Neural Control of MovementCENTRAL NERVOUS SYSTEMCENTRAL AND PERIPHERAL NERVOUS SYSTEMPERIPHERAL NERVOUS SYSTEMSENSORY NEURONSMOTOR NEURONSPowerPoint PresentationSpinal NervesSlide 9NEURON ANATOMYSlide 11Proprioception and KinesthesisMUSCLE SPINDLESSlide 14Slide 15Slide 16GOLGI TENDON ORGANSlide 18Slide 19Other ReceptorsSlide 21NEUROMUSCULAR CONCEPTSMotor UnitFactors Affecting Muscle TensionSlide 25Slide 26Neuromuscular SummarySlide 28Slide 29Slide 30Slide 31Neural Control of MovementChapter 2CENTRAL NERVOUS SYSTEM•Brain–Cerebral Cortex/Cerebrum•Motor cortex –Basal Ganglia/Diencephalon – sensory input–Cerebellum – motor control–Brain stem – sensory input•Spinal CordCENTRAL AND PERIPHERAL NERVOUS SYSTEM•Central nervous system•Peripheral nervous systemPERIPHERAL NERVOUS SYSTEM•Somatic–Sensory (Afferent) Neuron–Motor (Efferent) Neuron•Autonomic [FYI]–Parasympathetic–SympatheticSENSORY NEURONS•Carry impulse towards the CNSTowards CNSMOTOR NEURONS•Carry impulse away from the CNS (e.g. motor nerves)•Stimulatory•InhibitorySpinal NervesCervical spinal nerves (C1 to C8)These nerves (eight pairs) supply the back of the head, the neck and shoulders, the arms and hands, and the diaphragm.Thoracic spinal nerves (T1 to T12)These nerves (12 pairs) supply the chest, some muscles of the back, and parts of upper abdomen.Lumbar spinal nerves (L1 to L5)These nerves (five pairs) supply parts of the lower abdomen and the back.Sacral spinal nerves (S1 to S5)These nerves (five pairs) supply the thighs and parts of lower legs, and the feet.NEURON ANATOMY•Dendrite•Cell Body•AxonNEURON ANATOMYNeuron…a single nerve cellNerve….a bundle or group of neuronsA nerve contains both motor and sensory neuronsProprioception and Kinesthesis•What is kinethesis?•…awareness of the position and movement of the body•What is proprioception?•…ability to regulate posture and movement by responding to stimuli from receptors throughout the bodyMUSCLE SPINDLESMUSCLE SPINDLESProvide proprioceptio nSense the amount of stretch and the rate of stretch Reflexes involving the muscle spindles is how we ‘feel’ a movement was done correctlySpindles are a part of learning; we develop such reflexes as we practice skills and movementsGOLGI TENDON ORGANGOLGI TENDON ORGANSensitive to muscle tension and active contractionProtect muscle from excess contraction forceStimulation of GTO an afferent impulse is sent to the central nervous systemIn turn, efferent impulses are sent to the……Agonist muscle causing it to relax…Antagonist muscle causing it to contractOther ReceptorsProprioceptors of the joints and skinExamples: Meissner’s corpuscles, Ruffini’s corpuscles, Pacinian corpuscles, Krause’s end-bulbsNEUROMUSCULAR CONCEPTSMotor Unit•One motor neuron and all the muscle fibers it innervates•All-or-none principleFactors Affecting Muscle Tension•The number of motor units activated•Type of motor units activated (fast or slow twitch)•The frequency of stimulation of the motor unitsFactors Affecting Muscle Tension•Stimulation•Subthreshold stimulus•Threshold stimulus•Submaximal stimulations•Maximal stimulationFactors Affecting Muscle Tension•Twitch•Summation•TetanusNeuromuscular Summary•An example from baseball.•A pitcher throws a curve ball to Derrek Lee•Derek’s eyes see the ball coming towards him and is able to identify the pitch as a curve ball•Sensory nerves (afferent) send that information to the CNS•In the CNS the sensory nerve synapses with motor nerves•The motor nerves in turn stimulates the muscles (deltoid and pectoralis major) required to swing the bat in the proper position to hit the ballNeuromuscular Summary•Inside the fibers of the deltoid and pectoralis major, calcium is released•The calcium allows myosin heads to attach to actin•When the heads swivel the fibers of the deltoid muscle will shorten•The shortening of the fibers will pull on the humerus causing Derrek to swing the bat•The muscle spindles “tell” the CNS when the arm is in the correct position•If all goes as planned, the deltoid and pectoralis major will move his arms into a position to hit the ballNeuromuscular Summary•An example from weight training.•A man is having his muscular strength tested on the bench press•For his first lift, 50 pounds is put on the bar•He will be using his pectoralis major muscle with has 500 motor units (300 slow twitch and 200 fast twitch) and his triceps muscle•His CNS stimulates 280 motor units leading to his pectoralis major muscle (180 slow twitch and 100 fast twitch)•Remember, each nerve ending stimulates a separate muscle fiberNeuromuscular Summary•The pectoralis major and triceps muscles shortens and his arm extends outward raising the bar with 50 pounds on it.•After a few minutes of rest, 100 pounds is place on the bar•This time he stimulates 380 motor units (260 slow twitch and120 fast twitch)•The weight is successfully lifted•After a few minutes of rest, 150 pounds is place on the barNeuromuscular Summary•This time he stimulates 460 motor units (280 slow twitch and 180 fast twitch)•As the pectoralis major muscle contracts the GTO in the pectoralis major are stimulated•They stimulate a sensory nerve leading to the CNS•In the CNS, the sensory nerve synapses with a motor nerve that will inhibit (relax) the pectoralis major muscle•The man is unable to lift the 150