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WOW Nervous System 1/31/06. It senses the bodies surroundings to allow it to interact. It controls all of the other body systems. Why is the nervous system so important?. How is the Nervous system organized.?. The central nervous system. The peripheral nervous system.
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WOW Nervous System 1/31/06 • It senses the bodies surroundings to allow it to interact. • It controls all of the other body systems. • Why is the nervous system so important?
How is the Nervous system organized.? • The central nervous system. • The peripheral nervous system.
How is the Nervous system organized.? Nervous System Central Nervous System Peripheral Nervous System Brain Spinal Chord Somatic Voluntary from skin to CNS and skeletal muscles. Autonomic Involuntary from CNS to Internal organs Sympathetic During Times of stress Parasympathetic. During Times of rest
I. Neurons are nerve cells specialized in sending electrochemical signals. What do we call nerve cells?
What are the three main types of neurons? 1. Sensory Neuron- sense stimulus and carry impulse to the brain Grab a hot pan 2. Interneuron's found in CNS, process stimulus and pass on to motor neurons. Thought process. Run, hold tighter, or throw it down. 1. Motor Neurons Carry response from CNS to muscles to stimulate action Throw it down and yell %3@%$#.
How are nerve impulses sent? • Uses Ions Na+ and K+ • Cell membrane has protein channels; • Voltage-gated channels • Only allow Na+ and K+ • Closed when neuron at rest • Negative charge inside
What is action potential? • Voltage gates open allow, Na+ to enter. • Inside becomes positive causing K+ to • leave. • This sudden change in voltage causes • another Na+ gate to open. • One action potential (AP) causes another • AP to occur further down axon. • Sodium and Potassium pumps use active • transport to restore original balance.
What speeds up the impulse? • A myelin sheath covers axon and allows impulse • to pass through axon faster. • Impulse jumps from node to node.
What happens when impulse reaches the end of the axon? • Nerves do not touch each other. • 2. Nerves separated by Synapses. • 3. Nerves send chemical messages through synapses. • Neurotransmitters are passed from axon to next neuron. • Bind to protein gates in next neuron. • Opens ion gates and triggers AP in next neuron.
Impulse reaches end of axon Neuro’s released. Neurotransmitter released reabsorbed Bind to protein receptors Dissolved into axon
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