoblast precursor cells.  Three layers of connective tissue extend formThree layers of connective tissue extend form fascia to protect and strengthen skeletal muscles.fascia to protect and strengthen skeletal muscles.  Epimysium, perimysium and endomysium.Epimysium, perimysium and endomysium.
  6. 6.  Epimysium – outermost layer, encircle the entireEpimysium – outermost layer, encircle the entire muscles.muscles.  Perimysium – surround 10 – 100 or more fiber,Perimysium – surround 10 – 100 or more fiber, separate muscle fiber into bundles calledseparate muscle fiber into bundles called fascicles.fascicles.  Endomysium – inside the fascicle, separatingEndomysium – inside the fascicle, separating individual muscle fiber from one another.individual muscle fiber from one another. Microscopic StructureMicroscopic Structure
  7. 7. Microscopic StructureMicroscopic Structure
  8. 8.  Important component – skeletal muscle fiberImportant component – skeletal muscle fiber (muscle cells)(muscle cells)  Diameter – 10 – 100Diameter – 10 – 100 μμm , length about 10 cm –m , length about 10 cm – 30 cm30 cm  Develop from immature cells,Develop from immature cells, myoblastmyoblast  Each matured skeletal muscle fiber consist aEach matured skeletal muscle fiber consist a hundred or more nucleushundred or more nucleus (multinucleated).(multinucleated). Microscopic StructureMicroscopic Structure
  9. 9.  The multiple nuclei are located just beneath the plasmaThe multiple nuclei are located just beneath the plasma membrane of muscle cells calledmembrane of muscle cells called sarcolemmasarcolemma..  Thousand of tiny invagination of sarcolemma calledThousand of tiny invagination of sarcolemma called transverse (T) tubulestransverse (T) tubules, penetrate in from the surface, penetrate in from the surface towards the centre of each muscle fiber.towards the centre of each muscle fiber.  Within the sarcolemma is a cytoplasm of muscle fiberWithin the sarcolemma is a cytoplasm of muscle fiber calledcalled sarcoplasmsarcoplasm.. Microscopic StructureMicroscopic Structure
  10. 10.  Within the sarcoplasm consist substantial substance ;Within the sarcoplasm consist substantial substance ; glycogen and red colored protein calledglycogen and red colored protein called myoglobinmyoglobin..  ConsistConsist many mitochondriamany mitochondria – highly active muscles– highly active muscles  At high magnification, within the sarcoplasm containAt high magnification, within the sarcoplasm contain myofibrilsmyofibrils, the, the contractile organellecontractile organelle of skeletalof skeletal muscles.muscles.  Myofibrils is about 2Myofibrils is about 2 μμm in diameter and extend them in diameter and extend the entire length of a muscle fiber.entire length of a muscle fiber.  Make the entire skeletal muscle fiber appearMake the entire skeletal muscle fiber appear striated.striated. Microscopic StructureMicroscopic Structure
  11. 11.  A fluid filled system of membranous sacs called theA fluid filled system of membranous sacs called the sarcoplamic reticulum (SR)sarcoplamic reticulum (SR) encircle each myofibril.encircle each myofibril.  Dilated end sacs of the SR calledDilated end sacs of the SR called terminal cisternsterminal cisterns..  AA tranverse tubultranverse tubul andand two terminal cisternstwo terminal cisterns form aform a triadtriad..  In theIn the relaxedrelaxed muscle fiber, themuscle fiber, the SR stores Ca2+.SR stores Ca2+.  MusclesMuscles contractioncontraction occurred due tooccurred due to releasing Ca2+releasing Ca2+ from terminal cisterns of SRfrom terminal cisterns of SR.. Microscopic StructureMicroscopic Structure
  12. 12.  Within myofibrils are smaller structures calledWithin myofibrils are smaller structures called filaments (myofilaments).filaments (myofilaments).  2 types of filaments;2 types of filaments; thickthick andand thin filamentsthin filaments  Thick filamentsThick filaments – 16nm diameter, 1-2– 16nm diameter, 1-2 μμm longm long  Thin filamentsThin filaments –– 8 nm diameter, 1-28 nm diameter, 1-2 μμm longm long Microscopic StructureMicroscopic Structure
  13. 13. Myofibril StructureMyofibril Structure Thick FilamentThin Filament
