KIN 3309 1nd Edition Lecture 4 Outline of Last 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 MuscleThese 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. 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. QuizOutline of Current Lecture I. Organization of the Nervous SystemII. Central Nervous SystemIII. Peripheral Nervous SystemIV. NeuronV. Motor NeuronsVI. Structure of a Motor NeuronVII. Neuromuscular JunctionVIII. Motor UnitIX. Types of Motor UnitX. Motor Unit PropertiesXI. RecruitmentXII. ReflexXIII. Proprioceptive ReceptorsXIV. Muscle SpindleXV. Golgi Tendon Organ (GTO)XVI. Joint Sensory ReceptorsXVII. Cutaneous ReceptorsXVIII. Strength TrainingXIX. Flexibility TechniquesXX. Proprioceptive Neuromuscular Facilitation (PNF) StretchingXXI. Plyometric TrainingXXII. Electromyography (EMG)XXIII. What can be learned from an EMG?XXIV. EMG InstrumentationXXV. Types of EMGXXVI. Surface ElectrodesXXVII. General ConcernsXXVIII. Characteristics of EMG SignalXXIX. Characteristics of Electrical NoiseXXX. EMG RecordingXXXI. EMG AnalysisXXXII. EMG ApplicationXXXIII. EMG During WalkingXXXIV. SummaryXXXV. QuizCurrent LectureI. Organization of the Nervous Systema. Central nervous system (CNS)b. Peripheral nervous system (PNS)c. Neurond. Motor neuronsII. Central Nervous Systema. Where human movement is initiated, controlled, and monitoredb. Braini. The center of our thoughtsii. The interpreter of our external environmentiii. The origin of control over body movementc. Spinal Cordi. The highway for communication between the body and the brainIII. Peripheral Nervous Systema. Branching nerves outside of the spinal cordb. Connect the CNS to the limbs and organs, essentially serving as a communication relay going back and forth between the brain and the extremitiesIV. Neurona. Functional unit of the nervous systemV. Motor Neuronsa. Carry signals to the muscleVI. Structure of a Motor Neurona. Has a synaptic gapVII. Neuromuscular Junctiona. Motor end platesb. Neuromuscular junctionc. Synapsei. Small gap between the terminal branch of neuron and muscleVIII. Motor Unita. Groups of motor units often work together to coordinate the contractions of a single muscleb. All or non principlec. All fibers in a motor unit are of the same typed. Type 1, 2a, 2bIX. Types of Motor Unita. Type 1: slow twitch (s)i. Slow contraction times (>70 ms)ii. Generates little tensioniii. Highly fatigue-resistant iv. Maintaining posturev. Distance runnerb. Type 2a: Fast twitch oxidative (FR)i. Fast contraction times (30 to 50 ms)ii. More fatigue-resistant than type 2biii. Swimming, bicyclingc. Type 2b: Fast twitch glycolytic (FF)i. Rapid contraction times (30 to 40 ms)ii. Innervated by alpha motor neuronsiii. Large neuron-to-fiber ratiosiv. Sprinting, jumping, weight liftingX. Motor Unit Properties XI. Recruitmenta. How to describe the activation of the motor unitsb. Tension generated is determined by the size and number of motor units recruitedc. Order of motor unit activationi. Size principle1. Type 1 activated first  type 2a  type 2bd. Asynchronous activationi. Activation is temporally spaced but summed with preceding motor unit activityii. First one activated first and the next one is activated later, its integrated in a special domaine. Synchronous activationsi. Large and small motor units activated together 1. Ballistic movements, adaptation from weight trainingf. Frequency codingi. Also called rate codingii. High frequency can induce high tension productiong. Small musclesi. All units activated when at 30% to 50% maximum voluntary contractionh. Large musclesi. Still recruiting units at 100% maximum voluntary contractionXII. Reflexa. Involuntary neural response to a specific sensory stimulus and is a stereotypical behavior in bother time and spaceb. Types of Reflexesi. Myotactic reflex1. Also called stretch reflex2. Causes contraction of a muscle being stretchedii. Flexor reflex1. Initiated by painful stimulus2. Causes quick withdrawal/flexion of the limbiii. Cutaneous reflex1. Causes relaxation of muscle with heat or massageiv. Propriospinal reflexes1. Reflexes processed on both sides and at different levels of the spinal cordv. Crossed extensor reflex1. Causes extension of flexed limb when contralateral limb rapidly flexesvi. Tonic neck reflex1. Causes flexion or extension of the limbs when head flexes or extends, respectivelyvii. Supraspinal reflexes1. Reflexes brought into the spinal cord but processed by brain viii. Labyrinthine righting reflex1. Causes body to return head to neutral position when body is tiltedor spunXIII. Proprioceptive Receptorsa. Sensory receptors in the musculoskeletal systemb. Transform mechanical distortion in muscles or jointsi. Change in joint position, muscle length, and muscle tension into nerve impulsesii. Enter the spinal cordc. Muscle spindled. Golgi tendon organXIV. Muscle Spindlea. Is found in higher abundance in the belly of the musclei. Lying parallel to the muscle fibersii. Connecting into the fascicles via connective tissueb. Monitors muscle stretchc. Intrafusal fibersi. Are contained within a capsule, forming a spindle shapeii. Nuclear bag fibers or nuclear chaind. Gamma motor neuroni. Innervates contractile ends of the muscle spindlee. Gamma biasi. Readjustment of the muscle spindle length by contracting ends of intrafusal fiberf. Gamma loopi. Reflex arc that works with stretch reflexii. Includes afferent, gamma, and alpha pathwaysg. Primary afferenti. Type 1aii. Respond to stretch by initiating stretch reflexh. Secondary afferenti. Type 2ii. Facilitate flexors and