NERVE IMPULSE TRANSMISSION OBJECTIVES 4 Explain how nerve

NERVE IMPULSE TRANSMISSION OBJECTIVES: 4. Explain how nerve impulses are generated and how they are conducted along a nerve fiber (pp. 877 – 879) 5. Describe the mechanism of nerve impulse transmission at the synapse. (pp. 877 – 879)

I. Neuron at rest Outside is Positively charged due to Na+ ions. Inside is negatively charged due to Nucleic Acids and Proteins

II. When the neuron is stimulated • NA+ rushes in and creates the “Action Potential” • The inside is now positive(Action Potential). AP Action Potential

III. How does the neuron reset itself? 1) Reset Charge: K+ exits neuron AP Action Potential

III. How does the neuron reset itself? 2) Reset Ions K+ / Na+ pump resets the ions back to normal Action Potential

What happens: 4. Neurotransmitter released into Synapse 1. Impulse reaches end bulb 2. Ca 2+ channels/gates open 5. Neurotransmitter binds to receptors and Ca 2+ enters on adjacent neuron, causes it to 3. Vesicles migrate and fuse with depolarizes membrane

Transmission Across a synapse Lab 1) Obtain a microscope and slide 2) On your paper, draw a picture of your slide on 400 power. 3) Find the neuron and label the following parts on your picture: – – Axon Presynaptic neuron Vesicles Postsynaptic muscle

Questions 1) What causes the vesicles in the neurons end bulb to release its contents? 2) What carries the nerve impulse across the synapse? 3) What is another name for a nerve impulse?