  14. 14.  Both thick and thin filaments involved in theBoth thick and thin filaments involved in the contractile process.contractile process.  Overall there are two thin filaments for every thickOverall there are two thin filaments for every thick filament in the regions of filament overlap.filament in the regions of filament overlap.  Filaments in myofibrils arranged in compartment calledFilaments in myofibrils arranged in compartment called sarcomeres.sarcomeres.  Sarcomere is the basic functional units ofSarcomere is the basic functional units of myofibrilsmyofibrils.. Microscopic StructureMicroscopic Structure
  15. 15.  Components of the sarcomereComponents of the sarcomere 1.1. Z discsZ discs 2.2. A bandA band 3.3. I bandI band 4.4. H zoneH zone 5.5. M lineM line Microscopic StructureMicroscopic Structure
  16. 16. 1.1. Z discsZ discs  narrow, plated shaped regions of dense proteinnarrow, plated shaped regions of dense protein meterial that separate one sarcomere from themeterial that separate one sarcomere from the next.next. 2.2. A bandA band  The dark, middle part of sarcomere, extendThe dark, middle part of sarcomere, extend the entire length of thick filaments plusthe entire length of thick filaments plus overlap area between thick and thin filament.overlap area between thick and thin filament. Microscopic StructureMicroscopic Structure
  17. 17. 3.3. I bandI band  Lighter zone, contain the rest of thin filament but no thickLighter zone, contain the rest of thin filament but no thick filamentsfilaments 4.4. H zoneH zone  A narrow region in the center of each A band that containA narrow region in the center of each A band that contain only thick filament and no thin filament.only thick filament and no thin filament. 5.5. M lineM line  Region center of the H zone and contain protein that hold theRegion center of the H zone and contain protein that hold the thick filament together at the center of sarcomerethick filament together at the center of sarcomere Microscopic StructureMicroscopic Structure
  18. 18. Structure of the MyofibrilsStructure of the Myofibrils  Muscle proteinMuscle protein  Build up from three types of protein:Build up from three types of protein:  Contractile proteinContractile protein – generate– generate forceforce duringduring contractioncontraction  Regulatory proteinRegulatory protein – help switch the contraction– help switch the contraction process on and offprocess on and off  Structural proteinStructural protein – keep the thick and thin filament– keep the thick and thin filament in thein the proper alignmentproper alignment,, give elasticitygive elasticity andand extensibility characteristics to myofibril.extensibility characteristics to myofibril. Microscopic StructureMicroscopic Structure
  19. 19. Structure of the Myofibrils (continue)Structure of the Myofibrils (continue)  Contractile protein –Contractile protein – myosin and actinmyosin and actin  Regulatory protein –Regulatory protein – tropomyosin, troponintropomyosin, troponin  Structural protein – titin,Structural protein – titin, αα – actinin, myomesin,– actinin, myomesin, nebulin, and dystrophinnebulin, and dystrophin Microscopic StructureMicroscopic Structure
  20. 20.  The role of actin proteinThe role of actin protein Discovered byDiscovered by StraubStraub in 1942in 1942  Hugh Huxley and Allan HuxleyHugh Huxley and Allan Huxley 1954 has found that the1954 has found that the protein, myosin, contracting inprotein, myosin, contracting in the presence of calcium ionsthe presence of calcium ions  Found that skeletal musclesFound that skeletal muscles shortens during contraction andshortens during contraction and because the thick and thinbecause the thick and thin filaments slide past one another.filaments slide past one another.  So the model describing thisSo the model describing this process is known as theprocess is known as the slidingsliding filament mechanism.filament mechanism. Contraction & Relaxation of SkeletalContraction & Relaxation of Skeletal Muscles FiberMuscles Fiber
  21. 21. The Sliding Filament MechanismThe Sliding Filament Mechanism The structure of the Myosin proteinThe structure of the Myosin protein  Myosin fx as a motor protein in all types of muscleMyosin fx as a motor protein in all types of muscle tissuestissues  Converting the chemical energy in ATP to theConverting the chemical energy in ATP to the mechanical energy of motion or production of forcemechanical energy of motion or production of force  In skeletal system, aboutIn skeletal system, about 300 myosin molecules300 myosin molecules formform aa single thick filamentssingle thick filaments..  Each myosin molecule is shaped likeEach myosin molecule is shaped like two golf clubstwo golf clubs twisted together.twisted together.
