Slide 1Muscle AnatomySlide 3Motor UnitMuscle Fiber StructureSlide 6Sliding Filament TheoryPhases of Muscular ActivationNeuromuscular SystemMuscle Fiber TypesMotor Unit Recruitment PatternsProprioceptionCardiovascular SystemThe HeartCirculatory SystemThe Respiratory SystemThe Respiratory SystemRespiratory SystemChapter 2: Bioenergetics of Exercise and TrainingBioenergetics: Key TermsEnergy SystemsPhosphagen SystemGlycolytic SystemOxidative SystemTake Away PointsSubstrate DepletionSpecificity of TrainingANNOUNCEMENTSCHAPTER 1Structure and Function of the Muscular, Neuromuscular, Cardiovascular, and Respiratory SystemMuscle Anatomy•Tendon- attaches bone to muscle•Muscle Fibers-muscles cells•Fasciculi-bundles of muscle fibers•Perimysium- Connective tissue surrounding Fasciculi•Endomysium- Connective tissue between Muscle Fibers•Sarcolemma- Membrane Surrounding Muscle FibersMotor Unit•Motor Neuron- nerve cell•Neuromuscular Junction- space between nerve cell and muscle fiber•MOTOR UNIT= Motor Neuron + Neuromuscular Junction + Muscle FibersMuscle Fiber Structure•Sarcoplasm- the cytoplasm of muscle cells: contains contractile components, enzymes, mitochondria, and Sarcoplasmic Reticulum•Myofibrils- contain the apparatus that causes the cell to contract-primarily composed of Myosin and ActinSliding Filament Theory•Actin filaments at the ends of the sarcomere slide inward on myosin filaments•Z-Lines pull towards the center of the sarcomere•Muscle fiber shortens•Rapid, repeated flexions must occur in many cross bridges through the entire muscle for movement to occurPhases of Muscular Activation•Resting Phase•Little Calcium present (most in Sarcoplasmic Reticulum-SR)•Few Myosin cross-bridges are bound to actin•No tension in the muscle•Excitation-Contraction Coupling Phase• SR releases Calcium, Calcium binds to Troponin•Myosin attaches to Actin•Flexion occurs, amount of force determined by # of myosin bound to Actin•Contraction Phase•ATP breaks down to form ADP•ATP must continuously be replaced for contraction to cont.•Recharge Phase•Actin and Myosin dissociate, recocking of myosin cross-bridge head•Relaxation Phase•Stimulation of motor nerve stops•Calcium pumped back into SR•Actin and Myosin return to unbound statesNeuromuscular System•Motor Neurons activate multiple muscle fibers•Action Potential- electric current that flows down a Motor Neuron•All or None Principal- all of the muscle fibers a motor neuron innervates fire fully or not at all. Stronger or weaker AP’s don’t change the amount of fibers, or the force developed.•Activation of the sarcolemma releases Calcium, this initiates the contraction process.Muscle Fiber Types•Type I- Slow Twitch- slowER rate of firing•Type IIa- Fast Twitch- fastER rate of firing•Type IIb- Fast Twitch- fastEST rate of firingMotor Unit Recruitment Patterns•Frequency of Activation- frequently activating a motor unit causes force to summate (important for small, fine movements)•Increase in Recruitment- force is increased by activating MORE motor units•HINNEMAN’S SIZE PRINCIPLE- motor units are recruited in order from smallest to largest. TRAINING IMPLICATIONS???•Very rarely (although highly trained individuals can activate more at once, than an untrained person) are all muscle fibers activated at once. WHY???Teen lifts car to save grandpa'Supermothers' and grandfather lift 1 ton Renault Clio off trapped schoolboySuper Strength: Daughter Rescues Dad Pinned Under CarProprioception•Proprioceptors are specialized receptors that provide the CNS with information on muscle tone and help perform complex movements•Muscle Spindles- modified muscle fibers, detect stretch in the muscle fiber, sends signal to CNS leading to contraction•Golgi Tendon Organs- proprioceptors located in the tendon, activated when the tendon attached to the muscle is stretched due to muscle contraction; leads to relaxation in the muscleKEY QUESTION: How can the GTO negatively effect your ability to lift heavy weight????Cardiovascular SystemPrimary Roles:1. Transport Nutrients2. Remove Waste3. Maintain Homeostasis-Temperature-Acid/Base Balance-Fluid LevelsThe Heart•Two separate pumps (right and left side)•Each pump has two chambers (atrium, ventricle)•The Right Ventricle pumps blood to the lungs•The Left Ventricle pumps blood to the body•Valves in the heart prevent back flow; open and close passively when the pressure gradient is overcome•A conduction system electrically controls contraction of the heart muscleCirculatory System•Arteries- carry blood away from the heart•Arterioles- small arteries, carry blood away from the hear•Capillaries- smallest blood vessels, where exchange occurs•Venules- small veins that carry blood from capillaries to veins•Veins- blood vessels that return blood to the heartThe Respiratory SystemThe Respiratory System•Primary Function: Exchange of AirAir in and out of the lungs is controlled by expansion and relaxation of the chest cavity•Expiration and InspirationExpiration = elastic recoil of the diaphragm (relaxed=larger)Inspiration = contraction of the diaphragm (contraction=smaller)Respiratory SystemNOSETRACHEABRONCHIBRONCHIOLESALVEOLIChapter 2: Bioenergetics of Exercise and TrainingBioenergetics: Key Terms• Bioenergetics- the flow of energy in a biological system•Catabolism- the breakdown of large molecules into smaller molecules, associated with the release of energy•Anabolism- the synthesis of larger molecules from smaller molecules… the building up process. Ex: Anabolic Steroids•Metabolism- the total of all the catabolic and anabolic reactions in a biological system•ATP- allows the transfer of energy from catabolic reactions to anabolic reactions. Without ATP, muscle activity and growth would not be possible!!!Energy SystemsThree basic energy systems exist to replenish ATP Stores:1.Phosphagen System 2.Glycolytic System3.Oxidative SystemKEY POINT: These systems are classified as either anaerobic (no oxygen) or aerobic (oxygen present). The phosphagen and part of the glycolytic systems are anaerobic. The second phase of the glycolytic system and the oxidative system are aerobic. CHO is the only macronutrient that can be metabolized without Oxygen present.Phosphagen System•Provides ATP for short-term, high-intensity activity•Active at the start of ALL ACTIVITIES•Relies on the hydrolysis of ATP and Creatine Phosphate (PCr)