Neural Control Of Jumping

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Neural Control Of Jumping

  1. 1. Neural Control of Jumping By: Jenna and Kelsey!
  2. 2. <ul><li>The peripheral nervous system (PNS) contains sensory nerves that sense changes in an individual’s environment </li></ul><ul><li>When a sensory neuron senses a change it sends an action potential to the spinal cord which sends the message to the brain </li></ul><ul><li>The brain or the spinal cord, which makes up the central nervous system, (CNS), depending on the severity of the change, interprets the message </li></ul><ul><li>The CNS sends back a response through an action potential back through a motor nerve which tells the muscle what to do in response to the change </li></ul>
  3. 3. Sensory neurons, the 5 senses, starts the neural message
  4. 4. <ul><li>The neuron is initially in a resting potential state where it is negative on the inside of the cell and positive on the outside. This is created by a sodium potassium pump that actively transports Na+ and K+ across the cell membrane. </li></ul><ul><li>Depolarization is the action potential traveling along the neuron. Depolarization begins when the stimuli opens sodium channels causing a temporary change in the cells polarization.(Relative to one another- positive on the inside, negative on the outside) </li></ul><ul><li>Repolarization begins immediately following depolarization where the resting potential is restored. This is known as the refractory period. </li></ul>
  5. 5. <ul><li>The gap between neurons is known as a synapse. </li></ul><ul><li>Communication across the synapse happens by Ca++ rushing into the neuron through voltage-gated channels. </li></ul><ul><li>This increase in Ca++ causes synaptic vesicles to fuse with the pre-synaptic messengers and spill neurotransmitters into the synaptic cleft by exocytosis. </li></ul><ul><li>Neurotransmitter is received by the post-synaptic cell because receptors recognize the neurotransmitter. </li></ul><ul><li>This causes ion channels to open and impulse is transmitted. </li></ul>                                            
  6. 6. <ul><li>The somatic motor neuron that innervates skeletal muscle fibers is called a motor neuron. </li></ul><ul><li>The axon of the motor neuron extends to the muscle that it is responsible for innervating. </li></ul><ul><li>Once the axon reaches the muscle, which is known as the neuromuscular junction, it splits into collateral branches which innervates a single muscle fiber. </li></ul><ul><li>Each motor neuron and and all the muscle fibers that it innervates is known as a motor unit. </li></ul><ul><li>When a single motor neuron is activated, all of the muscle fibers that it innervates are stimulated to contract. </li></ul><ul><li>The more nerves there are telling the muscle to contract the higher an individual can jump, known as Neural-Plasticity. </li></ul>
  7. 7. <ul><li>Fast twitch muscles have to do with anaerobic metabolism due to due to less myoglobin and mitochondria </li></ul><ul><li>Fast twitch muscles fatigue quicker, b ut are better at generating more power in short bursts than slow twitch muscles are </li></ul><ul><li>Slow twitch muscles have a lot of myoglobin, which carries oxygen </li></ul><ul><li>Slow twitch muscles have higher aerobic metabolism and mitochondria and are therefore more capable of endurance activities or activities that do not require maximum strength. </li></ul><ul><li>Jumping uses more fast twitch muscles than it does slow twitch. </li></ul>
  8. 8. <ul><li>Muscle spindles are small sensory organs that are enclosed within a capsule </li></ul><ul><li>A muscle spindle detects changes in the stretch of the muscle </li></ul><ul><li>A muscle spindle assists in the regulation of movement and helps maintain posture. </li></ul><ul><li>A muscle spindle sends signals to the brain then the brain sends the signal back to the quadricept telling it how much to stretch or contract before a person is about to jump. </li></ul>
  9. 9. <ul><li>A golgi tendon is located at the insertion of skeletal into the muscle fibers of skeletal muscles. </li></ul><ul><li>They serve as “safety devices” that help prevent excessive force during muscle contraction. </li></ul><ul><li>Golgi tendon organs send how far the individual wants to jump to the spinal cord through sensory neurons which travels to the brain. </li></ul><ul><li>The brain interprets the sensory message and formulates a response, sends the message back through motor neurons which tells the gogli tendon organs how much to monitor the muscle contraction before the individual jumps. </li></ul>
  10. 10. <ul><li>Neuromuscular fatigue results when the synapse is not being communicated over </li></ul><ul><li>This happens when the neurotransmitter, acetylcholine, is blocked by free radicals and the impulse fails to cross the synaptic cleft </li></ul><ul><li>Therefore the muscles get a delayed message or no message at all to contract resulting in a less powerful jump. </li></ul>Key: Acetlycholine Free Radicals Receptors

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