  22. 22.  The myosin tail (twisted golf club handles)The myosin tail (twisted golf club handles) point towards M linepoint towards M line inin the center of sarcomere.the center of sarcomere.  Tails of neighboring myosin lie parallel to one another forming theTails of neighboring myosin lie parallel to one another forming the shaft of the thick filament.shaft of the thick filament.  The two projection of each myosin molecules (golf club heads) areThe two projection of each myosin molecules (golf club heads) are calledcalled myosin heads.myosin heads.  The heads project outward from the shaft in spiraling fashion andThe heads project outward from the shaft in spiraling fashion and extendingextending towards thin filaments.towards thin filaments. The Sliding Filament MechanismThe Sliding Filament Mechanism
  23. 23. The Structure Of the Actin ProteinThe Structure Of the Actin Protein  Thin filament is anchored byThin filament is anchored by Z discZ disc  Their main component ofTheir main component of thin filamentsthin filaments is theis the actinactin proteinprotein  Individual actin molecules join to form actin filamentIndividual actin molecules join to form actin filament that is twisted into helix.that is twisted into helix.  On each actin molecule is aOn each actin molecule is a myosin – binding site,myosin – binding site, where awhere a myosin head can attach.myosin head can attach. The Sliding Filament MechanismThe Sliding Filament Mechanism
  24. 24. The Structure of the Tropomyosin and TroponinThe Structure of the Tropomyosin and Troponin  Part of the thin filamentPart of the thin filament  Tropomyosin in form of strandsTropomyosin in form of strands covered the myosin-covered the myosin- binding site on actinbinding site on actin duringduring muscles relaxationmuscles relaxation, prevent, prevent attachment of myosin heads.attachment of myosin heads.  Tropomyosin are held in place byTropomyosin are held in place by troponintroponin..  Troponin also is aTroponin also is a binding site for Cabinding site for Ca2+,2+, causing musclescausing muscles contraction.contraction. The Sliding Filament MechanismThe Sliding Filament Mechanism
  25. 25. Thin FilamentsThin Filaments
  26. 26. The Contraction CycleThe Contraction Cycle  At the onset of contraction,At the onset of contraction, SR release CaSR release Ca2+2+ intointo cytosol.cytosol.  CaCa2+2+ will bind to troponin, causes tropomyosinwill bind to troponin, causes tropomyosin moves away from myosin-binding sites on actinmoves away from myosin-binding sites on actin..  Once myosin-binding sites are free, theOnce myosin-binding sites are free, the contraction cycle begin.contraction cycle begin. The Sliding Filament MechanismThe Sliding Filament Mechanism
  27. 27. 4 steps in Contraction Cycle4 steps in Contraction Cycle 1.1. ATP hydrolysisATP hydrolysis 2.2. Attachment of myosin to actin to formAttachment of myosin to actin to form crossbridges.crossbridges. 3.3. Power strokePower stroke 4.4. Detachment of myosin from actinDetachment of myosin from actin The Sliding Filament MechanismThe Sliding Filament Mechanism
  28. 28. ATP hydrolysisATP hydrolysis  Myosin heads hydrolize ATP into ADP andMyosin heads hydrolize ATP into ADP and Phosphate group.Phosphate group.  Myosin head become reoriented and energized.Myosin head become reoriented and energized.  ADP and phosphate group remain in the myosinADP and phosphate group remain in the myosin heads.heads. The Sliding Filament MechanismThe Sliding Filament Mechanism
  29. 29. Crossbridges formationCrossbridges formation  The myosin heads attaches to the myosin-binding siteThe myosin heads attaches to the myosin-binding site on actin forming crossbridges.on actin forming crossbridges.  Phosphate group releases from myosin head.Phosphate group releases from myosin head. The Sliding Filament MechanismThe Sliding Filament Mechanism
