KIN 3309 1nd Edition Lecture 3 Outline of Last Lecture I. Hierarchy of StufII. Types of Solid MaterialsIII. Stress and StrainIV. Stress-Strain CurveV. QuizVI. QuizVII. Musculoskeletal SystemVIII. Functions of the SkeletonIX. Architecture of BoneX. Types of Bone TissueXI. Types of BoneXII. Bone TissueXIII. Ossification, Modeling and RemodelingXIV. Bone TissueXV. What would happen if the activity of bone cells was out of balance?XVI. Bones and Physical ActivityXVII. Material Properties of BoneXVIII. QuizThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.XIX. QuizXX. Load Applied to BoneXXI. Injury?XXII. CartilageXXIII. Articular CartilageXXIV. FibrocartilageXXV. LigamentsXXVI. Stress Strain Curve for LigamentsXXVII. Synovial JointXXVIII. Types of Synovial JointsXXIX. Joint DegradationXXX. QuizXXXI. QuizXXXII. SummaryOutline of Current Lecture I. MuscleII. Types of MuscleIII. Characteristics of MuscleIV. Function of MuscleV. Groups of MuscleVI. Muscle ArchitectureVII. Muscle Volume and Cross SectionVIII. Fiber OrganizationIX. Fiber OrganizationX. Fiber TypeXI. Individual Muscle OrganizationXII. Sliding Filament TheoryXIII. Motor UnitXIV. Muscle ContractionXV. Muscle Twitch and TetanusXVI. Muscle AttachmentXVII. Characteristics of a TendonXVIII. Mechanical Model of a MuscleXIX. Hill Muscle ModelXX. TorqueXXI. Muscle Roll versus Angle of AttachmentXXII. Roll of MuscleXXIII. Agonist versus AntagonistXXIV. Net Muscle ActionsXXV. Factors Influencing Muscle ForceXXVI. Force-Velocity RelationshipXXVII. Force-Length RelationshipXXVIII. Stretch-Shortening CycleXXIX. Muscle FatigueXXX. Strengthening MuscleXXXI. Principles of TrainingXXXII. Strength Training and NonathleteXXXIII. Training ModalitiesXXXIV. Injury to Skeletal MuscleXXXV. SummaryXXXVI. QuizCurrent LectureI. Musclea. Comprises largest group of tissues in bodyb. 3 types of musclei. Skeletal muscle1. Voluntaryii. Cardiac muscle1. Involuntary iii. Smooth muscle1. Involuntary c. Classified in two diferent waysi. Striated or unstriatedii. Voluntary or involuntaryII. Types of Musclea. Skeletal Musclei. Is associated with bony skeleton, and consists of large cells that bear striations and are controlled voluntarilyb. Cardiac Musclei. Occurs only in the heart, and consists of small cells that are striated and under involuntary controlc. Smooth Musclei. Is found in the walls of hollow organs, and consists of small elongated cells that are not striated and are under involuntary controlIII. Characteristics of Musclea. Irritabilityi. AKA excitabilityii. Ability to respond to stimulationiii. Stimulation: is provided by a motor neuron releasing a chemical neurotransmitteriv. Skeletal muscle tissue is one of the most sensitive and responsive tissue1. Skeletal muscle can be recruited quicklyb. Contractilityi. Ability to shorten when it receives sufficient stimulation: tensionii. Unique to muscle tissueiii. Some skeletal muscles can shorten as much as 50% to 70% of their restinglength1. The average range is about 57% for all skeletal musclesc. Extensibilityi. Ability to stretch/lengthen beyond the resting lengthii. Protective mechanism1. Protect from injury because it is more elasticityiii. The skeletal muscle itself cannot produce the elongation by itself1. Another muscle or external force is required2. Example: pushing another’s limb past its resting lengthiv. The elastic material so it can elongate beyond original resting positiond. Elasticity (Flexibility)i. Ability to return to resting length after being stretched ii. Protective mechanismIV. Function of Musclea. Produce movementb. Maintain postures and positionsc. Stabilize jointsd. Other functionsi. Support and protect visceral organsii. Alter and control cavity pressureiii. Maintain body temperatureiv. Control entrances/exits to the bodyV. Groups of Musclesa. Muscles typically act in unison, not individuallyi. Single muscle cant be activated by itselfb. Groups of muscles are contained within compartments defined by Fasciac. Fasciai. Sheet of fibrous tissueii. Compartmentalizes groups of musclesVI. Muscle Architecturea. Paralleli. The fascicles are parallel to the line axis of the muscleii. Flat, fusiform, strap, radiate (convergent) circularb. Pennatei. Fibers run diagonally with respect to a central tendon running the length of the muscleii. Unipennate, bipennate, multipennateVII. Muscle Volume and Cross Sectiona. MV = m/pi. Mass of the muscle (g)ii. Density of the muscle (g/cm2)b. Anatomical cross-section (ACS)i. A measurement of the cross-sectional area perpendicular to the longitudinal axis of the musclec. Physiologic cross-section (PCS)i. A sum total of all of the cross sections of fibers in the muscleVIII. Fiber Organizationa. Fusiformi. Parallel fibers and fasciclesii. High speed of contact, force productioniii. ACS = PSC1. Anatomical cross-section (ACS)2. Physiologic cross-section (PCS)iv. Sartorius, biceps brachii, brachialisIX. Fiber Organizationa. Penniform – Three typesb. Unipennatei. Of one side of tendonii. Semimembranosusc. Bipennatei. Of both sides of tendonii. Gastrocnemiusd. Multipennatei. Both varieties ii. Deltoide. PCS > ACSi. Penniform fibers have a bigger PCS than ACS X. Fiber Typea. Type 1i. Slow-twitch, oxidativeii. Red (because of high myoglobin content)iii. Slow contraction times, well suited for prolonged, low-intensity workb. Type 2ai. Intermediate fast-twitch, oxidative-glycolyticii. Rediii. Sustain activity for long period or contract with a burst of force and then fatiguec. Type 2bi. Fast-twitch, glycolyticii. Whiteiii. Provide rapid force production and fatigue quicklyXI. Individual Muscle Organizationa. Myofibrili. Contractile element of muscle fiberii. Contain sarcomeresb. Sarcomerei. Functional unit of skeletal muscleii. Found between 2 z lines (connects thin filaments of two adjoining sarcomeres)XII. Sliding Filament Theorya. A.F. Huxleyb. Seeks to explain production of tension ine musclec. Myosin and actini. Create cross-bridgesii. Slide past one anotheriii. Cause the sarcomere to contractXIII. Motor Unita. A motor neuron and all the muscle fibers it innervatesb. Smallest unit of the neuromuscular systemc. The number of muscle fibers in a motor unit (innervated by 1 motor neuron) variesi. Gastrocnemius1. 2,000 muscle fibers per motor neuronii. Extraocular muscles1. < 10 muscle fibers per motor neurond. Ratio of muscle fibers to motor