  30. 30. Power StrokePower Stroke  Energy stored in the myosin heads is used to move theEnergy stored in the myosin heads is used to move the myosin heads, causing the actin (thin filament) slidemyosin heads, causing the actin (thin filament) slide past the myosin (thick filament) towards M line.past the myosin (thick filament) towards M line. The Sliding Filament MechanismThe Sliding Filament Mechanism
  31. 31. Detachment of myosin from actinDetachment of myosin from actin  At the end of power stroke, the crossbridge firmlyAt the end of power stroke, the crossbridge firmly remain attached to the actin until it binds anotherremain attached to the actin until it binds another molecule ATP.molecule ATP.  As ATP bind to the ATP binding site on the myosinAs ATP bind to the ATP binding site on the myosin head, the myosin head detaches from actin.head, the myosin head detaches from actin. The Sliding Filament MechanismThe Sliding Filament Mechanism
  32. 32. Sliding Filament MechanismSliding Filament Mechanism
  33. 33. Sliding Filament MechanismSliding Filament Mechanism
  34. 34. Sliding Filament MechanismSliding Filament Mechanism
  35. 35. Sliding Filament MechanismSliding Filament Mechanism
  36. 36. Sliding Filament MechanismSliding Filament Mechanism
  37. 37. Sliding Filament MechanismSliding Filament Mechanism
  38. 38. TendonTendon  A cord of dense regular connective tissueA cord of dense regular connective tissue  Composed by parallel bundle of collagen fiberComposed by parallel bundle of collagen fiber  Attach muscles to the periosteum of the boneAttach muscles to the periosteum of the bone  For exp ; Achilles tendon connect gastrocnemiusFor exp ; Achilles tendon connect gastrocnemius muscles to the calcaneal bone.muscles to the calcaneal bone.  Flat and broad tendon called aponeuresis.Flat and broad tendon called aponeuresis.  For exp ; epicranial aponeuresis (scalp) and bicipitalFor exp ; epicranial aponeuresis (scalp) and bicipital aponeuresis (cubital fossa)aponeuresis (cubital fossa)
  39. 39.  Have the arrangement of actin and myosin and theHave the arrangement of actin and myosin and the same bands, zones and Z discs as skeletal muscles.same bands, zones and Z discs as skeletal muscles.  Unique characteristic – intercalated discsUnique characteristic – intercalated discs  Intercalated discs – connect the end of cardiac musclesIntercalated discs – connect the end of cardiac muscles fiber with one anotherfiber with one another  Contain desmosomes, and gap junction.Contain desmosomes, and gap junction.  Contain endo and perimysium but lack with epimysium.Contain endo and perimysium but lack with epimysium. Cardiac MusclesCardiac Muscles
  40. 40.  Contraction rate 10 – 15 times longer thanContraction rate 10 – 15 times longer than skeletal muscles.skeletal muscles.  Due to Ca2+ enter the sarcoplasm from SR andDue to Ca2+ enter the sarcoplasm from SR and interstitial fluid.interstitial fluid.  Contraction stimulated by its own autorhythmicContraction stimulated by its own autorhythmic muscles fiber.muscles fiber.  Mitochondria – larger and numerousMitochondria – larger and numerous Cardiac MusclesCardiac Muscles
  41. 41.  Activated involuntary = cardiac musclesActivated involuntary = cardiac muscles  Two types ; visceral and multiunitTwo types ; visceral and multiunit  Visceral – wall of small arteries and veins, stomach,Visceral – wall of small arteries and veins, stomach, intestine, uterus and urinary bladder.intestine, uterus and urinary bladder.  Multinunit – wall of larger arteries, airways to the lungs,Multinunit – wall of larger arteries, airways to the lungs, arrector pili muscles etcarrector pili muscles etc  Spindle shaped and nonstriated fiber – smoothSpindle shaped and nonstriated fiber – smooth appearanceappearance Smooth MusclesSmooth Muscles
  42. 42. Smooth MusclesSmooth Muscles
  43. 43.  Consists single, oval, centrally located nucleus.Consists single, oval, centrally located nucleus.  Sarcoplasm contains both thick and thinSarcoplasm contains both thick and thin filaments.filaments.  Lack transverse tubul and small amount of SRLack transverse tubul and small amount of SR contain Ca2+.contain Ca2+.  Ca2+ sources fromCa2+ sources from caveolaecaveolae (small pouch like(small pouch like invagination form plasma membrane)invagination form plasma membrane) Smooth MusclesSmooth Muscles
  44. 44. Smooth MusclesSmooth Muscles
  45. 45. Muscular tissues has four special properties that enable itMuscular tissues has four special properties that enable it to function and contribute to homeostasis:to function and contribute to homeostasis: 1.1.Electrical excitabilityElectrical excitability 2.2.ContractilityContractility 3.3.ExtensibilityExtensibility 4.4.ElasticityElasticity Properties of Muscular TissueProperties of Muscular Tissue
  46. 46. Electrical ExcitabilityElectrical Excitability  Ability to respond to certainAbility to respond to certain stimuli by producing electricalstimuli by producing electrical signal (action potential orsignal (action potential or impulses)impulses) Properties of Muscular TissueProperties of Muscular Tissue
  47. 47. ContractilityContractility  Ability of muscular tissueAbility of muscular tissue to contract forcefullyto contract forcefully when stimulated by actionwhen stimulated by action potentials.potentials.  When muscles contract, itWhen muscles contract, it will generates tensionwill generates tension (force).(force). Properties of Muscular TissueProperties of Muscular Tissue
  48. 48. ExtensibilityExtensibility  Ability of muscular tissue to stretch without being aAbility of muscular tissue to stretch without being a damaged.damaged. Properties of Muscular TissueProperties of Muscular Tissue
  49. 49. ElasticityElasticity  Ability of muscularAbility of muscular tissue to return to itstissue to return to its original length andoriginal length and shape after contractionshape after contraction or extension.or extension. Properties of Muscular TissueProperties of Muscular Tissue
  50. 50. Producing body movementProducing body movement  Contraction of muscles –Contraction of muscles – movement of the whole of themovement of the whole of the body (walking, jumping, running)body (walking, jumping, running)  Localized movement – grasping aLocalized movement – grasping a pen, nodding the headpen, nodding the head Function of Muscular TissueFunction of Muscular Tissue
  51. 51. Stabilizing body positionStabilizing body position  Contraction of skeletal musclesContraction of skeletal muscles stabilize joints and help maintainstabilize joints and help maintain body position ; standing, sittingbody position ; standing, sitting Function of Muscular TissueFunction of Muscular Tissue
  52. 52. Storing and moving substancesStoring and moving substances within the bodywithin the body  Cardiac muscles contraction –Cardiac muscles contraction – pumped the blood throughout the bodypumped the blood throughout the body  Ring shaped smooth muscles –Ring shaped smooth muscles – sphincter help prevent form back flowsphincter help prevent form back flow of the foodof the food Function of Muscular TissueFunction of Muscular Tissue
  53. 53. Generating heatGenerating heat  When muscular contractionWhen muscular contraction occurs, it produces heatoccurs, it produces heat  This process known asThis process known as thermogenesisthermogenesis  Important for maintainImportant for maintain normal body temperature.normal body temperature. Function of Muscular TissueFunction of Muscular Tissue

×